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Resin types: Water Soluble vs PLA
With resin LCD printers (not filament!), what are the considerations to choose between PLA and "water soluble"? Microcenter carries resins from esun in these two types, and their spec sheets indicate that tyhe water-soluble type has higher tensile strength and other mechanical properties. Which leads me to wonder, under what circumstances one selects PLA then?

First of all, let's look at what the filaments are:
PLA & PVA Filaments
Normal PLA and Water-soluble PVA contain for the most part the material on the tin, its precursors, and possibly some modifiers. These are only suitable for thermoplastic processes like injection molding or  FDM/FFF (Filament deposition modeling/Fused Filament Fabrication) printers - the finished polymer can't be made back into a UV-curable resin easily. Both materials are chemically rather well bonded and are not very reactive at all. They are biodegradable and not a lot of toxic waste. PLA needs very strong chemicals such as dichlormethane to go into solution, but PVA is water-soluble.
Resin
Almost no cured resin (as in post-polymerized) is water-soluble, your webshop might have a misnomer as it meant to write the proper name: water-washable, which is meant to reflect the ability to put the unpolymerized monomers into solution in water.
eResin
eSun offers an eResin-PLA-Bio-Photopolymer, which is similar to PLA, but it is not the same material you get for an FDM printer. You see this most easily by checking the density and the MSDS: Real PLA has a density of 1.21–1.43 g/cm³, eResin (as the bottles are labeled) has a density of merely 1.07-1.13 g/cm³. This is a totally different material in the bottle! It is most likely a resin mix that is based on lactic acid monomers and a UV-active acid that can bond the monomers, creating a structure that does contain lactic acid groups and the binder - but most certainly it is not chemically identical to PLA. It contains, according to the MSDS, Polyurethane acrylate as the 'binder', 1,6-Hexanediol diacrylate Monomers, and about 10 % photo inhibitors and pigments. The main selling point seems to be, that comparable to PLA, it would be made from a renewable source to a larger part. The chemical reaction that leads to the completed resin is a question I have pitched on Chemistry.SE.
It needs to be cleaned with IPA (isopropyl alcohol) or another organic solvent like any standard resin and you are not allowed to rinse the material into the sewer: it is classed as a LONG-TERM AQUATIC HAZARD - Category 4 and its MSDS contains:

Solubility：Soluble in ethanol, ethyl acetate, benzene and other organic solvents, insoluble in water

water-washable eSun Resin
eSun offers no water-soluble resin at all, they offer a water washable resin, which means that it is supposed to be less toxic than standard resin and safe to rinse effectively without IPA, creating less toxic waste in the process. The MSDS for this is not (yet)) available so I can't evaluate this. However, I have requested the MSDS for the evaluation of safety procedures needed and hope to hear back from them soon. This resin is most certainly not PVA, but it seems to be chemically somewhat similar to their other resins.

Thank you! Looks like the eSun PLA is not PLA is the answer... and your material safety cleanup seems to be a valid answer. I also noticed some colors (white) seem to be available in only one of the chemistries... maybe temporary but also a distinction.

@0xF2 Added some information, also nice that you correcte your initial error about LED. Because the chemistry of the compound seems interesting, I asked over at Chemistry.SE, maybe someone there can aide in telling us what the resulting resin-print should be classed as.


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How to prepare bed for printing ABS filament?
I have never used ABS filament before, so my question is, how do I prepare my glass build plate for printing ABS filament?
My second question, is, after you have prepared it, and have finished printing, can you 3d print with other plastics, such as PLA after?

ABS can be a problem to print, but there are generally a couple well established methods to prepare your glass bed, which might be combined for best results:

Heated bed. A heated bed is almost a must for ABS and would be set to about 75 to 90 °C for most printers. Often this can suffice on its own, but keep the bed running for the whole print!
ABS-Slurry. One of the best functioning adhesive helpers is ABS-Slurry, which is made by mixing a little acetone with as much ABS filament as it will solve, then applying a thin layer of this compound to the glass bed right before the print. It will stink a lot, but it most certainly will offer one of the best adhesions you can get and might even prevent Warping due to the stronger bond to the bed.
Rafts. You might want to add a raft of at least 2 layers under the print. The Raft can be removed in the end, but it increases the surface area and can often help to reduce the chance of warping.

Now comes the good part: you just need to remove all the ABS residue and the bed is ready for the next preparation for any other material. This can be done with a scraper blade quite easily, maybe some Acetone and then alcohol if there are some really nasty bits.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


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Resin printer build plate scratches/ damage
I have an anycubic photon, and occasionally have trouble removing prints from the build plate. While trying to removing prints I've put some scratches into the surface, as I guess I've come in at the wrong angle trying to get under and leverage the print.
Typical examples I've seen of people removing prints, they appear to come at it hard with a blunt edge. I've come across scrapers that are blunt and some with a sharper edges.
I've put a bit more a ding into my plate today, using a scraper with more of a blade edge for a difficult to remove print. I had used the same scrapper before with great success, as it slide right under and I could leverage the print, but struggled with it today and scratched up my plate.
I haven't come across much discussion on this so thought I'd ask about scratches to the build plates.
Are scratches to the build plate something to be concerned about, is it something that it expected when removing prints?

One of the resources I've found is a forum with a discussion of the impact of scratches.
The general consensus is that scratches are not a problem, as long as there are no burrs above the surface of the plate that would damage the bottom of the vat. One posting party has used 36 grit on a palm sander followed by scotchbrite pad to resurface his plate, but one takes the risk of creating an out-of-plane surface.
A better method to sand a plate would be to place the sandpaper on a glass surface or something equally flat and planar and pass the build plate repeatedly over that.
Another aspect of the discussion was that scratches are good, as the rough surface provides a better bond to the resin.
You're likely to note that your build plate is not a polished smooth surface for the same reason.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Vertical vs Horizontal shapes printing
first time here.
I recently bought an Anycubic Mega S and I'm venturing in the 3D world. Lots to learn for sure. I have printed a few items so far and all went pretty well.
My question is about something that caught my attention while browsing on Thingiverse. I was looking for an organizer for a board game that I have and every option I found there shows the piece in a vertical position rather than horizontal which seems like the natural position of the piece.
I would like to know why most of this types of pieces are set to be printed in a vertical position rather than horizontal.
Here is the original piece Betrayal at Baldur's Gate Organizer by Jason Patch. As you can see in the image below the piece is naturally horizontal but the actual files to print (blue ones) are all vertical.

PS.: I didn't really know which tags to use so I just added 3D, feel free to suggest any other I will happily edit it. :)

Thingieverse does respect the orientation an item was designed in, just like most slicers will. Designers will often choose any one of the three planes (XY, YZ, ZX) as their first by preference, then work out the other parts in relation to the first. This does often not take into account the actual print orientation it should be printed in.
In the case of this box, you'd have to turn all items around the Y-axis (the front-left to back-right one) by 90°, first to the front, then the back then to the front again, getting almost 0 overhangs.

When I design parts in CAD software I pick a starting plane and go from there. And that starting plane doesn't correspond to how the part is designed to be printed. That usually comes later.


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PETG grinding with direct drive extruder
I've been wrestling with a filament grinding problem for a few weeks now and I'm stuck.
The problem manifests itself as starting a print alright then extrusion stops while the printer keeps moving. When I pull the filament out I see indents from the gear then a depression where it ground down the filament.
Filament used is 1.75 mm Spool3D PETG on a Hictop printer, which is a clone of a Prusa i3. I don't know the exact part number though. The extruder is direct drive, and the 28 mm heatbreak is connected to a heatsink block rather than something with fins. Nozzle is standard 0.4 mm.
My print settings are quite conservative. Speed is 20 mm/s, retraction is 20 mm/s (though it never grinds on retraction), temperature is 255 °C, which is 10 °C higher than what works in my other printers. No print cooling.
At first I thought there was a clog, but I can push the filament though by hand quite well. I also use cleaning filament frequently and it never pulls out any debris. Heatbreak and nozzle have been changed to fresh items.
Does anybody have any other ideas of things I can try, or should I just get a new extruder?

In the past I solved heat creep issues with PLA (a filament which conducts heat relatively well) by having a small fan blowing fresh air on the extruder gear, which in my case was exposed so it was easy to do. It worked very well.

This does sound a lot like you are experiencing the effects of heat creep (How is heat creep characterized?). You should lower the temperature of the hotend and increase the printing speed and retraction speed and possibly lower the retraction length.

If this is heat creep, a new extruder will not help you until you solve the heat creep first. A new hotend that can be cooled better might be a better solution.

Additionally to the answer of @0scar:

If the problem happens in the first layer, it can be that the z-offset is not properly setup: if the first layer is too thin, the printer cannot extrude (enough) plastic, and the filament will warm until the gear cannot extrude it any more. The solution is to have the perfect first layer thickness (so it stick well, but extrude the correct plastic amount).
Release a bit the gear pressure on the filament: If the gear is too tight, with the temperature, it start to penetrate/deform the filament, and then is not able to move it.

Indeed! Also, many users (not me) generally require a little more offset between the nozzle and the bed when printing PETG.


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Do thermistors degrade in accuracy without hard failure?
Lately I've been having problems with overhangs not adhering when curvature is outward (stringing across instead) that look like what you'd see at insufficient temperature, and that go away with temperature jacked up a bit (PLA at 220 °C, which is a bit extreme) or fan disabled. Is it possible that the hotend thermistor has drifted and is no longer accurate, making the actual temperature lower than nominal? Or do these things fail hard when they fail?

This is an interesting question, but, isn't this best asked at EE.SE? You are hinting to electronics degradation.

There might be better experts there but I'd really like to hear an answer in the context of 3D printing, especially if anyone has experienced similar.

To begin with, is the value at room temperature still reliable? If you can disconnect the thermistor from the fuser, can you test it in boiling water? these two tests allow a check at least. You can also recalibrate the beta.

Buying multiple thermistors and keeping one for future reference unused after an initial 100h burn-in is also an idea.

Yes, thermistors can drift in value as well as outright failing (usually open).
In my experience this is not uncommon in thermistors operated above 100 degrees C. The drift is typically downward in resistance so the controlled temperature will be less than the desired setpoint, which is exactly what you are observing.

