text:
Is resin printing correct for my needs & limitations?
I'm considering buying my first 3D printer. The only place in my house where I have enough space is the garage, and I fear a PLA printer will suffer from the possible temperature differences I may have there.
For this reason (And also the fact that it seems smoother) i'm considering buying a resin printer (like the Elegoo Mars), but I wanted to know if the fact it will be in a garage could be a bad idea? I imagine resin printing is far less sensible to temperature variations, but I may be wrong.
I will only print as a hobby, probably some figurines for me and my kids to paint, or small hardware pieces / boxes for electronic components.

I'm considering the same thing. I eagerly await responses.

Resin likes it warm and dark
Resins increase in viscosity at low temperatures, so having low temperatures may have bad effects on the prints. However, Resin also likes it dark, so if your garage has a temperature above about 10 °C and is dry enough to prevent condensation, then your garage would be a good place.
Figurines and high detail models are a common use case for resin
It is near impossible to print miniatures for wargaming and similar in FDM, but resin printers are a very common type for this use case. Similarly, Cosplay props with a very high detail grade can benefit from being printed in resin, either directly or as an intermediate step to create a mold.
With the proper equipment, one could make flexible molds to cast wax positives which then can be used with the lost-wax-technique to create many high detailed metal copies of the printed first positive.
Containers are a possible use case for resin
Resin prints are more brittle than FDM prints. While limited in size, such containers, just as much as casings for electronics, are a possible usecase. In fact, replacement casings for retro electronics (think SNES controllers or N64 Cartridges during restoration projects) are somewhat common, even though they have not the same sturdiness as the original ABS casings. Here, the high detail grade makes the cut.
Tooling is a poor use case
Resin prints are very brittle and have little to no ductile movement. While I have used FDM-printed parts from PLA in a few projects to make adapters between machines and my shop vacuum as well as to create an aluminium bending tool, resin printed parts with their near to no flexibility are generally a poor use case to create hardware or tooling from.

Thanks for all the info! I should check the current temperature in the garage, to see if I would be able to print during the winter.

I just checked, the temperature is currently just above 12 degrees. It should be perfect then.

@MarcBrillault 10 is the absolute minimum, but you might want to take precautions against condensation nontheless.


text:
Converting .print file to STL
Hi I am trying to obtain the STL for the automatically generated support structure for a part that has been 3D printed, is there any way of doing this from the GrabCAD .print file? Or any work-arounds?

STL files represent solid objects as triangles covering a surface.
Most support structures are not solid objects, but thin walls whose size depends on the diameter of your nozzle, and in some cases, calling them walls is generous.
Support structure is usually generated at the slicer level, which generates images of layers or gcode tool paths, and it does not make sense to translate that back into an STL.

however, one can do so, in fact, prusaslicer allows to export with the support structure - usually this is used to offer presupported STLs for resin models.

source: Stack Exchange

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

sort: votes


text:
Advanced Delta Printer Calibration Question
Specs:
Printer Configuration: Delta
Firmware: Marlin 2.x
Probe: Conductive nozzle (Verified repeatable 0.01 mm accuracy)
I'm working on calibrating my delta printer to 0.01 mm +/- 0.02 accuracy. Every guide I see either says "run G33 that should be good enough" (news flash it isn't lol) or they reference this Advanced Delta Calibration tool.
Which relies on your filament/nozzle diameter/flow rate/temperature to all be exactly precise (which isn't physically possible if we're talking about differences small enough to affect dimension calculations in some way).
I'm essentially looking for a precision tuning guide for a "delta robot with a probe" rather than one for a "delta 3D printer". Does a guide like this exist?
If not, maybe you guys have calculations that may help. Right now I'm working on tower angles and individual rod offsets using this script.
It probes towers and opposite towers in the order of: Z-ZY-Y-YX-X-XZ-Center.
With a loosely leveled bed (+/- 0.05 mm @ towers) and a G33 P2 I get probe values:
Z: -0.08
ZY: -0.21
Y: -0.01
YX 0.23
X: 0.02
XZ: -0.66
C: 0.01
Which is essentially a "tilted pringle" shape which can be visualized here with this input.
Just wondering what to do about inaccuracies in the diagonals. Is there a formula for tower angle/rod length based on probe points? And if not is there a more accurate way of doing this that doesn't involve printing something?

I designed and built both a full Stewart platform, 6-dof router, and a "delta" style, constrained Stewart platform 3D printer with 3-dof.
For the 6-dof machine, I postulated a set of error variables and used simulated annealing to find a good estimate of the error values.  Those error values were inputs to the kinematics and gave much better results.
For the 3-dof machine, I found it difficult to calibrate love the whole 18" diameter print bed, and decided that a real fit may not be worth the trouble.  Instead, I mapped the surface using a probe, and fit an error function to that data.
After trying a few methods of measuring the bed surface,  I settled on using a strain gauge to measure nozzle contact.  I had tried electrical contact, IR parallax sensors, and inductive sensors, but all had unfortunate ways to give bad measurements.  A strain gauge worked better, although it, too, is subject to problems if there is debris on the bed, or plastic that flows through the nozzle.
When I make my next set of changes to the 3-dof delta 3D printer, given the superior sensing of the strain gauge, I may go back to a scheme of estimating error variables.
There are a lot of potential errors, all of which affect a delta machine's ability to know where the Z=0 cartesian plane lies.  Any positioning error of the joints, any error in the spacing between joints, any racking of the printer structure, and any non-orthogonal-to-the-bed movements of the top joints will give you various compound cup and disk errors.  Even the uncertainty of the home sensors adds an expected curved error to what should be the Z=0 cartesian plane.
My experience has been that the most important thing in 3D printing -- knowing exactly where the bed is and maintaining a uniform height for the first layer -- is the hardest thing to get right with a delta machine.

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


text:
OpenSCAD can't render union of two polyhedrons, but can preview just fine
I am running into what honestly seems like a bug in OpenSCAD, but I can't believe that something so simple could reveal a bug. I am trying to render the following code:
module tri_prism(base1, base2) {
    polyhedron([
        base1[0], base1[1], base1[2],
        base2[0], base2[1], base2[2]],
        [[0,1,2],[3,4,5],
        [0,1,4,3],[1,2,5,4],[2,0,3,5]],
        convexity=5);
}

union() {
    tri_prism(
        [[0,0,0],[0,1,0],[1,0,0]],
        [[0,0,1],[0,1,1],[1,0,1]]);
    tri_prism(
        [[2,1,0],[2,0,0],[1,1,0]],
        [[2,1,1],[2,0,1],[1,1,1]]);
}

This should render two (non-overlapping) triangular prisms, like so:

However, this image is only the preview. When I hit F6, it renders this, with only the triangular bases being rendered:

And the console shows this warning, which I don't know the meaning of because I am a beginner:
UI-WARNING: Object may not be a valid 2-manifold and may need repair!

Each of the prisms individually renders just fine, but the two of them together don't. Also, it is not merely a problem of appearance since exporting it as STL and opening it in Cura, I see the same useless nonsense.
Is this a bug or am I doing something wrong? And if it is a bug, how do I work around it?

If you are opening these files in Cura, then presumably you are going to (eventually) 3D print them, once you have fixed the issue described in your question?