Most thermosensors are functionally nothing different but a temperature dependant resistor. As such, our boards usually use $U=RI$ to get to the resistance, and then compare that to a temperature table. In effect, they put in a regulated potential difference, and measure how much current flows. Plugging this into $U/I=R$ gives the Resistance, which then gives the temperature from the table. In fact, since U is assumed fixed in most firmware, the lookup can also be done directly via the current.
In theory, a resistor's resistance follows $R=R_0(1+\alpha \Delta T)$. Now, Alpha is the proportionality factor of our resistor, delta-T the difference to the tested temperature, at which point the resistor gives R0. Note that Alpha might be also temperature dependant, which is why the firmware looks up the table, not calculates it fresh. So far so good, right? Well... one more thing. Under the standard conditions, we can also use $R_0=\rho \frac l A$ to learn about the resistor, the resistance is the specific resistance times length divided by crossection area.
Now, from just the many factors that play into the thing, we have several points where we might gain error over time:

The Thermosensor's resistor itself might break down, for example by operating it too hot. In this case, the factor $\rho$ as well as the effective crossection area get altered. Such a resistor will show a resistance under no heating outside of the known good value. To do this, you'd need to operate your thermosensor above its rating, usually that's in the area of 250 to 290 °C. As an example, the standard e3D Thermosensors are good till about 285 °C, but they also have ones good for up to 500 °C, while the welded thermocouples are only safe for -50 to 250 °C due to it's PTFE sleeve. Removing said sleeve allows to use it for a larger temperature area, but that is not listed.
The wiring might be damaged. If the wires to the Thermosensor are kinked and effectively thinner, they might add extra resistance. This would be detectable by measuring the leads to the resistor - they should in best case have close to $0\ \Omega$ resistance. As the wiring is the most stressed part usually, and the wire bundles are often packed well enough to not show up too much even if some strands are broken, such should show up only in the very last stages before a total failure.
The board might not measure correctly, for two reasons: either it might look at the wrong reference table as you might have swapped to a different type of thermosensor in a repair, or it might use the wrong (too little/too much) potential difference U to obtain it's measurement I and thus look in the wrong row of the table. For this, there is a fix available in the firmware by swapping to the correct temperature table or calibrating your own one for your off-standard voltage. The latter is a highly involved process and needs you to measure against a known temperature repeatedly.

I am not affiliated with e3D; they are merely one of the best-documented stores for replacement parts I know about, which is why I consulted their catalog.

We also assume that temperature and resistance have a linear relationship. From experience with strain gauges, that only mostly holds true., and I would expect it to drift less true over time (e.g. mechanical cracking plus thermal expansion starts giving a more variable cross-sectional area). Additionally, the temperature transfer from the heater to the thermistor is likely variable.

Yep, that's why I wrote Note that Alpha might be also temperature dependant,

I don't think it is the thermistor degrading. To answer your question directly, all my thermistors have failed because the tiny wire has broken off, and generally the fail is “hard” not soft.
It is more likely you’re experiencing absorbed humidity in the filament from it being out on the spool too long. this makes you have to increase the temperature.
I’m sure if you dehydrated the spool in the oven for a bit you’d get better prints and a slightly lower print temp.
Additionally, keep in mind that a lot of PLA on the market nowadays runs at higher temps because it’s laced with something (“PLA+”?).  Check the item description for indicators of a new or improved formula.
You could try ordering a thermistor of the same make and testing the temperature of it. You can get a half dozen for about \$10. The Marlin firmware your printer probably uses should have a section for thermistors and what kind you’re using. It’s probably type “1” which is the cheap kind.
You can try using one of those distant head thermometers to measure the temperature wirelessly at the hot end.  These are probably over \$100 right now because of COVID. I think that is how a well-resourced person would handle this (i'm not one personally).
Maybe start with the oven and while it’s cooking, research the thermistors and what goes in to replacing one. It’s a good learning experience because one day your hotend may be irreparably clogged and you’ll want to know some of the steps to disassemble it.

What type of thermometer do you mean? The IR (+ laser targeting) ones? Are they accurate on reflective metal surfaces?

Moisture in the filament is a good thought. I'll check that out as a possible cause. I don't have any sort of "PLA+", very intentionally - I want the rigidity of PLA. (See CNC Kitchen's latest video on the topic, which is very nice.)

I don't know about the distant thermometers personally. I should've added that I am not a well-resourced person. There have been a few times that I wish I had one though, so it could've been a worthy buy for me before COVID.

It is indeed possible that the thermistor is broken (yet not sure). I am aware of two types of issues with thermistors:

The contact (soldering) is broken, usually due to the temperature extreme variations. The thermistor will indicate the maximum temperature in case of PTC or minimum temperature in case of NTC. In some cases, due to vibrations or other factor, the contact will eventually touch, showing improbable jumps of temperature.

The thermistor is broken internally. In that case it will just indicate a wrong temperature. I can't say if constant temperature or constant delta.

For how to troubleshot the component, however, EE.SE seems more convenient.

Printer heats up fine and PID loop is stable. I'm just not sure if it's at the same final temp (relative to requested temp) that it used to be.

I suppose you don't  have a thermometer to troubleshot this temperature right?

I was thinking about getting one but I don't know what type is suitable for measuring temperature of the hotend/nozzle.

Adding my 2 cents...
In practice thermistors hard fail. They do not "drift" fast enough for an application to notice. What's most likely happening (assuming that the problem is the temp) is that the reference voltage that is being used to determine the resistance of the thermistor could be faulty. As a simple test, you should get a basic thermometer to measure the temperature of the room. Then check it against the printer when it is sitting idle. If the 2 temps differ by more than 1 degree, then something is wrong. Check if the bed and nozzle thermistors are reading the same value (again to within 1 degree). If they are not, then swap the leads and see if if you get the same problem (with the printer idle of course).
If you have access to a multimeter, then measure the resistance of the thermistor, and then look up what the resistance should be at a certain temp (there are tables for this on the internet).

note that if you use an anaogous thermosensor to compare against, you might just notice a miscalibration of the thermosensors - alcohol and mercury thermometers are almost ridiculously accurate compared to most digital ones.

@Trish, true. I should get a mercury thermometer as well.

NTC Thermistors can fail progressively due to moisture, cracking, changes in the material structure. Don't forget that you are operating them at neat the maximum temperature, not at room temperature.
In this article about NTC resistors for current limiting (subjected to current pulses, but tested also for high temperature stress) they say:

Process of degradation of NTC thermistors has complex character and
is, in considerable degree, determined by the total number of applied
current impulses or thermal cycles. Initial rise of resistance is
caused probably by oxidation process or modification of ionic
distribution.

Luckily, after an initial burn-in, they are stable for quite some time. You may just need to recalibrate. Or use a PT1000 resistor which should not have similar issues, and which works without any additional electronics.
See also here for a statement by a manufacturer that NTC ages:

At room temperature the polycrystalline material shows solid-state
reactions which lead to an irreversible change in the characteristics
(usually resistance increase, change of B value etc). Physical reasons
for this may be thermal stress causing a change in concentration of
lattice imperfections, oxygen exchange with the environment (with
unprotected, non-glass-encapsulated thermistors) or diffusion in the
contact areas of metallized surface contacts. At low temperatures
these reactions slow down, but at high temperatures they accelerate
and finally decline with time. To enhance long-term stability, our NTC
thermistors can be subjected to an aging process directly after
manufacture.

See this graph from this page for drift as function of time and temperature:


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Roll back from Marlin 2.0 to manufacturer closed-source firmware
Because I needed to insert nuts in my prints and therefore G-code instructions in their file, I upgraded my printer firmware to Marlin as in here :

At the beginning I did used to get the 6 beeps when booting, and was able to boot back to the initial firmware when hiding the upgrade.cbd file in a folder, instead of the root level of the SD card.
But I did by mistake load/save some settings to the EEPROM I guess, and I cannot get back to the initial firmware - at boot time there isn't any beep anymore and it boots directly on the marlin boot wallpaper.
How to prevent Marlin forcing the 3D printer to boot on it please?

Note that you probably never had to upgrade to Marlin 2.0, you could have inserted a pause or at least a dwell command in your older firmware.

I tried this https://3dprinting.stackexchange.com/questions/14191/cant-manage-to-force-my-print-to-standby-while-i-insert-a-nut-prusa-slicer-an , what is a dwell command please? Also I needed to modify the nozzle to prober offset because the stock fan duct was bumping into the prints and idk if it's feasible on chitu boards

https://3dprinting.stackexchange.com/questions/14191/cant-manage-to-force-my-print-to-standby-while-i-insert-a-nut-prusa-slicer-an#comment25520_14191 see also G4: Dwell

Thanks a lot! I will try it as soon as I get back to my initial UI !

Tried this https://www.tronxyonline.com/Firmware-XY-Series-a63177.html but after launching the gcode print and restarting, Marlin persists...

what did you do to actually get to the problem in the first place?

I'm not sure to remember but I think I miss-pressed store settings in the motion>bed-leveling touchscreen UI


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Curing a resin print
After a resin print completes, what is the expected process to finish the print? Is some cleaning expected? I also some manufacturers sell UV chambers to cure the print surface, is this required?
I purchased a low-cost printer from China that is quite high-quality hardware, but sadly short on documentation. Insight on the proper post-print process is appreciated.

Yes
You need to do a two-step post-processing:
Washing
This is basically as easy as taking the print and dropping it into a vat of Isopropyl alcohol and vigorously shaking it to get all the liquid resin off. Careful, the resulting contaminated IPA is to be treated as toxic waste.
The reason why you wash the print is to make sure no resin stays on it and cures, distorting the print or altering the measurements.
Post-Print-curing
The next step is just having the item sit in UV light to cure thoroughly, which means either having it sit outside in sunlight or under a UV lamp. Under sunlight, it might take a few hours, under a UV lamp, it depends on how thick the object is and you might need to turn and rotate the printed part. Note that some resins, especially transparent ones, can change their coloration when exposed to sunlight, both during or after curing.
Curing is done to ensure all the resin is fully cured and get the full stiffness out of the print - sometimes prints are still somewhat malleable before giving them time to cure.