This is a case of "Mis-ordered faces".
That means the order in which the vertices making up one or more faces aren't in the correct order.
The vertices of a face should be listed in clockwise order from the perspective of a camera looking at the face form the exterior of the polyhedron.
In this case, the problem can be solved by reordering the [0,1,2] face of the tri_prism polyhedron as, for example, [0,2,1].
The misordered face(s) can be found by enabling the Thrown Together option from the View menu and Previewing. The faces in question will be shown in magenta.
Why, then, if the faces are mis-ordered, did the prisms render just fine individually? My guess is that faces have to be properly ordered to be sure to get a correct Render. The behavior of Render is simply indeterminate for polyhedra with misordered faces. It can work in some situations, but it's not guaranteed.
Edit: I forgot to add that, in my opinion, this shouldn't be an issue, and that if it's such a big problem for the Rendering subroutine, it should intelligently reorder the mis-ordered faces in a prelude. It would avoid beginners such needless troubles.


text:
Issues with layer changes/z-seam
I have a Creality cr-10 printer. Everything is stock except for the direct drive extrusion system (I bought a conversion kit from Micro Swiss).
I have been working to dial in my settings, and I think they are almost there, with a few exceptions. There seems to be roughness/blobs at the layer transitions on my prints. This was present before my conversion to the direct drive system as well. I calibrated the steps/mm after the change as well. What settings should I focus on to try to get rid of this? Or is it some sort of mechanical issue? I've included some example pictures:

From your pictures, the blobs are (at least mostly) not at layer changes but at speed changes where the toolhead has to drastically slow down and speed back up to go around a sharp corner (including as a special case a corner in the Z direction, i.e. a layer change). This happens because, when the toolhead slows down, there is still pressure in the nozzle due to forces that cause the plastic to resist being extruded to a degree that scales with the speed of extrusion.
The right solution to this problem is enabling and calibrating Linear Advance, which directly models and compensates for the phenomenon. Unfortunately, most printers including yours are still shipping with firmware too old to have this feature, or built without including it. So, your options are:

Update to firmware with linear advance and calibrate it. The factor for PLA on a direct drive is likely to be around 0.04-0.06. This is the best solution but might be unnerving if you're not comfortable with making that kind of change to your printer.

Print at lower speeds, so that there's less difference between the cruise speed and the speed at/near the corners.

Print at higher acceleration/jerk, so that the decel/accel cycle at corners happens much faster giving less time for the residual pressure to push out more material.

Some of the issues in your pictures, however, look similar to "blobs" but apppear to be warping/curling from insufficient cooling or excess bed temperature. These are the ones in the first few mm of the print, below the lettering on the back (the lettering clearly has actual blobs). Using a lower bed temperature or even unheated bed, and/or improving your cooling (replacing the part cooling fan with a larger one, or pointing a desk fan at the printer during printing) should make these issues go away. You can probably also avoid it by printing significantly slower, or possibly by reconfiguring your slicer to print the outer wall first, before inner walls.

Lots of stuff to try, thanks. I'll certainly lower my bed temp, and I've heard of people having success using 3D printed fan ducts to deliver more airflow directly to the nozzle. I think I've underestimated the importance of cooling. I'm certainly open to updating my firmware and messing with the Linear Advance setting, sounds like it might be exactly what I need. It might take a while, but I'll report back with what happens!

I updated my printer firmware to Marlin 2.0, enabled linear advance, and calibrated. I printed another Benchy and it looks worlds better. Much finer detail at edges. Still some blobs, but I agree that some of that is probably from insufficient cooling.

@Nick: Great to hear it helped!


text:
New Ender 3 Pro Thermal Runaway
I just assembled my Ender 3 last night, this is my first printer and I’m new to this all. After about 10-15 minutes into printing it consistently gives me a thermal runaway error. Any help would be appreciated.
The (part cooling) fan is spinning.

Photo of the machine please?

Thermal runaway occurs when the hotend is on, but the sensor does not pickup any temperature increase. In many cases the thermistor is broken or the connection is bad.
A friend of mine had the thermistor broken on his Ender 3 pro. It worked sometimes and sometimes not. Buy a new thermistor.(a few $ only) and replace it to be sure.


text:
Ender 3 doesn't extrude enough?
I tried printing something after 7 weeks of not using the printer (before it worked greatly) and I think it doesn't extrude properly (although I'm not sure about it).
When I tell the printer to extrude filament it works just fine, but during the print there seems to be a problem with it (see image below). When manually pushing the filament with some force, it works for a bit, but stops working after 1 minute.
I tried cleaning the gear, levelling and cleaning the bed with almost no success.
I'm using a Creality Ender 3 with a (golden) PLA filament.
This is how the print error looks like. The first layer should be completely filled.

Note: I didn't change anything (neither the filament nor the software) and before it was printing fine with 200 °C.

Assuming nothing has changed on the software/slicing side, either your extruder is malfunctioning/broken or your hotend is jamming.

HI & a warm welcome to SE.3DP. If you up the temperature and it fixes the issue, then please just accept HandyHowie's answer - using the tick icon/button. You could add in a comment under HandyHowie's answer what temperature actually worked for you, I guess. However, comments are generally ephemeral in nature and tend to get deleted. If you have additional information (relating to the question rather than the solution), then it should be added to the question and not put in the comments. Comments are generally used for us to solicit more information from you, for you to add to the question.

I would first check that your nozzle temperature is correct for the PLA you are using.  If it is correct, try increasing it 5-10 °C.  I experienced an identical issue and found that it was an incorrect nozzle temperature.

Also consider that the nozzle temperature and nozzle travel speed are interrelated. If you have an excessive movement speed with "normal" nozzle temperatures, the filament might not melt fast enough to be extruded.

This is not a temperature issue unless the OP has the temp set to like 160 or so.

@R..GitHubSTOPHELPINGICE I am just speaking from my experience.  My PLA needed 210 to work well, but the printer was set to 200 and was doing the same thing.  The bed had been checked several times.

This has happened to me before. As suggested in another answer by @HandyHowie I would try to increase the nozzle temp. PLA usually requires around 190-210 °C however I have found this usually varies from PLA type. I would try using something like 230 °C as this seems to work for me.
Another issue could be with your slicer. It could mean that the slicer isn't correctly slicing the model and this is a result of it. I would try using a different slicer as well.
Finally, if this is a model developed by you or another person, there is a chance that it hasn't been exported correctly. If all else fails I would let the printer continue running.
From your image, it appears that it has only just started putting down the first layer. Sometimes my printer does this but goes and fills the holes in later on in the print.


text:
How Do I Determine The Appropriate Magnet Strength For A Tight Seal On A Box
I want to use magnets to hold the lid of a box down tight enough to keep it relatively airtight (along with a rubber seal etc.), but I am not sure what strength of magnet to use, that will still allow it to be opened without causing damage either by having to be pried open or by crushing the print layers. I cannot seem to find any guide to how magnets are used for 3d printing at various strengths and I cannot afford to buy too many types that I am not then going to use.
Any help that you can provide will be greatly appreciated.

This sounds more like an engineering/physics question than a problem with 3D printing. Please clarify the 3D printing problem you are having.

I thought that someone with more experience with magnets and 3d printing could clarify things like magnet strength to part strength/infill etc.

This looks like an appropriate 3d printing question to me.  3d printed parts need vitamins sometimes.

You can vary the “strength” of the magnet by making a membrane of 3D printed plastic in between the magnets. The strength of the attraction is something like a logarithmic relationship to distance- small changes in thickness of material in between the magnets have a large effect on how strong they stick to each other. You could dial in your print by buying strong rare earth magnets and experimenting with attenuating the strength with the membrane. Could even use sheets of paper to get the right feel, then measure the thickness of the stack.
If using an fdm printer, it could be helpful to insert the magnets with a pause in the printing, and print over the top, if there isn’t a good way to otherwise capture them.