Some resins will discolor if cured via sunlight. This is not a factor if the intent is to paint the model.

@fred_dot_u True and added - even a fully cured item can discolor under sunlight, it's the light breaking down some parts in the resin.

I did recently notice a translucent's print transparency changed after UV chamber curing.

You don't really need a UV curing chamber but wash it with 99 % isopropyl alcohol
and put it in bright sun, this should do the trick!!

"Bright sun" is the biggest UV source, and not always availeable.

hmm just try in midday?

have you heard about the odd concept of clouds and work?

what are ClOudS And wOrK?


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Error:Printer halted. kill() called! SKR 1.3 TFT35 3.0
I am trying to fix the very last error on my printer (custom built).
Error:Printer halted. kill() called!

This error occures about 5-10 minutes into a print (XYZ Cube) and usually after finishing the second layer.
All temperatures are working as far as I can tell: heats up fine (if a little slow) and all sensors are working; 50 °C bed, 190 °C hotend, all axis are moving, homing and stepping fine and I haven't noticed any overheating issues on the steppers themselves. I have the SD card plugged into the screen rather than the mainboard as it had difficulty reading from the mainboard when I first tested it.
After this happens I can no longer move any axis from the interface and have to run a power cycle to get control back.
Parts:

BTT SKR 1.3 (Marlin 2.0, TMC2209 drivers UART)
TFT35 3.0 (Latest firmware)
NC X/Y endstop switches
Inductive Z Probe (generic blue square one)
Dual Z steppers
J-Head v6 hotend

Notes:
I dont have much knowlage of Marlin firmware, so please be descriptive if I am missing something in the firmware (e.g. "edit //#define DUAL_Z_STEPPERS in Marlin/Configuration_adv.h" to define the use of dual Z steppers by altering the line to #define DUAL_Z_STEPPERS)
It's not possible to plug my printer into a computer, it's over 5 m away, my laptop is broken and I haven't set up my Raspberry Pi yet.
I do not know how to set up SD card logging if that is even a posibility.

A USB extension cable isn't that expensive anymore! My 5 m one saved me a lot of times! :-) This error message is common in case the firmware thinks the hardware is getting into trouble, have you monitored the temperature of the nozzle when it shuts down? E.g. is the part cooling fan kicking in?

I don't have a part cooling fan, only a hotend fan (need to print a bracket for part cooler) is there Sd card logging?

SD card logging can be done with M928 log.txt, to stop logging use M29.


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Increase hotend temperature on Monoprice Ultimate 2
I'm fairly new to 3D printing and I have a Monoprice Ultimate 2. The Monoprice website says it can reach 250 °C with a 100 °C bed temperature.
I want to print some projects using Matterhacks Nylonx, its recommended printing temperature is 250 °C to 265 °C.

Could I print it on the stock max setting of 250 °C or will it not adhere correctly?
Can I increase the print temperature by replacing the hotend with an E3D hotend?

If so how hot could I get the hotend and how would I go about doing that?

There is not many resources about Monoprice products.  Any help is greatly appreciated.

Ok, first of all you need to understand why the limit is given at 250 °C: that's when the hotend design chosen by the Monoprice starts to destroy its PETG liner. To print hotter, you'd need an unlined hotend, which means you'd need a proper all metal hotend.
A proper all metal hodend is a tradeoff, not an upgrade: you sacrifice some ease of printing and risk some clogs in the lower temperature band for being able to print higher temperatures.
When you want to buy an e3D hotend, you should go for a genuine one, as many clones are actually not all metal. Also note, that there are other all-metal hotends around.
If you get an e3D v6, you should make sure to buy the right variant for your machine! Monoprice tells us, that this is a 24 V Machine, so you'll need to get the 24 V Variant! As you also will swap the temperature sensor, you might need to update your firmware according to the e3D installation manual. Since a genuine hotend comes with all the cabling and a new thermosensor, you'll need to rewire the whole machine - and you might need to make new fittings before installing. The standard e3D Thermistor that comes with the hotend is good up to 285 °C, which will be your new ceiling temperature. Take careful note of these two parts that appear in the before assembly notes section of the manual:

The standard V6 is capable of printing up to 285°C, do not exceed these temperatures unless you have replaced the Thermistor cartridge with a PT100, the Aluminium heater block with a Plated copper heater block, and the Brass nozzle for a Plated copper, Hardened steel or Nozzle X.
Firmware modification is not optional it is a mandatory step.

Don't forget the temperature sensor, it might be worth mentioning that although you can increase temperatures with an all metal hotend, there is a limit to the thermistor. For 265 °C a thermistor will be adequate enough.

Will it be compatible with the voltage and wires going to the ironical hotend? And if I add a new temperature sensor, will it display an accurate temperature on the screen?

@0scar the ceiling is 285 °C for the standard e3D thermosensor.

@Noobmaster69 if you get a 24V one, yes. You will have to make your own firmware though, as firmware modification is necessary to up the ceiling to 285 °C and to set the thermosensor properly.

Thank you, this may be too hard for me, will https://www.matterhackers.com/store/l/black-pro-series-nylon-175-3D-printer-filament/sk/MCR8GQZT work for my printer with stock settings?

@Noobmaster69 that material is 240 to 260 °C, so it might work, if you are willing to go into the upper range of your printer. I wouldn't demand more than 245°C to keep a little overhead and not trigger maxtemp errors.


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Printing and slicing big pieces with Elegoo Mars (Pro)
I'm pretty new in the 3D printing world, and there are some doubts that have come my way and I've not been able to find anywhere.
Usually, I'm going to try to print pieces bigger than the bed of my Elegoo Mars Pro (which is 115 x 65 x 150 mm, so it's pretty small). Everywhere I try to look at this they are talking about Fused Filament Fabrication (FFF) printers, and I guess that material will make the answer to these questions to be different, that's why I'm asking here. All of these questions are focused on SLA printers.
Is there any kind of technique / slicer software to be able to print those pieces by parts?
I've read about slicers, but there seem to be a bunch of them, and some of them work best with some printers than others, and have different features but I haven't seen any that helps in this matter.
Also, I've seen the typical plane cut, but this doesn't make it easy later on to "fit" pieces. I would need some kind of female - male joint. Is there any (free) slicer that helps in that, and makes those joints to be accurate and solid?
Thank you!

I removed the "shrink size" part in the question and published it as a separate question. Also moved to a different question "gluing separate pieces" part.*

@Trish yes, you're totally right! I've already done that! Thank you for your suggestion!

With so many questions, I'll provide a suggestion for your first one, the alignment option. There's a 12 minute YouTube video showing how to use Meshmixer (free, multi-platform) to create alignment pins and holes while segmenting a model for printing large items.

The process involves making the cut, keeping both sections. A pin is created and sized, then placed in one of the faces, while the other segment visibility is turned off. The pin is then triplicated, with one pin moved away for printing.
One of the two remaining pins (overlapped) is selected and is used for a Boolean subtract operation, creating a hole that is matching in size and location.
The first segment visibility is turned off, the second segment is turned on and the pin is selected again. The sequence is duplicated, creating a second, matching hole.
I didn't watch the entire video, but if it is not suggested, one should reduce the third pin size, at least the diameter, sufficiently to allow it to fit the holes created by the above process.
Note that the video has some inconsistencies from my experience. Some terms are changed from the video to the program, but should not cause problems.

Thank you so much for your answer. I've already published the shrinking part into another question to keep it clearer (see edit). And that's more or less what I was looking for. I guess that the short answer is that is not possible to make parts that are very precise in terms of joints, as you run the risk of making unable to snap at all?

If you use a Square or hexagonal pin instead of a round one, the method described also makes the pin work as a quite effective alignment tool. Another option would be to use 2 pins. I suggest to scale the "peg" down about 0.3 mm in diameter for FDM, but on an SLA/DLP you might get away with a 0.1 mm thinner one.

The video does suggest a square or non-cylindrical peg and I've used a pair, well, a pair of pairs to ensure alignment.

Ok! I see! Yes, it seems that the square is best if you don't want the pieces to move, because even if it's shrinked or smaller (or not very precise with the joints), it will prevent it from rotating because of its squared shape. That's a good thing to know!

I actually found it easier to export my model as a single STL file, and then to open up 3D builder. It has a tool that let's you create a flat plane, and then slice a model into pieces using it.
So long as you have a large enough surface area to glue, it shouldn't be a problem.
I tried using booleans and the peg\hole method in Blender, but it simply wasn't stable enough with complex models.
Where I have used pegs and hole I used round pegs or the simple reason that they are easier to sand down to the right size if they deform and are too tight a fit.

Yeah! I actually discovered 3d Builder a few weeks ago, and since its last update it works pretty well. The only thing is that it's just splitting it (not adding any joints), so you better make sure that your print comes out 100% flat and without issues or it's going to be fun trying to make that fit!

I try to place the slice plan along natural ridges on a model, for example the waist of a statue to cut it in half so that I can print the top and bottom at the same time.


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Curated resin size shrink (and methods to reduce it)
I've recently purchased an Elegoo Mars Pro 3D printer.
I've read about that percentage of resin shapes going smaller and I understand that. But are slicers (or software which help with the joints) already taking that into consideration? Resines vary, and with them that percentage varies too, so is the software applying that error margin or am I the one responsible on this?
Also, is that shrink percentage constant? Like everytime I print 5 mm it will shrink to 4.7 mm, or it depends on how is curated and other random values so it could be one 4.6 mm and the next printed shape to be 4.8 mm?
It depends on the curation process, or the printing process? If I print 2 separated parts alltogether in one single print session, both will have the same shrinkage, or it will depend on the curation process of each of them individually?
If it's not constant...
How can I ensure that all parts printed separately will fit together when joined later on and it won't create a sort of Frankenstein figure where nothing fits? Is there any process to reduce that shrinking to a minimum, even if it takes longer for each shape to cure?
I'm not referring to "clipping parts", but edges and so. If I join two separate parts together, and one of them is smaller than the other because of the shrink of the resin, then the edges won't fit and won't be a clean join.

This is less printer but much more resin dependant. You might experience different results on the same printer with different types of resin!

Generally, this behavior isn't well reearched as of this moment, and it would be dependant on your specific resin. While I can't tell you if your resin is affected by shrink or even uneven shrink, I can give you the method of how to investigate:

Download or design a cube with a well-known dimension. I'd suggest a cube of 20 mm side length. It's best to indent the orientation onto the surfaces. One such model would be thing 3090144, which has a version that is hollow and has a hole to let out resin, but there are others.
Align the X, Y and Z with the letter into the positive side of the axis in your slicer.
Print.
After Printing, clean and cure
Only after curing, measure the X and Y and Z dimensions with calipers.
Calculate shrinkage: Measurement divided by 20 gets you the shrinkage or expansion, multiply by 100 for percent.

Thank you for your answer! I guess the only way to find an answer to some of my questions is just wasting resin and testing for it (and for every kind of resin I use). I will leave the question open, however, to see if someone can answer with ways to reduce the shrinkage amount. Thank you!

@Unapedra true, you will need to sacrifice some resin and print time, but until someone does a scientific study on the matter, this is the best I can offer a the moment.


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SLA resin post-processing: gluing parts together
I've recently purchased an Elegoo Mars Pro 3d printer, and I was wondering when printing large pieces that need to be printed in different steps: is there some kind of post-processing to make it more suitable for gluing them?
I know of joints and so on, but sometimes pieces are big but not thick enough to be able to put a joint somewhere, so I guess the only solution would be to glue them.
Should I use some kind of specific glue to get better results with resins? Is there any process (post-processing, reducing layer height when printing, leave the resin being curated more time...) to improve the sticking of the different parts? Or can we go with any kind of "strong multisurface glue" without any further post-processing steps, and the results should be the same in matters of quality?
Thank you!

this is not printer dependant, but mostly dependant on your exact resin.

As I learned after asking about the chemistry of a 3D printing Resin, the material uses radical polymerisation to get a well connected, branched copolymer. It is comparable to resin cast material but more brittle. So let's look, akin to the PLA-gluing question, what we can do!
Step 0: Safety First!
Some of these methods are working with chemicals that can irritate the skin (resins, cyanoacrylate) or have irritating or flamagle fumes (heated cyanoacrylate).
Use proper protection when working with these! Eye protection and respiratory protection, as well as gloves, are to be used when necessary. Read the manual of the products you are working with!
Preparations
For most glues, it is advisable to prepare the surface: very lightly sand it to increase the surface area, don't touch the prints with bare hands to prevent fingerprints etc. Follow the manual!
Glues
As a result of the chemistry I would suggest the following glues:

The resin itself! Carefully applying a thin layer of the printing resin onto the cured parts and then pressing the parts together before letting it cure again will get you a good bond that might not even be visible as you have exactly the same material. Note though, that you might be able to assemble the part between washing and curing for absolute minimal visibility of the gluing surface and maximum bonding. Also note, that for a non-transparent resin (fully opaque to 400 nm light) you'd better look for a different gluing system, as the bond will be much weaker if it can harden only at the edge.
Cyanoacrylate, aka Superglue. This glue is pretty much a one-serves-all, though it might cloud your surface. Also, not all superglues are the same, and some might work better than others or store differently.

Together with talcum powder, CA glue can fill gaps easily.
CA is not stable under heating and when heated too much, if breaks apart into a rather noxious fume!

2-phase epoxy or polyurethane. Another glues everything category, that should work rather well. The epoxy bonds are harder, the polyurethane ones are a little more flexible, but both bond very well with cured resin. As resin prints don't really deform under heat, you might take even faster-curing types.
2-phase Putty - in a similar vein come 2-phase putties like Green Stuff or Miliputt, which harden after mixing. Their heat generation isn't too big and they allow to fill gaps easily. My favorite stuff though is not the expensive modeling putty but the stuff from the home depot: stuff like Pattex Repairsorry, no English site for this or UHU Repair All Powerkitt harden within an hour, are surprisingly cheap and get a smooth surface.

Other methods?
Unlike PLA, we can not use thermic methods to add inserts, friction-weld or weld/solder two parts together as Resin prints are generally not thermoplastic.

Thank you so much for your answer! Very complete, and exactly what I was looking for! Just a question: if I have two separate parts and I choose to use the resin as the glue, the resin should be applied in the edges, doesn't it? I mean, it could not be applied in inner parts (for example, bottom of the top part, and top of the lower part), because it would not get UV light to be cured once they are pressed together. Am I right? Thank you!

Depending on the color of your resin, and because of the system of the curing, a transparent print should be fine on the whole area, but for a non-transparent print, you might want to resort to a self-curing glue such as CA, epoxy or Polyurethane.

You can definitely use glue - however you can also brush some of the liquid resin along the edges of the two pieces, push them together and cure them, this will fuse them together.
You don't need much, and you need to watch for drip out while curing (don't your fingers in it)


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How to improve printing over 100 mm/s with 0.8 mm nozzle?
It has been a long journey failing and printing over and over to be able to print at faster speeds. All I did mostly was trial and error. I am currently trying to wrap my head around a problem that has been asked by user:1998 (mhelvens): Can we manage to make a uniform formula for printing very fast with high temperatures? (Increasing hotend temperature to compensate for increased filament throughput)
Using Ender 3, Hero Me Gen5 with E3D V6 volcano, mdd kit 1.2, Klipper firmware
When I start printing at 215 °C (recommended temperature for my filament) everything is alright, because of initial layer speed...
When I come to 100 mm/s the print clearly fails, the plastic doesn't stick, it even swirls up and is just too solid and then it damages the nozzle when it bumps in to it...
If I start at high temperature, the print is failing at the start and then doing ok, which is equally as bad
When I have high temperature and high speed the print wont stick at the beginning...
The solution in my opinion is to gradually increase speed with temperature, adding that as a function of the firmware. Also probably involving filament flow % and pressure_advance...
Is there a formula for what I'm asking?
Can we implement it in the software or does this have to be done through trial and error all the goddamn time?

At that speed, you may be barely melting the material enough to flow, but not enough to stick. Try upping temps to compensate and let us know.

@Davo Are you referring to the second paragraph, because I tried upping the temp and it resulted in oozing, cracking, bubbling at start when the speed is slow...

@MatthieuMorin My comment was pre-edit, but I believe an approach as suggested in FarO's answer should work. You can set a temp for layer 1, and another temp for layer 2, etc.

@Davo, yes indeed, I tried it, however I've done a mistake in choosing a thermistor. I will fix that up and come back to this issue

There are no ready solutions. Check on Klipper Github to see if someone requested that, but I doubt it has been implemented.
100 mm/s with 0.8 line width and something like 0.3 mm layer height results in 24 mm^3/s. It's quite high already, since the Volcano is rated at about 20 mm^3/s.
What you could try to do is to take the GCODE you have, calculate the layer time and the total path length for each layer to get the average extrusion rate, and introduce at the beginning of each layer a M104 command with a temperature dependent on said rate.
For example, you could add 1 °C for each mm^3/s of extrusion rate starting at 15 mm^3/s.
If you want, you could also calculate the average extrusion rate not every layer but every 50 mm of extrusion. In this case, better anticipate the temperature command by one stretch, since it takes time to adapt.
Otherwise you need a Supervolcano, or a slight overvoltage of the hotend (remember that power goes with the square of voltage, so do not go above 10% overvoltage).

I have asked on Github already (https://github.com/KevinOConnor/klipper/issues/3211).  Thank you for the info! I didn't know that it was only 20 cubic mm, this might very well be the root of my problem... I will try to manually change the gcode of my test print how you described and then change if necessary. Is there any way to make a command so I save time on changing it all? Already ordered the SuperVolcano, because I'm planning to use a 1.0 mm nozzle in the future...

I found out Volcano actually has about 35 to 40 mm3 max flow. I am going to use the changeatZ 5.1.1 postprocessing cura plugin to grudually increase my print speed from 60mm/s to 166%, my temperature from 230 to 250 (I think this will need more oomph... I also think I have a broken thermistor..), and fan power from 127 PWM to about 180.

E3D themselves tested the Volcano only up to 1176 mm^3/min=19.6 mm^3/s https://3dprintingindustry.com/wp-content/uploads/2019/03/Capture.jpg I would say that above that reliability of the extrusion is not guaranteed. It seems unlikely to me that you can reach such high value on a hotend which is just a little longer than the standard V6, which is rated at 10 mm^3/s.

I just got to 19.32 mm^3/s, more than that and I experience slight layer separation, which increases with more flow rate, however I think it is tuneable, but to a minor degree. The 20 mm^3/s is kind of a sweet spot. @FarO I saw the same picture and based on it my starting profile configurations. I think I could get to about 25mm^3/s while sacrificing strength and quality.


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SLA printers: safety with resin contaminated disposals
I've purchased an Elegoo Mars Pro recently, and I've been watching hundreds of video of all kind of processes, and everyone tells the same: resin is toxic, so you should cure it before throwing it to the trash, otherwise it must be treated as toxic waste.
But I've not been able to find anything with "things that are contaminated with it". For example, if I touch with some paper the resin, I guess that I should let it cure in the sun (like putting it in a plastic box and let it cure, maybe?).
But how about the IPA? How do I treat the rests of IPA contaminated with uncured resin? I don't think leaving something flammable into the sunlight during some hours is the best I can do (maybe I'm wrong and it's totally safe?).
Also, are resins water-washable (like this one from Elegoo) as toxic as the rest? Can I wash them in the faucet, or should I use a plastic recipient with just water and wash them there? What do I do with it once I finish? May I throw it into the bath, or let it cure into the sunlight, or...?
Hope this helps me and some others to treat resin disposals as they should be! Thank you!

For general handling of a resin printer in your living space, refer to Best way to deal with Resin Printers in your living space

Partial answer (for pure resin & contaminated material) can be found in Safe way of disposing resin

Both answers give me more information about the subject and they will be useful for sure (regarding safety, there is never enough information)! Thank you so much!