I had a similar experience using magnets to hold two plates together. Currently also building a device (3d-printed) that clamps together with magnets. For both of these scenarios, I typically start by looking at what size and force you need. I would look into maybe 3 options of different magnets to start with. It could be in the range of 0.6 lbs, 4lbs and 6lbs. Do you know how much the "opening force" would be? As in what would keep it opening? If its substantial, I could see more the 6lbs but this is a very very very rough estimate that honestly would be best supported with trying a few ranges of magnets first. Try McMasterCarr if you're in the US. They have affordable sized magnets that I've worked with, ranging from different sizes, thicknesses and magnetic forces.


text:
What cause the pattern in a large area?
Every time I print a large area I get the pattern in the middle.

Below picture was taken during printing. The material isn't evenly laid flat on the bed and some are being scraped up.
It appears from some centimeters away from the edge and extends perpendicular to the nozzle moving direction.

The pattern appears at the similar position when I print the same model again.
It's a delta printer. Print PETG on glass bed at 75 °C.
Update:
After adjusting delta height to add clearance, the first layer is super clean without any wave.

This has been asked before, this is the start of the effect, with even closer nozzle to gap (paper distance) you might run into having waves in the first layer. This is caused by too much flow in too less space, increase the nozzle to bed distance for Z=0.

Have you tried lowering the print-head travel speed?  Do the "blobs" get shorter?

The wavy lay down on the first layer usually indicates one of two problems:

The first layer is badly calibrated (too much distance, laying down in waves or too little, squeezing out in waves).
The plastic doesn't stick to the bed well enough.

Thanks. Adding clearance solved the first layer issue. But there is still top layer quality issue on top layer. Please read my update.

Top layer is a different question from bottom

Yes I searched and found the top layer issue may be caused by Marlin firmware configuration. Removed from my question.


text:
Creality Ender 5 Pro stops working
I bought the Creality Ender 5 Pro 29th of December 2021, so it's pretty new.
I have done about a hundred prints by now, without any problems, it's a damn good workhorse... until last Friday.
The printer stopped after making the brim, just full stop, the board didn't respond so I had to turn the printer off and on. I tried to resume the print but it stopped working right away, after that I turned it off and on again, and send it to auto home, that just works fine. Restarted the same but new print, and everything stopped working at the same spot again. Turned on some other prints, same thing stopped working after the brim.
At this point, I decided to check out the hotend, filament, etc. I couldn't do much with the hotend as the nozzle was fully stuck, unable to remove, so I bought a full new hotend set. It didn't solve the problem, even with the new hotend it stops after printing the brim. So I tried different slicers, again, no difference. Cura/Creality/Prusa slicers, nothing works.
I tried changing the settings of the prints, but nothing worked either.
I did notice that the printer stops at the same point, which is almost right in the middle of the bed.
I have a new bed, a PEI bed, which is not deformed it has no bumps.
I did not do anything with the programming, I also did not change the motherboard. The bed is perfectly level. The filament doesn't seem to be a problem either after using up 3 kilos already without problems.
So to remove some things that ain't the problem:

the bed is not the problem
slicer program is not the problem
hotend is not the problem
bed level is not the problem

So there are 2 things left (what I know about).

the SD card
motherboard/software

If anybody knows what the problem might be, or what else I can do to fix it, please let me know. I'm starting to run out of ideas that I myself can fix.
The prints I have tried are different models (STL file) and different slicers are used.
I made a new model, a simple 2 cm by 2 cm by 3 mm square, it stops after the brim.
I tried the prefab dog model that is on the SD card, without a brim, and it stops around the same time/spot, the only difference is that it keeps pushing out filament which does not happen with the self-made models.
I also found out that it happens at all places, there is no difference in printing in the left corner, or in the middle of the bed.
I unplugged all the cables and connectors and reconnected them again, I removed the hotend and attached it again, so that it is perfectly lined up.
A video of the problem: https://www.loom.com/share/d58e7e1db719480f81b765e83988e9e4?fbclid=IwAR2GT0MA2VtEO7TpB2jx9Km5Kf4sJkD5W3CYHjAgFbf51fGrWaoGm-_9MSU

It actually doesn't stop after the brim, it stops during the first layer of the object. Please provide a link to your source G-code e.g. using PasteBin. It is a long shot considering you used different slicers.

Hey, have you solved this problem yet?

To fix the Ender 3 not printing or starting, you need to reflash the firmware to rule out any errors, calibrate your hot end temperature with PID Tuning, and check your filament if it has snapped from somewhere. The Ender 3 also won't print if the nozzle is too close to the print bed or the nozzle has been clogged.

Please note that the question is about an Ender 5, not 3. Firmware shouldn't be a problem, the printer worked for hundreds of prints.


text:
Print not fully connected to edge of frame
I tried printing this mesh sheet, but the mesh part doesn't connect with the edge on one side. I have no idea what would be causing this. Is it something with the model? Is there a setting I can change in my slicer? Any help on this would be greatly appreciated!
This is the model that I am using: 3D Printed Mesh Sheet
I'm printing with PLA on a Voxelab Aquila printer, and using Cura as my slicer.
As you can see, the mesh is not connected to the edge of the print:


text:
What parts are compatible with the Anycubic Mega Zero? (FNG here)
I bought a 3D printer 2nd hand from someone a year and a half ago and finally set it up last week (I know I'm terrible). It's an Anycubic Mega Zero. I'm pretty sure it's the first version not the 2.0 as it doesn't have a hotbed. My question is what aftermarket parts are compatible (preferably plug and play) with it?
I've searched the name and model and am not coming up with a straight answer. Is there a specific model or "type" I should look for to know it will be compatible? Or a place that's a good site to work off of other than Amazon that maybe they actually know when I ask a question?.
I'm mainly concerned with parts that I can just plug in and go with minimal setup or very good directions explained well. Feel free to add more advanced options also for consideration later such as dual head extruders and maybe an explanation on how to modify firmware (links if available).

Hi Matthew, welcome to 3DPrinting.SE! What is FNG? Please explain if I'm missing something. Furthermore, the question is very vague. Which parts do you want to replace, or are there parts missing? Please add an image if so. Possible upgrades and options cause endless discussion and the world of answers. Please be specific what you want to replace and why. See What types of questions should I avoid asking?.

Save the question by posting an image of the printer to aid in the selection of the correct printer name and type. Be specific with what you want to buy new. Or e.g. if you want to upgrade to a heated bed.

hey oscar thanks for the reply FNG is a slang term we use in my part of the US that in the nicest terms means freaking new guy lol and as far as specifics i think i would like a better hotend and a heated bed and maybe a better extruder ive seen dual z axis lead screws any input on the usefulness of that? like i said im super new some im just now figuring things out and im not even sure what the model is for my hotend but i did find some articles a minute ago that had some info on upgrading the hotend with some 3d printed parts so that maybe the way i go but first i gotta get nozzles and im

not really sure which ones to buy besides in terms of the end that screws into the hotend itself


text:
Swapping magnitized bed plates?
I print a lot of stuff, and I was thinking I could get several magnetic bed-plates and when 1 print is done simply have my wife pull the plate off and stick on clean plate and start the print again.
But a friend of mine says that won't work. Because even if the plates are made by the same manufacturer you can't guarantee the bed will be level. 〰
Has anyone ever tried this?

Hi MattR, welcome to 3DPrinting.SE! If you have a Z-sensor instead of a Z-switch you could add a G29 before each print, if the idea is to change the plate while you are not at home and somebody less experienced need to do some tasks, that could be a solution. The crux is what kind of printer you have, please expand the question by [edit]!

try it and if you have 1st layer issues consider a raft support.

It is a question of quality:
You better make sure that your plates are the same thickness evenly, and level very similarly. If that can be assured, they can be swapped easily.
In case you have a bed leveling sensor of some sort, you might include a whole bed-leveling cycle in front of every print and exchange between numerous beds, even of slightly variant thicknesses and with dings.

Yes ,I was also facing the same problem couples of month ago and to solution I had buyed extra plates and It works perfectly . Go for the extra beds and buy only from the same manufacturer.
Hope your get your answer


text:
Adventurer 3 Not loading Filament/Grinding Sound
Have had my second Adventurer 3 now about 3 weeks.  Used all of the red filament that comes with it but when I go to load new FlashForge filament in the unit, I can't even get it to suck up the filament.  I just get a grinding sound like something is majorly wrong.  Any ideas please?  The filament will not even make it to the extruder.

Try making sure there is a clean cut on the end. No fraying or angle. A straight clean cut. Then when loading push it a little. Give the filament a little help. It's worked for me.


text:
Are "matte PLA" filaments abrasive?
I picked up a roll of Overture matte black PLA, and the surface of both the filament and the printed object feel like paper. This made me wonder if it contains wood-based fibers like "wood PLA" does, and if so, whether it's abrasive and harmful to the nozzle. In the past I wouldn't have cared, but I'm using a CHT now and would like to avoid ruining it since it's expensive and I don't have spares sitting around.

You may be experiencing the feel of paper, which is typically a matte surface, when feel testing the printed item, as both would be matte. A search for your focus found one purchaser of this product (via Amazon) has left an answer addressing this question. The answer is on the last page of Q/A and is accompanied by another answer suggesting the white filament is abrasive. One has to click "see 2 more answers" in order to locate the quoted answer.
His reply was that he has printed 8 spools and found no deterioration of his nozzle.

Not any more than any other PLA. I've gone through 8 rolls of this PLA so
far with no noticeable degradation of my nozzle. D. DAmico · September
30, 2021

My own suspicion is that the filament has a chemical additive to create the matte finish, rather than any particulate that might cause abrasion.

This answer would be great with a link to the review (and quotation of the relevant part). There are so many I can't find it.

Since then I've found (and lost) some other reviews where folks claimed, with photos supposedly providing evidence, that matte PLA did destroy their nozzles. So I think this topic is still open...

At least one filament manufacturer, Protopasta, documents their "matte fiber HTPLA" as "containing plant fibers" but also documents that

Matte Fiber does NOT require a wear resistant nozzle.

So I think fred_dot_u's suspicion that the finish is produced by a chemical additive is probably false; it looks like these finishes are created with something similar to wood, but softer than brass so that it's non-abrasive.
This also suggests that matte finish filaments (at least the ones that feel paper-like) might have additional benefits beyond cosmetic, such as the fibers helping to resist warping while the extruded material is cooling, which seems to match my experience using it (less sensitive to cooling performance than normal PLA).


text:
Stock hot end for Anycubic Mega Zero 1.0?
Does anyone know what hotend the Anycubic Mega Zero uses? I've found info on upgrading to a different one but I'm thinking of just buying more nozzles for now and trying other options later. I'm not sure if I'm looking at the right things when I did a Google search. The hotend I'm looking at looks like an MK8 or even a Mini Swiss but I've read it's a J-Head? Am I missing something?

The picture you have shared leads me to believe that it is an MK10 style hot end (Sometimes erroneously referred to as a Creality-style hot end)
MK10 is identified by its 'Flattened' heat sink shape with screw holes through the heat sink for mounting, Along with the smooth, un-threaded geometry of the heat break entering into the heat sink.
MK8 is similar, Consisting of the same Flattened, screw-mount heat sink design. However, the MK8 hot ends use a threaded heat break on both sides, rather than only on the heater block side.


text:
MKS-SBASE V1.3 Marlin Stepper Motor Current
I have an MKS-SBASE V1.3 with integrated stepper motor drivers, but they don't have a physical way to change the current. I know there is a way to update the DRV8825 stepper current through Marlin, but I can't find it. Is it located in the advance configuration tab, or is a G-code I need to use?

MKS makes inferior products. Beware that Smoothieware has released a statement why MKS hardware users should ask MKS support first.

From "WHAT IS WRONG WITH MKS ?":

They use DRV8825 stepper drivers which are much more prone to loosing steps than Allegro or Trinamic drivers

DRV8825 driver current cannot be changed from firmware like e.g. Marlin, Trinamic drivers can, but they are not installed on the board.

The MKS SBASE 1.3 has a potentiometer to set the current of each of the stepper drivers.
Don't see a physical potentiometer? That's correct! There are electronic potentiometers on the board. If you're using stock firmware: I can't tell you how to change it, but it must be possible. I'm using klipper and it has a section that by default sets the current to 1.0 A.

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.


text:
What causes inconsistency of sizes?
I printed this hook that must have 2.8 mm thickness of all walls:

But actual sizes differs:

And I think this is a reason why the 3.0 mm wall has a gap.
Printed with Monoprice Select Mini v2, nozzle 0.4 mm, PLA at 210 °C, PrusaSlicer.
This issue isn't a casual fault, I printed the model several times and always have exactly the same issue.
What causes this inconsistency of sizes?
UPDATE. Thanks to Oscar's comment:

It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.

Indeed, after rotating the model 45° I've get almost perfect print with almost perfect sizes of all walls.
Maybe I'm wrong, but I believe this is because of non-ideality of printer's mechanics and lots of paths parallel to X or Y axis in the model. For example, when the printer prints a path parallel to X, then Y axis is fixed. Then, to print an adjacent path, Y moved a little (= extrusion width), and because of non-ideality of Y mechanics, there's some error here. By placing the model such way that minimizes the paths when X or Y axis is fixed, it eliminates such defects by averaging the error.

How dimensionally accurate is your printer? Have you calibrated your 3D printer? How long ago? If you need more info see What prints can I do to test/calibrate my printer for precision?

@agarza: I never calibrate it, but you can see that some sizes are exactly the same as in the model, but some other differs. I think all sizes would changed if the problem was in the calibration.

Calibration for one axis will not automatically calibrate another. I do find it interesting that both of the horizontal members are different sizes; the same as the vertical ones.

It is a budget cantilever printer, try if orientation of the part makes a difference. E.g. rotate the object 45 or -45° on the build plate by re-slicing.

Slop in the relevant belt looks like the most plausible cause.


text:
Nozzle not level and first print failed
So I just got my first 3D printer the Ender 3 Pro. My nozzle is a bit too high (first image) and this is what happened after my first test print (second image).
I saved for a while to buy this and I’m really upset about this.

Have you checked to make sure that the Z endstop is properly positioned according to the assembly instructions?

I’m pretty sure it’s in correctly. I added 2 pictures of it to the post (should I remove the green oil or whatever it is?)

The Z endstop (or limit switch) is in your first photo on the left-hand side. It is attached to the outside of the vertical rail. If that is not set properly the nozzle will be too high off the bed.

Sorry for the dumb questions but how do you mean “properly”?

The Z endstop should be positioned so that when the nozzle is just touching the build plate the limit switch is triggered. It may take a bit to align correctly. Also make sure that the Z endstop does not rotate when you tighten the screws; this can effect the nozzle height.

Hi, welcome to 3DPrinting.SE! Don't be upset, it is s minor issue that is easily fixed! Note, the title "Nozzle too far from bed, prints fail" might be a better description of your problem?.The current title hints to an unlevel/untrammed bed, while the issue is an overall offset. You can [edit] your question!  Read my answer below and the link to the article, you should be up and running in a jiffy!

Hi. I followed what you said in your answer and the article but it’s still too high. Read my comments on the answer for more detail

unrelated to your problem, but you might want to remove the excess grease from the screw.

Your Z-endstop assembly is clearly too high. Referring to your own first foto you see that the switch on the Z-endstop mount is nearly touching the bottom of the X-Z mounting.