The IPA with the resin in it is a chemical waste and toxic to nature. As such, it needs to be given to a chemical waste handler. But those handlers do charge by volume, so you need to find a way to handle volumes reasonably. On the one hand, this means to not use huge volumes for washing the prints but reasonably small batches, and on the other hand to try to saturate them as much as possible before giving them to disposal.
It is not safe to leave the IPA in the sun or close to a source of flame, and it would certainly be not a good idea to try to torch the IPA to try to reduce the volume, but you might manage to try to concentrate the toxic waste if you might have access to a vacuum distillation apparatus - the IPA would be able to be distilled over to be reused while the original material would end concentrated.
At the moment I am waiting for an MSDS of eSun's Water-Washable resin, but the Eleegoo one is available, and it reads that it is classed as "Aquatic Chronic Class 2" - that's better than the Class 4 which IPA-washing resins have, but it is still not Sewer-safe: Do not allow product to reach sewage system or any water source. However, water is much less of a dangerous base for the waste than IPA, making it easier to handle. This mixture too needs to go to a chemical waste handler or be made inert but the waste also can be concentrated with less danger than IPA using a similar apparatus (cold distilling out water) or even a dedicated waste cookpot/evaporation vat that is exposed to heat - though you clearly should do this in a chemical-grade air filtration unit to mitigate the chance of resin fumes escaping into the atmosphere or your work environment if you heat it more than some. The dissolved resin might not be able to cure anymore as the photoinitiator might be used up during it evaporating.

Even curated resin has to be treated as toxic hazard? I read that curated resin could be thrown away in the trash, and the only problem was uncurated resin. If it's not toxic, then I could maybe leave the contaminated water recipient into the sun (as it's not flammable as IPA) a few hours to ensure the resin leftovers are curated and then treat it as normal trash?

I didn't say that, but only talked about the uncured resin that is in solution in the IPA. I will make that clear in a little. That most certainly a toxic hazard. You can't just "cure it out" in the solution.Leaving the water in the sun will concentrate the solution as water evaporates.

Now it's crystal clear! So, even if you use water or use IPA to clean your resin printed parts, the rests of the resin and also the fluids used (even water) need to be disposed into a toxic waste facility. The difference between water and IPA is that water is much more easy to work with, has no fumes nor odors, and is easier to treat for the waste disposal facilities (if I understood well). But anyway, both of them are going to cost you a trip to your waste disposal facility. Thank you so much for the response!


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SLA printers: food-safe resin parts
I've actually read that resin printed parts are not food-safe in Reddit and Formlabs guide. However, it also says that food-safe can be achieved applying some kind of food-safe coat to the printed parts, or even printing with ceramic resin.
As an owner of a Elegoo Mars Pro, I've searched for the second - ceramic resin - and I've found nothing, so I guess it's only suited for more expensive and professional printers.
But regarding the food-safe coatings, is there any recommendation on which and how to apply them for resin printed objects? Is there any other way to achieve food-safe resin printed parts? Maybe are there food-safe resins, even though they may be more expensive (I haven't been able to find any)?
The scenarios I think that have to be considered are four:

Prints to be used for liquids: like mugs and coffee cups, or recipients to hold drinks in the fridge, for example.
Prints to be used for solids: just recipients to put dried fruits, nuts, olives...
Prints to be used while eating, which some tools may interact with: plates, bowls, which will be in contact with knifes, forks, and some other material that could scratch it.
Prints to be in contact with the mouth: this would be maybe a mix of the other, but would include forks, spoons, mugs...

I guess that the cleaning and maintenance will depend on the process to make them food-safe.

I've been searching for the net, and I've found these kind of epoxy resins. I see people use them and say it's food-safe, but I cannot see it stated anywhere. Maybe are those what I'm looking for? Maybe not because some of them are for wood (maybe they can be used in other suraces, too?)? Some samples:

Fantasy craft
Art Resin
Dipoxy resin

Hope to find a little bit of knowledge to increase safety when printing some parts and being careful about the different applications that our prints may have.
Thank you!

are you asking certified food safe?

Not exactly. I just want not to end up sick if I drink coffee from a mug printed with resin. I guess that the best would be certified food safe, but I'm not going to commercialize. Just being sure that I won't end up sick and it's safe to be used by all family members (children and so on included) is enough. And if I have to clean it by hand, it's ok too.

Dipoxy Resin is a typical 2-component casting resin. if mixed properly, it cures through and goes inert. Same for Art Resin and Fantasy Craft. Though, these are not SLA/DLP resins.

Yeah, they are not SLA resins, but covering the already SLA printed piece with these, wouldn't make that print food safe?

not if the resin is not food safe, and as I pointed out below, most cast-resins are not. silicone however is available in food safe.

Porcelite is a ceramic resin which can be cooked in a kiln at 1300 °C to obtain a 95% solid resin part. Not cheap.

Resin basics
Resins are tricky, but probably less tricky than FDM as the manufacturing process is much less likely to include contaminants in the shape of contaminated air, particles, or adding lead into the print. This is all due to the whole process of creating the polymer happening under the protection of the resin, which in its monomeric liquid state is so toxic that it is unlikely any bacteria can survive in it. But before going out on a spending spree, you need to be aware that there are basically 3 kinds of resins on the market, only one of them is for SLA. To know exactly what you get you'd need to read the MSDS, which is usually available by the manufacturer of the resin.

Two-component resins as you found in the lower half of the question. You might know them as Epoxy or Polyurethane resins. They have a base material and a hardener, sometimes called Component A and B. If mixed perfectly, they cure fully, neither hardener nor resin remains. This means it is chemically inert.
Air-curing resins. These two come as Polyurethanes and also Acrylates and you might know them better under the terms paint, lacquer or coating.
Light-cured resins, as you find them in SLA resins and all coatings that are not air-curing. These are for SLA a strange chemical mixture of a photoinitiator and then some monomers that create a copolymer while coatings can be as easy as having some initiators and the rest is a single type of monomer.

Food safety?
There are some resins is on the list of FDA approved plastics for food contact. The list is exclusive: if your plastic doesn't fit one of the listed ones, you can not use it. One example would be polyacrylate, which is defined as being "formed by melt polycondensation of bisphenol-A with diphenylisophthalate and diphenylterephthalate" - which excludes any other method of getting a polyacrylate and it prescribes exactly what basic materials are allowed.
As a result, many two-component resins and light-cured resins that don't match the exact chemistry and method to create an approved plastic/coating will not match the FDA approval list and won't get approval on their own.
Coating
But there is often a way out by applying a proper coating, for example with a sufficiently thick food-grade Polyurethane coating for dry foods. This would render the item food safe under FDA standards for the approved appication. You'd need to adhere to the proper method to apply this coating (manufacturers add those to the labeling usually), which can at times be somewhat complicated.
Insert
Another way might be to add an insert that does follow FDA standards, for example, a steel cup for liquids.

Even the polyurethane coating is for "dry food only" though. There are various levels of food grade. I found a silicone spray on the web, but it's food grade in the sense that it's "intended for incidental contact with machinery that touches food".  It's a bad bottleneck for innovation in the space.

Woha, thank you so much for such a detailed answer! I guess we'll have to wait then until 3d printers can make food safe prints.


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Anet A8 X axis drive-gear wobble
I've recently noticed that the pulley driving the X-axis belt on my Anet A8 is wobbling quite a lot. I took out my calipers and sure enough the hole wasn't centred. I ordered a new pulley (from a different manufacturer) which arrived today but it was also wobbling, though much less than my old one.
The X-axis motor does not appear to wobble at all, I've tried placing a straight object up against the shaft and ran the motor and could not perceive and wobble at all in the motor, so I know it's not the motor. Before I start ordering more of the same part I wanted to see if anyone else has had this problem or if I'm doing something else wrong (for example if the uncentered pulley is a feature and there's some magical way to mount the belt pulley onto the motor to make sure it does not wobble). My guess is that I've just ordered cheap scrap parts and need to order something more expensive.
Here is a link to a video of the wobble: https://i.stack.imgur.com/hkyxN.jpg

What type of wobble? Assume Z is along the axis: is the pulley moving in XY (uncentered hole), is it wobbling in Z (axis and hole are angled to one another), is it wobbling as a whole? a photo or short film might help. Reasons for any wobble can be the parts, but it also can be mounting method.

The hole is uncentered, there’s also a tiny angle to it, but the majority of the wobble comes from the hole being uncentered.

Can you provide measurements / type?

https://www.banggood.com/Anet-GT2-Pulley-16-Teeth-Bore-5MM-Timing-Gear-Alumium-For-GT2-Belt-Width-6MM-3D-Printer-Accessories-p-1036136.html?rmmds=myorder&cur_warehouse=CN That's the part I currently have, it wobbles less than my previous gear, but still wobbles.

@BeaconofWierd I've order multiple pulleys from AliExpress, never had a problem. Please post photos of the pulley. What can be a problem is that when the center bore is too large, the set screw will offset the center. Please measure the bore and the stepper shaft.

Both the bore and shaft are 5.0 mm, a picture won't help much since there's no visual indication that it's offset, but when I measure thickness (from the bore to the outside) it is slightly different when I rotate the pulley (about 0.5 mm). I'll upload a video of the wobble in the question.

If the shaft isn't bent, you might just have bad quality pulleys. Try swap the Y-stepper with the X-stepper. +1 for adding the video!

Might also be just the back plate that is misaligned...

@Trish Which back plate? Are you talking about the white part which the motor is mounted to?

@Trish If the stepper is misaligned on the X-Z idler block, then the pulley will not wobble, it would spin around a skew axis.

no, I mean, the part is made by combining 3 parts: the socket (holding the setscrew), the axis shaft with the teeth, and a circular plate as a guidance. If the last plate is not perfect, it looks wobbling and isn't.

Ii was becoming a little too much for a comment, thus added it as an answer what I meant.

There are several possible causes for this. From least to worst:

The part itself is good, but the faceing cover plate is misaligned. No action needed.
The part is mounted in a way that makes it wobble, re-mounting helps.
The part is bad and needs to be replaced.