You need to adjust the whole mount by loosening the 2 hex key screws and lower the assembly (move in the direction of the blue arrow):

Source: Larry Wood via All3DP
Before lowering the Z-endstop mount first screw in all the levelling/tramming screws under the build plate/heated bef a little and position the nozzle a little above the build plate; when the mount is fastened you can move the build plate up a little and tram the complete bed surface.

This All3D article describes the above in more detail, but the basics are covered above.

I did all this and when I auto home, the Z still stops well above the print bed like a whole 5 mm. I even tried manually adjusting the Z-axis and setting home and then auto home but it still stops high above the bed. I also try raising the bed but the knobs become so loose they fall off.

@desperrrr Then you are maybe mistakingly doing something wrong? This is the way to get the nozzle to the build plate level. Maybe you can edit your question with more specifics, e.g. describe in steps what you do, and add a photo where Z=0. Note that after homing the nozzle is always raised, so be sure to guide it to Z=0.

Flash the firmware. If that doesn't fix it then you have a defective printer assuming everything else in your question and comments is correct.

Could you [edit] and expand your answer? Do you mean re-flash the firmware with the same version, in case it has become corrupted or with a newer version that fixes a known issue?

@Greenonline it makes no difference, either will fix the problem if it's a firmware problem. It's not an esoteric edge case problem, it's a core functionality issue.


text:
Post processing - How should I remove stringing for the smoothest surface?
On a PLA print where stringing has occurred, what is the best way to remove it during post processing?
Should I simply cut it with a hobby knife and sand the surface or are the better techniques to use?

If you already have a print you put a lot of time/materials into, then answers to the question as asked should be helpful. But if this is a general question for when it happens, you really should just get to the bottom of why stringing is happening, and fix it. Prints, especially in an easy material like PLA, should not have stringing.

Tring to fix the stringing too.

Use a hobby knife with a chisel blade (straight edge perpendicular to handle, beveled on one side only).
Apply with beveled edge against workpiece. Raise the handle in small increments while stroking over the flaw until it is entirely removed.  This provides pretty good control to prevent gouging.
Avoid sanding.
This method also works well for removing "ribs" caused by gaps in painter tape applied to print bed.

Why avoid sanding?

Sanding tends to dull any gloss on the surface in my experience.  It should be possible to completely remove strings without resorting to sanding.

Everything is going to be primed and painted, so the surface won't be visible.

Then don't avoid sanding if it appears it will be helpful.  Usually not necessary if just removing strings.

I pull them off by hand and then a few quick passes with a cigarette lighter works for me.


text:
Klipper: power on before homing
I'd like to force Klipper to perform power on (using M80) before homing. For this purpose I'm trying to override G28:
[gcode_macro G28]
rename_existing: G28_BASE
gcode:
  M80
  G28_BASE { rawparams }

But for some reason this does not work, I'm getting the following error:
G-Code macro rename of different types ('G28' vs 'G28_BASE')

Isn't G28 overridable? Is there any other way to achieve the desired behavior?

Because of the way parameters work differently (Sx vs NAME=x) for gcode style commands vs Klipper extended ones, the rename has to be to the "same type" of command. G28_BASE does not fit the pattern to be considered a "gcode style" one. Use G9028 or G28.1 or something instead and it should work.

Besides using a different macro, it is also possible to use [homing_override] which allows you to redefine the homing sequence.
You can write a simple homing_override like (untested!)
[homing_override]
axes: xyz
gcode:
  M80
  G28

and you are done.
Be aware that this very simple override will home all axes every time homing is called: "G28 X0" will home also Y and Z. You can put checks to home only what is requested, see here but it become more involved.

Thanks, I saw this. But I decided not to use this exactly because of the reason you mentioned: I'd like to be able to pass arguments as is to the default G28 implementation

If you check the link I provided, he homes only what's being requested by checking "{% if params.X is defined %}{% set home_x = True %}{% endif %}" and so on


text:
Why do most manufacturers recommend curing resin models before removing supports?
Why do manufacturers such as Elegoo always recommend that you cure your resin 3D prints before removing the supports, while hobbyist such as Uncle Joey usually recommend that you soak your models in warm water and remove the supports while they are soft, prior to curing?
Is there a firm and quantifiable reason for this difference, or does it purely come down to personal preference?

Just a guess, but manufacturers are probably looking at safety concerns vs hobbyists that are looking at practicality and workability.

If you care about dimensional accuracy, you probably want to cure them before putting stresses on them by pulling at supports.

It is likely that Resin manufacturers recommend this for two reasons:

Uncured resin is not safe to handle, and support removal requires handling and manipulating the part. Curing the part removes this safety implication, making support removal less likely to expose you to uncured resin via mechanical means and/or accidentally breaking your gloves with the tools for support removal.
Uncured parts are still malleable and prone to squishing or deforming under force. Curing parts will make them firm and insusceptible to deformation while attempting to remove support material.

However, Modern support patterns have become significantly easier to remove, Making it more of a personal preference rather than one with any merit behind it. Most recommend removing support material before curing as the 2nd point above can be taken advantage of to remove supports specifically, whilst keeping parts intact and accurate.


text:
Is there a method for telling how much filament is left on a spool?
Other than unrolling it and measuring it, is there a method for telling how much filament is left on a spool, for example calculating a length bases on weight or number of turns left on the spook?
Is it possible to extract the amount of filament used from the printer's firmware?

Are you looking for exact or approximate measurements?

If you have an empty spool of the same brand, you could weigh the empty spool and the one you're trying to "measure" to get an approximate weight of the remaining filament.  Divide by the (presumably available from manufacturer) weight per meter to get a rough length in meters, if that's more useful to you than weight.

Also weigh the spool before use, write the value on the flange (tare 304g) and measure, subtract. I've been using 1kg as the base and find that the manufacturer usually gives a few grams more, providing a safety net, a tiny safety net.

Most slicers will give you the weight of the part, so if you know the weight of the filament left on the spool, that might be enough.

@user10489 Hence "if that's more useful to you than weight."

Here is a helpful table of length per roll of different generic materials. It has 1.75mm and 2.85mm diameters: https://amp.rigid.ink/blogs/news/how-many-meters-of-filament-on-a-spool

If you use klipper you can use this script (by zellneralex) to calculate the filament length used since the last manual reset. Obviously it works with a single spool, if you switch spools it doesn't work.
If you want to know how much filament is left in the spool, the exact formula based on inner radius of the spool $r_{int}$ and outer radius of the spool when new $r_{ext}$ and based on the current outer radius of the remaining filament $x$ should be:
$$ 100 \left( \frac{x-r_{int}}{r_{ext}-r_{int}} \right)^2 $$
You can see that you get 100% when $x=r_{ext}$ (spool is new) and 0% when $x=r_{int}$.
It's a simple integration in $(x-x_0)\,dx$.

If you are down to one layer of filament, count the number of loops left on the spool, and multiply by the circumference of the spool to get the length. ($ \pi \times diameter \times loops $)
This can work if you have more than one layer and know the core diameter and the outer diameter of the filament left, but there would be some integration and a lot of estimation.

How do you account for the increase in diameter as the filament winds around the initial hub?

This might not work if a roll of filament isn't perfectly wound.

increasing diameter: that's what the integration is for;  not perfectly wound: that's why estimation is required.  I didn't say it was easy.  :)

I seriously doubt the wounding can appreciably impact the result.

See my answer for the correct formula

The winding will affect the result, but maybe not by a lot, that's why estimating works.

Some filament vendors put a window to see the remaining spooled filament with a decal showing graduations to match how much is left based on the diameter visible. You could do the same as a printed (in the paper sense) insert you slip along the inside of any spool between the filament and outer wall. You just need to compute the relationship between diameter and amount of filament based on the filament diameter and the number of turns per layer. Or you could just copy the design from a vendor who does this and figure it will be close enough.

I have seen a few on Thingiverse called "Filament Spool Gauge". It seems that they need to be made specifically for a brand/spool.

@agarza This is because vendors use different widths and core diameters of spools.  If they were standardized, it would work universally...

I made an Excel spreadsheet that calculates this based on the spool dimensions. You can download it here.
There are products available that will keep track of the length of spools once you give it a starting length. The starting length could come from the spreadsheet.

It's nice to offer various spools and lines for notes, but if you protect the workbook, it becomes a bit useless. It's not formulas are so difficult to calculate, so I think it's better to leave it open.

Ya... maybe I'll open it up.

Hmm... I don't think I'll open it up. It's made to work with the hardware I made that saves and tracks 10 spools. The spreadsheet can easily be saved with a different name and then you could keep track of as many as you like. The hardware just makes it convenient and user friendly. It can be found here on Etsy. (https://www.etsy.com/ca/shop/BrownsBrainShop)

Besides using the window on a spool that estimates the amount of filament left, I've used large calipers to measure the diameter of an empty spool and the diameter of the filament left on the spool.

Why not use a database online with a filament consumption counter?
See this link.
You can create a database without buying counters. I have two printers an Ender and Mega Zero and 2 counters that automatically consume the selected filaments.
Very cool tool. I love it

This is comparatively pricey compared to a filament gauge that I can print rather inexpensively.

I agree with you. This is for professional users only but remains the best way to track filament consumption. In any case, here you can see the link and use the manual database without buying counters


text:
Artifacts on layer in one direction
I have an Ender 3.
When my printer is laying down a flat layer and is going from left to right, it lays down a nearly perfect layer. However, when that same layer is going right to left, I get artifacts.
These artifacts make a design which must tell me something but I can't think of what it could be. What would cause artifacts to appear only in one direction?
Here you can see it is currently going from right to left at a diagonal. The layer below this one was flawless!

Welcome to 3DPrinting.SE! This is a possible duplicate question, does this answer your question?

i don't think that answers the question. The question and answer for that was due to the hot end temp and cooling fan. The issue i am having is related to the direction the printer is going, i don't think that is related. If it was a hot end or cooling fan issue, it should be present at all time regardless of direct, right?


text:
Blown two Ender 3 stepper drivers
I have an Ender 3 3D printer, and I upgraded the extruder driver to a metal drive one. Since the gear that drives the filament was pressed onto the factory stepper motor I replaced the motor with a similar-sized NEMA 17 stepper I had laying around. I successfully completed some prints when I noticed the Z-axis was skipping steps and had lost most of its torque. I swapped the Y- and Z-axis motors around and sure enough the problem moved to the Y-axis. Figured I had blown something in the motor driver but wasn't sure what.
I ordered a 4.2.7 mainboard, swapped the boards over, and turned it on. Tried homing the machine and all axes worked other than the Y-axis. This time it's not skipping steps just not working at all.
I'm very confused and 2 mainboards deep and still unsure what the issue is. I did test the resistance across the phases of my new extruder motor and it measured about 2 ohms whereas the other motors were a bit higher. So I'm thinking maybe it's that motor but the extruder driver has been working fine.
I've also noticed on both boards one of the diodes next to the blown driver has some white stuff on it. Not sure if they're blown or that's normal.
Any help will be greatly appreciated.

I'm not sure about this (wait for answers from someone who understands it), but if the stepper drivers are old non-TMC ones with a pot-adusted vref, it sounds vaguely plausible that you'd have to adjust that to avoid exceeding the current limits when the resistance is lower.

If the problem axis followed the motor swap, that eliminates the driver as a cause. Can you post a pic of the "white stuff"?

So the (now) Y stepper is not moving while it barely moved after the Z to Y conversion where the (now) Y stepper was the Z stepper which already had issues in Z movement in the first place? Isn't this just a stepper that is not working (strange because to my knowledge steppers are pretty robust). I'd by a new stepper to be sure to troubleshoot the issue. P.S. I hope you did not pull the stepper wires while the board and steppers where powered, it is known that that may harm the stepper drivers.

Sorry for the confusion, with the old board the z barely moved. I then, (with the board powered off),  switched the x and y motor leads. After that the y axis barely moved. So the issue went with the driver not the motor.
Now with the new board, the y axis doesnt work and swapping the motor leads with any other axis causes that axis to not work. So ive somehow blown two drivers but not sure what. Not entirely sure how to link a photo of the diodes sorry

@benjaminhk12 you can [edit] your question and upload the photo with the button with 2 triangles and a circle on it.


text:
Getting a "no printer attached" error after hotend swap out
I have an Artillery Sidewinder X1 that had a stripped-out screw. I couldn't find a single screw anywhere and opted to replace the entire hot end, screws, fans, and everything. Should have been pretty easy, and was - 3 screws and a ribbon cable. Now when I turn on the printer I get the "no printer attached error" on the TFT display.
I've searched Google and can find no help there.
Any ideas would be gratefully accepted!
Firmware: RAWR 28.x
Board: TFT version Artillery (stock)

Hi welcome to 3DPrinting.SE! Please describe which application throws the no printer attached message, or is this the printer display? Long shot, but are you sure the flat cable is connected and properly inserted?

Sorry if I'm not very clear, but of course I'm new here.  This is a stock 18 month old Artillery Sidewinder X1, with the exception of the RAWR firmware which has been working perfectly.  I had problems with the hotend hardware and just replaced the whole thing.  As I mentioned above, it was just 3 screws and the ribbon cable.  Should have been easy.  Now when I turn on the printer I get the "no printer attached error" on the TFT display.  I appreciate your comment and it has me wondering if there is a problem with the ribbon cable.  Shouldn't be but I'll check.  I open to any ideas you have!

Just to eliminate errors, maybe you could use the ribbon cable from the old hotend to check. Also, and this would be a right pain admittedly, as a sanity check maybe just temporarily wire back in the old hotend to see if the old hotend assembly (now) gives the same error (as previously it presumably didn't). After that, it could be a process of elimination, swapping each part in turn, checking to see which new part is causing the issue. Also, possible disassembly and reassembly might magically fix any dodgy connection or wiring that occurred during the initial swap out. Just some thoughts...


text:
Deep ridges in all of my prints
I'm using an Elegoo Mars 3 printer.
For some reason, all of my prints are now getting these deep ridges. each layer I can hear it peel away from the vat before it lowers again for the next layer.
I've tried various exposure times as well as different approaches to supports.

that'S really hard to see, but I guess you mean the ripple pattern in the horizontal? how old is the resin un the vat? As in: has it been opened a long time? I have a gut feeling that possibly there is something wrong with the model bending in some way when returning to position, and that might be either a printer or a resin having degraded.

Open Resins degrade
If photopolymer resin is sitting open a long time, its curing behavior can degrade. One of the effects of degrading resin is, that it might not harden to the same point in the same time, requiring either longer exposure or not curing to hardness at all.
This can lead to the prints staying somewhat flexible when they get peeled off the sheet, and when they get pushed back into the print position, that can lead to the print having a misalignment in one direction. As the next layer is added, peeled and repositioned, this might very well result in the "banding" pattern in layers all orthogonal to Z.
That this is a systemical error that happens everywhere in the vat you can notice at the support structure: it shows the same banding.
Solutions?
You might want to toss that resin, or at least add some virgin resin to it, so it can get refreshened.
As a general rule of thumb, it is not advisable to leave resin and vats out in the light for any prolonged time and if you don't print for several days, it is best practice to drain the Vats and store the resin in light-tight bottles.


text:
Little help on this Cura slicing or model error?