So, let's see the anatomy of a Timing Belt pulley. They exist in basically 3 general types in the McMaster Carr catalog: One flange, two flanges, no flanges. I am not affiliated with them, but they are pretty much one of the parts vendors in the industry that has almost everything, making them the convenience option. In the mantra, they are the "fast-good" option with the "everything" bonus and that the catalog of parts with 3D is integrated into fusion360. A similar supplier would be RS.

The part OP ordered is the "With One Flange" design, it is 6mm wide, 5mm axle and 16 teeth. The McMaster Carr catalog has two very close matches to OP's part: 3684N11 & 3684N12, about 6$ for a part machined from a solid piece. Why is that relevant?! well, the part OP ordered is not made from a solid piece but at least two parts: the body and one flange plate, as you can see on the product picture - the plate separation I marked with yellow here:

This is where the first error appears: if the flange isn't mounted centered (in poor quality it is rarely) then it appears to wobble but actually doesn't. But the video shows that the axis seems to be straight, while both the front and backside of the pulley wobble in the XY position. This means it is not just the flange that is mis-mounted on the part.
Now, error number 2 is misaligned mounting. In case the bore is good, you can often fix a misalignment by removing the part and mounting it again, more carefully, possibly using some thin shim metal around the axis. In some cases there is a pair of screws already to do this, if not it can help to modify the part with one or two extra alignment screws, allowing to sift the gear's center a slight bit by tensioning the additional screws.
In the case of OP's linked part, the screw that is not radial but protrudes next to the axis is designed to come over the flat of the axis and the other one is to tighten it down.
If the bore for the axis however is really skewed, and even after repeated re-mounting or shimming nothing can be done, a new part is needed. With the measurements of the part, you can order at a lot of online catalogs, the price and quality differ greatly. However, the engineering mantra strikes:
Cheap, Fast, Good. Choose two.


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What's the best stepper motor for BMG with very high extrusion rates?
I was recommended to buy a pancake stepper motor for a direct drive BMG extruder, however I would like to ask if the decrease in torque would still be enough to work with V6 Volcano or SuperVolcano.
If so, should I buy this pancake stepper motor and how should I configure my current setting when switching them?

A BMG extruder can be used in conjunction with the E3Dv6 hotend, the Volcano and the Super Volcano are upgrade parts for the E3Dv6 (see e3d-online), they are just differently sized heater blocks you can use to replace the normal heater block to increase the volumetric flow. In fact, it is just a v6 with a different heater block (and heater cartridge, longer nozzle threading, and often and a larger nozzle diameter). The increased heater blocks will allow for an enlarged melting zone. Although this increased melting zone, the extra length of walls will not significantly increase the resistance, most resistance comes from compressing the filament diameter to the nozzle diameter.
Note that the BMG is a similar direct extruder type as the Titan, which is produced and sold by E3D; this extruder is capable of using the Volcano upgrades using their standard pancake stepper motor (according to E3D website). You can buy these stepper motors at their website. The reason a pancake stepper is recommended is because of weight reduction (direct drive extruders carry the extruder stepper on the X-axis carriage), these extruder types gear down the speed and thus increasing the torque, a normal stepper would be too heavy and too powerful. Note that this may be a different case for 2.85 mm filament; this requires more torque anyways.


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MOSFET burned and high heated bed resistance
I am a newbie to 3D printing and I am making a 3D printer from scratch (Cartesian). I've got a RAMPS 1.4 shield and an Arduino Mega 2560 board. I have a few questions and it would be very nice if I can get answers.
The onboard MOSFET (STP55NFO6L) for the heatbed is dead and I think that the reason is because of the high resistance of my heat bed (1.8 Ω).
I have searched a lot and I am fully confused about what to do.

I am thinking of buying an external MOSFET and wire it up with the RAMPS fan MOSFET (STP55NF06L) and use the same heat bed.

Buy an external MOSFET and replace the onboard MOSFET (dead one) with the fan MOSFET (because of the underlying 11 A circuit) and use same heatbed.

Same as 2., but buying a new heatbed also.

Buying a RAMPS 1.6 and use old heatbed.

I am totally confused because of lot of searching. Please anybody help me. What should I do?

I don't have experience with that hardware, but this article on the RAMPS 1.4 shows that using an external power MOSFET module will solve 2 problems - the MOSFET and the polyfuse.

The reason for the MOSFET getting (too) hot is the high current draw of the hotbed heater, not the low resistance of the hotbed heater, although the two are related.

Thanks for replying! So basically I should buy a new MOSFET module with low RDSon and use it with same bed and wire it up with Fan MOSFET?

As I mentioned earlier, I am not familiar with that hardware, but I would think it would be better to replace the failed MOSFET. That way, you can wire up the MOSFET module to the on-board heated bed connection, otherwise you will have to make extra firmware changes. Also, you do not want to have failed components on the circuit board, because they could cause other failures.

Sounds perfect to me, thank you. And one more thing, my heat bed is mk2b 214*214 and i have read that it's high resistance is cause it support 24v also. So any idea if it's wrong or not?

There should be some indication on the bed for which connections to use for 12 V and which connections to use for 24 V. Otherwise, you will have to read the specifications for the heated bed that you have.

What is your voltage you use on the bed?

I am using 12Volts for bed.

The resistance of the heated bed being too high can not have caused the MOSFET to burn out. Only a too low resistance could cause that.
Keep in mind that measuring relatively low resistances (such as the one of your heated bed) is difficult, and if you just used a regular multimeter it might indicate a wrong value (e.g. due to the resistance of the test leads or a poor connection between the probe and heated bed). Therefore, the actual resistance might be (slightly) lower.
A 1.8 Ω heated bed at 12 V will draw around 7 A of current. This is well within the capabilities of the MOSFET on board of the RAMPS. So either the resistance of the heated bed is lower than you measured (if the resistance was 1.2 Ω or lower this could cause the MOSFET to burn out), or you simply got unlucky with the quality of your RAMPS board.
The (supposedly) high resistance definitely doesn't make the heated bed compatible with 24 V. Using a 1.8 Ω bed with 24 V would cause a 13 A current draw and 320 W of power. This is a lot more than is sensible for a 214 mm x 214 mm bed.
All of the alternatives 1 and 4 you have listed are reasonable options. There is no reason (option 3) to replace the heated bed as there is no indication it is faulty. I see no reason to take option 2 since it involves desoldering and resoldering the fan MOSFET for no reason (if you are using an external MOSFET the fuse is no longer a limitation). There is a chance you'll damage the MOSFET doing this and option 1 only requires a trivial firmware change.
Option 4 (upgrading to RAMPS 1.6) is purely a matter of personal preference.

Thank you so much. Well about the resistance i actually minus the resistance of probes from the actual reading and it's 1.8 and one more thing, can you please suggest me a good mosfet (external). I have been looking but there are so much of them and I really don't have any experience with such stuff. Please!


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Is there any commercial supplier of 3D printed parts made from acrylic (PMMA)?
I was surprised to learn that, AFAICT, neither Protolabs, Xometry, or Shapeways* can supply 3D printed parts from acrylic.  Is anyone aware of a commercial source of 3D printed parts made from acrylic [polymethylmethacrylate (PMMA)]?
*Shapeways does 3D print their "Fine Detail Plastic" which is an acrylic.  However, during the printing process, the material is UV cured so, AFAIK, it is no longer a thermoplastic (as PMMA is).  I need the thermoplastic property for my application.

Are you trying to get optically clear prints?

Hi Perry, not necessarily.  I need prints in acrylic as I need both its thermoplastic properties and its non-polar solvent properties.

While I don't know of PMMA as a standard offering, I do know that a lot of the smaller entities will gladly accommodate custom requirements for the right price and an understanding that results may be inferior to their tried and true.
My recommendation is to google "3D Printing Service" and find what's local.  Local will hopefully mean you don't have to wait for a shipment to review the quality.

Having melted acrylic on various occasions, I can hazard a guess why FDM isn't popular with this material: not only does it give off an acrid odor, the melted material is sticky and viscous, likely too much so to make into filament or to print reliably if so made.  Most acrylic materials are made by curing a liquid resin, either with a catalyst ("casting resin", used among other things to make the spherical hulls of high visibility submarine vehicles) or with UV (these are different materials, but both in the acrylic family).
The "an acrylic" that Shapeways offers, being UV cured, is most likely a SLA ("resin") print.  If it's any sort of acrylic, it should still be thermoplastic, but will suffer the same disadvantages as common "Plexiglas" acrylic PMMA -- very, very stinky stuff to melt.
One thing you might consider is using the "mold" capability in Cura Slicer (not sure if other slicers have this, though apparently some mesh modifiers can replicate the effect) to produce a 3D printed mold in which to cast parts from acrylic resin sold for either fiberglass application or casting.  If you start with the correct resin type, the cured result will be nearly identical to PMMA, and you can make the mold on a common FDM printer.


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Can parts that have warped (after being printed) be un-warped?
I have an on-going project to build a large lampshade in the shape of a geodesic dome. It's made of 3D printed frames that will be covered with rice paper. I printed the parts in PLA over a month or so, but then had to ship them from Europe to Japan due to moving house.
Unfortunately, when they arrived a lot of them had warped quite badly. In retrospect they weren't packed very well, and they probably got quite hot while travelling through the tropics in a shipping container.
I'm wondering if there is any reasonable way to un-warp parts that have warped in this way. Specifically, if I heat them up again, will they go back to their original shape, or will that just make it worse?
Here's a photo to show what the parts look like. The problem was a lot more obvious before I assembled it, but I didn't think to take a photo - here you can see that some of the edges aren't dead straight, but when they're not clipped to the other parts they're a lot worse. The edge of each triangle is a bit less than 20cm in length.

I'd really appreciate any tips. It'd be a shame if this project ended up not looking perfect after so much printing time.

PLA stays a thermoplastic in printed shape. And as you saw when unpacking your things, tropical heat and force are enough to get a lasting deformation. Other people had PLA prints ruined from having them sit in the car, I had seen deformation on a purple print I had let sit in the sun on an edge.
This also means that the reverse is true: under load to shape the part and some heat you can try to unbend parts. A hairdryer air of about 60-80 °C, which is more than enough to make PLA formable.