The left part of the first picture is giving an inverted circle when lying flat, but the right part of the first picture is how it should be. Same STL for both slice orientations. I tried toggling union overlapping volumes with no luck. I tried to invert face normals with Blender with no luck either.
This gives the error: The highlighted areas indicate either missing or extraneous surfaces. Fix your model and open it again into Cura.
Here is a link to the model, this is another link.
I have tried

manually repairing faces with Blender,
repairing the model with Autocad Meshmixer

both without success.

Cura is explicit on your model, it is broken. A valuable tool was the online Netfabb STL repair service, this now appears to be integrated in Fusion 360.

That's a model error - the bores have inverted faces.

Windows 10 3DBuilder wipes out the counterbores and turns the surface into a flat area, as does Meshmixer. The creator (you?) created a non-manifold object that resists repair.

I've discovered via Meshmixer that there are duplicate cylinders for the counterbores. I selected "separate shells" which generated two sets of cylinders in the Objects Browser as well as the main body. Selecting each flawed entry in the browser left behind the main body, which is manifold and passes the Analysis/Inspector test sequence.
You can have the repaired file from my Dropbox, public folder, or you can perform the process on your own. If you select the former, please let me know when it's retrieved, as I endeavor to keep my space in the free category on Dropbox.


text:
Stepper motors on the extruder and Z-axis seem to freeze up during any fast movements
OK here's some background of the problem:
Symptoms:

All retracts on the extruder produce a screeching noise. The extruder extrudes normally all other times.

Any fast move on the Z-axis also produces a screeching noise and the Z-axis will move normally at all other times.

This appears to happen regardless of any printing state whether the heaters are on or not it will still occur it even happens during the ABL process.

Specifications of the printer:

Mainboard: MKS Gen L V2
Drivers: TMC2209 UART
Stepper motors: Stepperonline 17HS15-1504S 1.8 deg 1.5A
Pulleys: GT2 16T
Leadscrew: 2 mm pitch T8
Hotend: E3D V6

OK so basically I performed an upgrade of my stepper drivers as well as the leadscrew and pulleys on my 3D printer which was originally a Tevo tornado and at the start of every print I would experience a loud screeching noise coming from the Z-axis and I originally identified it to be a single line in my G-code that would only trigger the screech if it was preceded by another line and by commenting out the first line I was able to start printing
Lines in question:
G1 X3 Y1 Z15 F9000 ; Move safe Z height to shear strings
G0 X1 Y1 Z0.2 F9000 ; Move in 1mm from edge and up [z] 0.2mm

However, while I was able to start printing, I soon found out that the extruder was doing the same thing with every retract it would create a loud screech and the filament wouldn't be retracted this caused heavy stringing as well as poor layer adhesion resulting in prints failing. I figured the problem was with the version of Marlin I was using so I attempted to use the latest bug fix. However, I was still experiencing the same problems. I attempted to see if the stepper current was the problem and after identifying that the stepper current was not the cause of the problem, I figured I needed to replace the stepper motors and after replacing the stepper motors the problem still remained. I figured the problem must be with Marlin so I attempted to use Klipper. However, I am still experiencing the same and now I can't even complete a mesh bed leveling as the movements that Klipper uses are triggering the loud screeching and causing the steppers to freeze up.
I am unsure as to what could be causing this as I think I've checked everything that could be causing it so I'm not quite sure how to proceed I've also made a video that should show the problem in action. So I guess I'm wondering what's my next troubleshooting step?

I have tried changing the drivers back to TMC2208s there have been no changes on both Klipper and Marlin.
I tried switching to an MKS Gen L V2.1 in case it was a mainboard problem, still experiencing problems.
The only other thing I think I can try is running the TMC2209s in standalone mode

I can't find anything suspicious in the Klipper config. Aside: this isn't your issue, but the non-whole-number rotation distances for X, Y, and Z are almost surely wrong because of how timing belts and lead screws work. If you measured X and Y errors that you were trying to correct for, they're almost certainly extrusion width errors (which don't scale with object size, unlike esteps errors that would scale with object size) or backlash that needs to be fixed mechanically. Likewise Z is almost surely a bed height error.

just tried fixing that still no change.

Yes, I wasn't proposing that as a solution to your problem here, just a note about something else that will come back to bite you if you care about dimensional accuracy.

I've watched the  video now, BTW, and I don't immediately have any other ideas for solving this. I'll follow up later if I think of anything else.

I haven't had time to view the video, but in general, the symptom you're seeing means you're trying to drive the stepper above the max RPM it can handle. Roughly speakling, coils (in the motor) resist a change in current, and past a certain point, a given voltage is insufficient to change the coil currents to perform a step before it's time for the next step. Typical steppers in cheap 3D printers max out around 1500-2000 RPM and lose power (meaning they'll likely work under no load) a little bit before that.
To figure out your motor RPM, multiply the axis speed (in mm/s) by steps per mm (full steps, not microsteps, so divide by number of microsteps per step) to get steps/s, then convert to rotations/min by multiplying by 60 and dividing by 200 (steps per rotation for a 1.8° stepper).

Ok so my printer worked with the same settings before at least for the extruder (can't say this about z cause of the lead screw upgrade) and my extruder steps per mm are 400 and the retract speed is 30mm/s so that would put the RPM at 3600 so I guess if that is something the TMC2209s can't handle then I might go back to the TMC2208s

@DexterGrif: Keep in mind steps/mm here means full steps not microsteps. I'll clarify that in an edit later. So it might not be as high as you calculated. 30 mm/s retract should be no problem with an ungeared extruder; only with a very high reduction ratio would that be problematic.

it is using a titan extruder so I am unsure how that changes things. also I am using 16 microsteps

@DexterGrif: That should just be 25 full steps per mm and thereby 225 RPM.

ok so the output of M203 (Max Feedrates mm/s) is:
M203 X250.00 Y250.00 Z30.00 E55.00
so the RPMs are
RPM=(((x*x_steps)*60)/200)/16
X=476.85
Y=472.5
Z=907.3
E=437.8
so that looks like it is within the limits.

@DexterGrif: Are you sure you don't have any start gcode or anything overriding those limits on a per-print basis?

Let us continue this discussion in chat.

The maximum RPM depends on motor current. Higher current, lower max rpm.
I checked your klipper.conf and I can say that you should definitely reduce the currents for all motors. Extruder and Z motors at 0.9 A is crazy, for example. X and Y 0.7 A is enough, for Z and extruder 0.4 A is good already.
Also, you request F9000 which is impossible on that printer, therefore you are automatically limited by the firmware max speed. Try manually asking a more reasonable speed, like F2000. Keep decreasing until it works. Try decreasing the acceleration too: you have 120, try with 50 which is good already for Z moves. If it works, increase it progressively.


text:
CR Touch firmware NO Z-axis home Ender 5 Pro 4.2.7
I purchased a new 4.2.7 (256k) board for my Ender 5 Pro and added the CR Touch. I got everything connected and flashed the board with the "Ender-5 Pro- Marlin2.0.1 - V1.1.1 - ALT - TMC2235.bin" firmware from the creality.com/download > Accessory Firmware > CR Touch Firmware for 32-bit Motherboard > Ender-5 Pro.zip
Problem:
When told to Auto Home the Z-axis drops 5 mm then checks X-axis & Y-axis endstops = OK
But then the Z-axis drops another 3 mm and the CR Touch deploys > Retracts > deploys > Retracts and Faults out.
The instructions say to move the Z-axis to get the offset but it will only go down while the CR Touch is faulted (Stopped)
I've checked all wiring made sure the Z-axis endstop was disconnected. No help.
Thinking it was a board issue I wanted to check the normal, no CR Touch, functionality, so I flashed the Marlin2.0.1 V1.0.1 original versionTMC2225 "Marlin2.0.1 - V1.0.1 - Endstop - TMC2225.bin" firmware onto the board, and reconnected the Z-axis endstop. The printer worked like normal.
Not wanting to fail, I decided to try another firmware, so I decided to use TH3D_Unified2_CrealityV4X_256K. I went through and set up everything using CUSTOM_PROBE settings. And wouldn't you know it... SAME Results as with the Creality "Ender-5 Pro- Marlin2.0.1 - V1.1.1 - ALT - TMC2235.bin" firmware.
Bed drops 5 mm at the start of Auto Home then drops another 3 mm after centering to deploy the CR Touch. The CR Touch deploys > Retracts > deploys > Retracts then Faults out. At no point does the bed ever try to go up.
The only other thing I can think of is that the CR Touch isn't working right. I thought it was supposed to deploy then the bed was to come up to it to detect it. Could the wiring "harness" for the CR Touch be incorrectly wired? (Wiring below)
Can someone help me with this one?
Do I have a bad Board?
Do I have a bad CR Touch?
Or am I just not getting a setting right somewhere?