Thanks - I'd thought of trying that but wasn't sure if I'd just ruin the parts. I'm not sure if I should do it while it's assembled as in the photo, or try and make some kind of jig to get them absolutely straight and at the correct angles. Or maybe just hold them against a flat surface. I'll do some experimenting next weekend.

@Nathaniel Don't do anything with the assembled parts. Maybe you will deform some of them in other ways untill you get practice with undeforming procedure. And try make this with a jig. When they are hot, probably you will not be able to touch them long enough to straight them.

@mguima thanks, that's a good point - if I start blasting the whole thing with a hairdryer I could easily just mess it up. I'll think about how to build a jig, and be careful.

People here have unwarped prints within reason.  You just don't want to get so hot the print sags.  They would avoid heating areas that weren't warped.

@nathaniel I'm wondering if you would get better results heating the pieces with warm water 60° , it could allow a more uniform warming of the warped part than a hairdryer...and a pot with water gives  better thermal transfer than a blow of hot air just an idea. Good luck!

@mguima right, and I could put just one side of the triangle in the water without heating the other sides, maybe. I'll give it a go this weekend.


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Can I mix TMC drivers with A4988 on the same RAMPS board?
The closest thing I can find is this wiki page that state DRV8825 and A4988 can be mixed. However, the TMCs seem different, requiring more connections and offer more features, so I wonder if they can be used on the same RAMPS board with A4988, particularly for X and Y axis.

If you're going to use modern drivers with SPI or UART connections, you should probably invest in a board that supports them natively (SKR 1.3, 1.4; Fysetc F6, S6; MKS S GEN L) - it's a lot cleaner then compared to monstrous wire harnesses.
To use different drivers - and mix them - just define each driver as the correct type in your configuration.h file:
https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/Configuration.h#L687

Yes you can mix different drivers, including the TMC drivers (e.g. using for X and Y only).
How you do that is described in this instructable.

Please do note that, from observations, the 8-bit based Arduino boards and shields such as the RAMPS are becoming more or less obsolete; the 32-bit based controller boards are becoming mainstream. Such boards have a lot more potential in execution speed, memory and more available options for peripherals.


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What is the strongest filament type?
I'm looking for a filament that is strong, doesn't crack and doesn't break easily and is impact resistant. I'm currently using PLA and it's strong, but, I'm looking for something that doesn't snap or break when dropped.

It would help if you indicated what application you are considering. That will inform any recommendations.

"strong" does not mean much by itself and then you asked about cracking but also breaking when hit. The question is too broad and has no definite answer. Provide a specific use case, otherwise we cannot answer.

PEEK may well be the strongest filament out there (and it has other interesting properties to recommend it), but it is very difficult to print and requires a printer designed to operate at high temperatures. If you are still using PLA, your next port of call should be PETG. It is a lot stronger than PLA (although it will shatter if hit hard enough) and it is almost as easy to print. It also gives off hardly any fumes and it can be printed without an enclosure.

PLA (pure, not modified with softeners) is far stronger than PETG, especially layer bonding. The reasons for using PETG are heat resistance and resistance to deterioration from elements. Not strength.

@R..GitHubSTOPHELPINGICE the question is also about impact resistance and PETG is better than PLA for that. The problem is that the question is broad and poor...

ABS is less brittle compared to PLA.
Strength and impact resistance are not the same.  For the same Volume and Shape, I get more tensile strength (can apply a larger force without breaking) from steel than rubber.  I can however pound the rubber with a hammer many more times than the steel before I break it.
When it comes to impact (finite energy but potentially extremely large forces), general rule is: that which does not bend shall break.  Materials and shapes that can bend to help dissipate that energy will help against impact.  Outright strength, on the other hand, often is fairly rigid.
When I need both, I'll depend on a strength bearing part and a soft coating for impact.  Works for bony animals; works for parts.

PLA also gets more brittle as it absorbs moisture.


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Visible lines along Y-axis on Ender 3 Pro
I have a model that's placed on the bed exactly like on this picture:

I have constant quality degradation as the bed moves down to print in the upper left corner (1).
Everything is fine on the X (2)-(3) side. It does not have any visible artifacts. All hell goes along the (1)-(3) curve:

Top left corner (1):

On the way from (1) to (2) lines seem to disappear almost completely.
I used Cura slicer and these printing settings:

stock ender firmware
0.2 mm layer height
supports
2 bottom & top layers
PETG 235 °C nozzle
80 °C bed
walls x2
10 % infill gyroid
ironing
seam smart hiding
50 mm/s print speed
500 / 50 mm/s^2 acceleration / jerks

It looks like a mechanical issue, so I tried tightening/untightening bed bolts. It didn't help. They are a little bit tight, but not too much. The bed does not seem to be wobbling. Also, I tried the bed for wobbling in its top/bottom position. It looks fine along all the way.
What should I try next?
Extruder steps/mm are tweaked for this filament. Extruder produces exactly 97 mm of 100 mm of filament.
UPD
I decided to change my software/hardware settings step by step. This time I changed only my software settings to these:

Speed: 30 mm/s
Acceleration: 3000 mm/s^2
Retract: 4 mm
Combing: Not in Skin (previous print had the same value)
Overhanging wall speed 100% (same as the previous print)

Corners have become much sharper and there is a lot less of bulging on the arc.

However, by X-axis (2) - (3) I see more artifacts:

Y-axis has become better:

Currently, I don't have any visible or sensible bed / X play. I tuned rollers to have enough tension not to slip if rotate them separately. So, if I rotate the roller, it moves the whole bed or X carriage. I'll try increasing the tension a little bit and then I'll share the result.
UPD2
I've made belts a little bit tighter and decided to print a new model. The layer height is 0.3 mm. Also, I tried increasing temperature up to 240 °C and changed the stock vent with a circular vent. The wall count is 50 to make the model solid. Coasting is off.

Now all artifacts are along the X-axis. There are many fewer of them at (1) than at (2). The model is a doorstep. On the build plate it's placed like this:

Now I think the problem has nothing to do with X/Y play and these two factors can be eliminated. I'll revert belt tensions back to their previous values and decrease the printing temperature down to 225-230 °C.
PS. USBASP is still in customs, so I'm doing all this on the stock firmware.
UPD3
I have finally figured out what was wrong. It was insufficient Z-belt tension on both sides. A close look at a DSLR camera shot gave me a clue: there was almost always a straight segment followed by a visible additional step down between layers.
There are still some artifacts but everything looks relatively tolerable now.

Thanks to all of you guys!

On the Arc are retraction artifacts. What's your retraction setting?

@Trish, I have 6mm retract. I tried 2, 4, and decided to stop at 6mm. Otherwise, there was a lot of stringing.

There are a lot of different print quality problems going on here, but the biggest I see is the bulging and sagging at the corners of each layer. This is a result of extrusion not being a zero-delay linear function of extruder motor motion, but subject to compression/pressure. This causes excess extrusion when printing slows down (approaching and rounding a corner) and underextrusion just after speeding back up. There are several possible fixes:

Upgrade to firmware with Linear Advance and calibrate it for your material. I find PETG needs about K=1.4 on an Ender 3.

Increase your acceleration limits (up to 3000 mm/s² should be ok for Ender 3) so that far less time is spent moving slow. You need to adjust the per-axis limits in config menu, not just the single acceleration setting in your slicer.

Decrease your print speed so that there's less difference in cornering speed and nominal speed (50 mm/s is too high for PETG anyway in my experience; you'll get underextrusion and bad layer bonding).

Also make sure you don't have your slicer set to slowdown on overhangs, as it makes this phenomenon far worse.
The other surface artifacts I'm less sure about, and you should probably look for other answers about resolving them. Trish is right that the lines look like a retraction problem - material intended to be there got lost somewhere else. It's probably due to combing (skipping retraction inside the model and letting material ooze out there). I would set combing to "not in skin" and set the max combing distance to something very small (around or slightly less than 1 mm) and see if that fixes the problem. Combing is especially bad with PETG in my experience.

I see some possible issues at work here:

Retraction issues on the arc. You might need to decrease your retraction length a little.
Your bed might have a little play. tighten the eccentric nuts a tiny bit.
As you are at it, check your X-belt, because accuracy on the Y move is affected by the accuracy of the X-head's position.

authors: ครูต้นกล้า ครับผม


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Top Layer/Solid Infill Bulge
Whenever the print reaches a layer with top/solid infill, it bulges out. It is not on the same layer for every print, which rules out Z-binding. Here are things I have tried:

Different slicers
Updated firmware
Smaller K value for linear advance
Lower temperature
Slower walls and top layers
More perimeters
Tightened belts
Different filaments
Different jerk and acceleration values

My problem is similar to what these people are experiencing: https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-how-do-i-print-this-printing-help/buldge-when-print-reaches-solid-layers/
These pictures show my problem. The lip in the second picture is supposed to be parallel with the body of the model, not stick out to the right like in the picture.

Have you checked if the extruder is over-extruding? With infill there is room to bulge out inwards, but when solid if can only go outwards.

@0scar I calibrated my extruder and found I was actually under extruding a little bit.

I'm not sure about other slicers, but Cura has an option called Skin Overlap that defaults to 5% and causes excess material to be extruded beyond what actually fits in the skin (top/bottom "solid infill" surface) area. If you only have a few top layers it probably won't push the outer walls out and will just build up a rough top surface, but with more than a couple it's likely to start making the walls bulge out because there's nowhere else for the excess material to go. I've gotten dramatically better print quality since turning this setting off (0) and doing the same for Infill Overlap.

Unfortunately this didn't seem to fix anything. It was a good suggestion though. The fact that the problem persists between slicers suggests it is not a slicer issue, but it only happens around the transition from top/solid infill to the layers above it and not the same layer every print which is extremely confusing to me.

Can you view the sliced results and confirm that the bulge isn't actually there in the instructions to the printer?

Yes it's not there in the sliced preview or the model. Do you know of the XYZ cube model? When I print that, the bulges are around the top and bottom of the X and Y.

Maybe you have loose belts and the position of these lines varies by the slop in the belt depending on which direction the last move was from?

I just tightened the belts, but I'll try printing the test piece at a 45 degree angle.


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Minimum Solid Figure traced by a Delta 3D Printer
In Cartesian printers, the extruder is moving along the X axis, Y axis and/or Z axis. Every axes has its own resolution, this is the minimum length that is possible to achieve in that axis and is related with the number of steps that the stepper motors can do.

So, if we trace the solid figure with the minimum volume that the printer can achieve based on its axis resolutions we obtained some sort of a cuboid
The length of the cuboid in X is the resolution of the printer in the X axis, the same logic applies for Y axis and Z axis.
In the figure it is possible to see 27 (3x3x3) cuboids genarated:

if the resolution of the printer in X axis is 0.1 mm, in the Y axis: 0.1 mm and in the Z axis: 0.1 mm, the volume of these cuboids is going to be 0.1 mm x 0.1 mm x 0.1 mm
Now, consider a Delta printer:

What is the solid figure with the minimun volume that can be traced with it?

I think you misunderstand. It's the nozzle width and extruder step size, not the axis step sizes, that limit detail. Positioning resolution on a typical printer is on the order of 0.01 mm, but nozzle size is at least 0.1 mm and typically 0.4 mm. Also, lack of perfect rigidity in the mechanical parts will produce gradually increasing error as you try to go smaller and smaller in detail. So, it really makes no difference to the achievable detail whether the printer is a Cartesian or a Delta.

yes, I think you right, but either way, I think it would be interesting to see what is the minimum solid that can be created with the positioning resolution, just to use it as a theoretical model

You can work out the shape traced out by stepping each motor +- 1 with some math, but it's not translation-invariant; it will be shaped differently depending on where it's located. For this reason, assuming you want to be moving effectively in an XY plane to print layers, a delta printer really needs to have motor steps significantly smaller than the order of magnitude of the moves you're trying to produce.

In theory you could slice in the nonlinear space of the delta axes, but you'd effectively be doing "z-hops" to get around before the outer edges of your print built up to a level where the center of the build area was reachable, and it doesn't seem like a very practical or smart thing to do.

I want to work out the shape traced out by stepping each motor +- 1 with some math. But I don't have a Delta Printer and I don't understand how they work ..


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Some procedures to improve 1st layer
I'm wondering if anyone can confirm this improves the success rate of the first layer by doing this before starting print.  My case is using ABS with a Reprap.  In may work on other 3D printers and materials.

Heat up the bed and extruder to the starting temperature long enough to stabilize, so that the printer sets a more accurate z-height at the start.  While your printer may wait until temperatures are reached, it will usually start immediately without waiting.

After the extruder reaches starting temperature, wait until the filament material stops extruding from the extruder. Remove extruded material.  This reduces failures due to material extruding before the print, but after the start, ending up in the wrong place.

You don't get a more accurate Z height when you heat the printer and let it settle. You get a different value that will work perfectly. E.g. I've got printers that do bed leveling cold but print with the correct initial Z height to get a perfect first layer. This is also valid for manually trammed beds. The only settling you might need if for thick glass beds so that the heat can be spread evenly, but operating thick glass beds I've never had to settle the bed, just heat up and start. But since ABS is prone to shrink, heating the bed first and then the hotend might prove valuable, at the time the hotend reaches it's temperature, the bed had time to evenly distribute the heat.

Oozing isn't good, maybe retracting filament at the end of a print might stop oozing for the next print. Most higher end printers therefore have a purge/prime, wipe and retract procedure prior to printing.

Forgot to mention I also level the bed with the bed and extruder at temperature.


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Ender 5 pro , prints lean, but only when multiple parts are printed (almost)
I can print single, large, complex parts with multiple towers with long travels between them and nothing leans. So pretty sure it is not belt tension, lash, or slop.
When I add a second part to the build plate, there will be leaning. It starts leaning with the very first layers.
When I print the same parts one at a time and they do not lean.
(notable exception) If I add 2 parts to the plate, and then delete the first, and print just the second, it leans.
Any suggestions on how to move forward from here? I am stumped.

Could you add a picture, I'm not sure what is meant with leaning.

I have also found that the lean is affected by infill % A solid part Skews more than a hollow one. The solo part test prints all looked good because they were low infill, and adding a second part doubles the printed area AND THE SKEW. Adding a second part and using 100% infill makes a very stark difference. And the Enter key should not post the comment, it is meant as a CR LF, This is my opinion, not yours, though I am willing to share. Pressing the enter key here--->

Comments can not have more than one line, the Enter to end a comment is the intended behavior. You have 5 minutes to edit comments.

Thanks Trish. Still 100% my opinion that an enter key on a text box should not post. You don't need to share my opinion. ( Or my dry sense of humor)
Interface design is complicated and hard to implement well. Typing a sentence and having the enter key POST the sentence is (in my very uninformed opinion) counterintuitive and wrong.
One should be able to use white space...
It gives the writer more tools to express and accentuate ideas.

To accentuate, you can use code, italic or bold. You can even combine all. :-) Welcome to 3DPrinting.SE! Note that comments are used for other people to ask for clarifications, you then try to address that in the question. SE sites are not regular threaded message forums, just simple Q and A.


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X axis stops working sometimes on my Tronxy X5SA
This is regarding the circuit of my 3D printer Tronxy X5SA's stepper motor for X axis.
I had an observation: It has a cooling fan (40X10 24V) which is having issues lately - it stops working sometimes, and when pushed to rotate, spins back.
Problem: Now one of the stepper motors (NEMA 17 ~3.5kgfcm) in my core XY has been malfunctioning, where it misses rotation sometimes out of the blue, which shifts the whole print. I thought this is due to the driver limiting the current to the motor, so I rotated the screw terminal clockwise a bit more to allow more current for the motor. This works fine for a while, but the problem comes back.
Now, I also noticed a few times that this issue occurred when the cooling fan for the drivers stopped working.
Can the stopping of the cooling fan cause the stepper motor to falter?
Another observation is that the stepper motor which is faltering is placed close to another stepper motor. Although I know stepper motors can work in extreme conditions, can this cause the issue?
If you require any more info to investigate the issue, please do let me know

I have exactly the same problem. Rising voltage helps at some degree. I mean the voltage of power supply.

Yes, if the stepper motor drivers overheat, they shut down or skip steps, that is very possibly related to the failing stepper driver cooling fans.

Thanks, it turned out that was the case. I cleaned the fan thoroughly so it was running at full speed (I could say by the improvement in air flow), and now the problem is solved

It might be cross-talk with back-EMF from the fan confusing the stepper-motor driver. Do the cables run together, and have you tried separating them?

authors: تصنيف للاعتماد


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Z-offset issues with Slic3r and Da Vinci Nano
I was attempting to use Slic3r 1.3.0 to print to my Da Vinci Nano, using MiniMover (a replacement for xyzprint) to load the G-code.
The print seemed to be a couple of millimeters off of the bed, but adding neither 2 or -2 offset in Slic3r worked.
Neither did adding the following to the g-code.
G92 Z2
G0 Z0

Anyone have a solution?
The start of my G-code is:
; generated by Slic3r 1.3.0-dev on 2020-06-28 at 10:37:50

; external perimeters extrusion width = 0.55mm (3.04mm^3/s)
; perimeters extrusion width = 0.70mm (7.88mm^3/s)
; infill extrusion width = 0.62mm (9.31mm^3/s)
; solid infill extrusion width = 0.70mm (2.63mm^3/s)
; top infill extrusion width = 0.70mm (1.97mm^3/s)

M107 ; disable fan
M104 S220 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle

; Filament gcode

M109 S220 ; set temperature and wait for it to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0 ; reset extrusion distance
G1 Z0.300 F7800.000 ; move to next layer (0)
G1 E-2.00000 F2400.00000 ; retract extruder 0
G92 E0 ; reset extrusion distance
G1 X40.004 Y40.786 Z0.300 F7800.000 ; move to first skirt point
G1 E2.00000 F2400.00000 ; unretract extruder 0
G1 F1800
G1 X41.753 Y39.328 Z0.300 E2.46602 ; skirt
G1 X45.000 Y38.464 Z0.300 E3.15334 ; skirt
G1 X75.000 Y38.464 Z0.300 E9.29109 ; skirt
G1 X77.243 Y38.861 Z0.300 E9.75711 ; skirt

Behavioral analysis
To find out what is actually wrong, let's do a simple series of test commands first: a G-code that homes the printhead, moves it up 100 mm (10 cm), then zeroes there, moves up 20 more and back to the new 0 at 100 mm above the bed. Make sure not a single offset is active anywhere when sending/loading the G-code as this is to test for the actual movement.
G28
G1 Z100
G92 Z0
G90
G1 Z20
G1 Z0

Measuring the distance to the bed should give us something hopefully close to 100 mm. If it is longer or shorter, we have a problem with the bed position to the endstop, even if the bed itself is level to the machine. A releveling is advised unless there is a reason to home to a position widely outside of the printing height or if leveling proves to be impossible.
Why is the error experienced?!
The culprit seems to be that the Z-offset parameter in slic3r is not updated properly when altering it. I just tested this with a ludicrous offset and it took several saving and slicing attempts to register that Z0 was supposed to be 200 mm over the endstop via the offset setting. Compare these two blocks:
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z0.350 F7800.000

And this one:
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0
G1 Z-199.650 F7800.000

The offset only appears factored in starting with the actual print's G1 commands. But how did I eventually manage to make it update?
Forcing the update
To force an update of all the settings, I did create a secondary printer profile (just saved the same one and in the new one set the offset back to 0) and then swapped between the two back and forth twice and then the correct offset one. This seems to be a very reliable way to force an update of this setting, as it did register every swap after the first one.
Workarounds
manual Offsetting via Filament parameter
But there is a way around that is always taken into account: we can add a custom Filament Start Code, which contains the needed offset under Filament Settings tab > Custom G-Code:
G1 Z<offset we need to be exactly at layer 0 height>
G92 Z0.3

But this is a rather clumsy way and should only be made if nothing else helps and not in conjunction with any offset in the machine setting!
Tackle the problem by the root
The problem isn't usually the offset but a bed leveled to the wrong height. To level the bed the printer should be brought to Z0 via G28 and then leveled again. If this proves futile, setting the offset and forcing an update in slic3r is needed.