CR Touch Wiring (Current) 5pin from factory --- Connectors can only be put in one way
@ Creality 4.2.7 Board --- From Left to Right
G = White | V = Black | IN = Yellow | G = Red | Out = Blue
@ Creality CR Touch --- From Left to Right with Creality logo facing you
Blue | Red | Yellow | Black | White

Did you ever get a suitable firmware working with this configuration?
I have an ender 5 pro - upgraded the mainboard to a 4.2.7, added a genuine Creality CR leveller and filament runout sensor. I cant get a Firmware from anywhere that seems to work with this set up.

No help here but to confirm that on my Ender 3 Max (4.2.2 board) with a new CR Touch, the sensor lights up and responds to Deploy/Stow test commands.  When I execute Auto Home, it does descend to find the bed position but does so with the probe retracted, and if I let it continue would crash into the bed.

A friend of mine has this exact same setup and this exact same problem. Have you guys found any solution yet by any chance?

What you describe is very common behavior for a faulty sensor or bad wiring. I've had my fair share of knock-off BLTouch clones that show this exact behavior. When replaced by a genuine BLTouch sensor, the issues where gone. You might have gotten a defective sensor. You should write the vendor that it doesn't work and ask for a replacement.

Make sure that you’ve changed the G-code in your slicer so that it uses the auto leveling. I forgot to do that when I installed a CR Touch on my Ender 3 and the behavior was similar to what you describe: the printer would deploy the CR Touch a couple times, and then just stop.
Adding a G29 instruction to the G-code in Cura’s printer configuration (I put it after the G28 instruction) will tell the printer to use the auto bed leveling. Once I did that, the printer started working as expected.

Comment this line:
Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN (comment=// before the line). So you search for this line in the config file, comment it in order to disable it.
2nd step, uncomment:
Z_MIN_PROBE_ENDSTOP so delete the // in front of the line.

As it’s currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.


text:
Bottom part of spherical objects print problematic
I got a Flyingbear Ghost 4 and using Cura. It is doing fine until I have to print spheric things. I'm using a high density material that needs to be at 210 °C and slower print speed. I also built a top and a door for my printer so it's partly enclosed at 90 %
An easy example of what I got is a sphere object.
The lower half is messy with uneven surface, lot of visible strings marks at firsts layers. While upper part is just perfect. I tried to to work around it multiple times but can't find any worthy info on internet. Tried to slowing down the printing speed by max 50 %, thicker shell, nothing seems to work.
Here a Lapras I did to my son to show you.

Settings:

Fan_Speed : 100 % (it's off for the first layer)
LayerHeight : 0.1 mm
Bed_Temperature : 60 °C
Nozzle_Temperature : 210 °C
Nozzle_size : 0.4 mm
Shell_Thickness : 1.6 mm (so 4 passes)
Printing_speed : 45 mm/sec (max moving speed for this printer is 150 mm/sec,
default printing speed is 60 mm/sec)
Support_type : Everywhere
Support_Min_Angle : 59°

Can you help me with this?

Please add a photo to show the problem otherwise the question may end up being closed for insufficient amount of information to solve the problem.

This is a potential duplicate question of this question.


text:
Print Head Cable, does such a thing exist?
As the printer ages, the constant motion of the print head wears out the conductors inside the cable. Creating all sorts of fun debugging scenarios.
Is there such a thing as a bundled cable, with all the necessary wires, for the stepper motor (in the case of direct drives), hot end, thermistor, etc... and when one of the conductors wear out just replace the whole bundle?

I’ve seen a printer use an HDMI since the cables and connectors are dirt cheap from China. You can repurpose just about anything that’s widely available (DP, Ethernet, etc) as long as you use 24V on enough pins in parallel for more power.

People have used parallel port cables (DB25) for a while. They are cheap enough and have enough pins for most uses.

Obviously you will need to use multiple pins for the power hungry devices (heater, stepper motor). Parallel cables often use 28 AWG (0.08 mm^2) wires, which carry up to 1.5 A @ 30 °C temperature rise over ambient. It's quite a lot, so better stick to about 0.8 A/wire, which means one pin or better two are enough for each wire of the stepper motor. A 12 V/50 W heater draws 4.2 A and will likely need 5 pins per each wire, to be safe while a 24 V/50 W heater could work with two.
See some ratings here.
You can also use Ethernet cables, they are even cheaper and more widely available, but each cable has only 8 of them. The advantage is that they are usually 23-24 AWG (0.21-0.26 mm^2), unless you look for slim or flat cables, 30-32 AWG, so the heater will need fewer wires. However, they are all twisted pairs therefore you may be forced to use more wires than you need: for example, you may have an accelerometer which uses four data wires: TX, RX, clock, enable. You cannot twist RX and TX to avoid interference, and also clock should not be twisted with either RX or TX. You may need to be creative (TX/GND, RX/VCC, clocl/enable), but in general it's uncommon.

What heater is that? a 12 or a 24 V one?

12 V, 50 W is 4.2 A, which is about 5 wires at 0.8 A/wire. Of course at 24 V 2 wires are enough. I gave the initial general rule, adapting to each case is task for the reader :)

Those things are quite heavy to put on a toolhead...

@R..GitHubSTOPHELPINGICE a PCB RJ45 socket or two and the RJ45 plugs on the cable are not. The DB25 is heavier (50 gram) but likely acceptable for many printers. I mean switching from a direct drive with NEMA17 to a Sherpa mini or Orbiter saves you more than that...

@FarO: Well yeah, but I consider those NEMA17 direct drives a relic of the past and the toolhead weight with a Sherpa Mini or Orbiter the baseline you should be figuring weight costs from. In which case 50g is a significant % of the total toolhead weight for something that could be less than 1/10 of that.

The many manufacturers create the printer configuration in nearly as many ways as there are models of printers. I've seen flat flexible cables used in a manner akin to cable chains, which allows the ribbon to roll back on itself in the return movement. Minimal flexing at the end connectors and an acceptable radius on the bend. My BCN3D Sigma R16 has a ribbon cable from a fixed location out to the head, which travels in both x and y direction preventing a roll-back/cable chain type of configuration but also maximizes the radius of the bend.
If you are considering a DIY printer build, your options are open, but if you have an existing unnamed printer, your modification has to remain within the constraints of the manufacturer.

Have you thought of using a ribbon cable?  I have/ have had similar issues with a large print area CoreXY.  I'm not sure if the ribbon cable can handle the motor current or heater current but pairing up wires may help. One other issue you may have is electrical interference if you have bed leveling that uses a servo command.
I'm going to try a ribbon cable on my next print head rewire.

You may be able to find replacement wiring harnesses from a good manufacturer that supplies replacement parts for its printers, or possibly a 3rd party replacement for very popular printers, but there is no standard for length, number and types of conductors, gauge of wire, and types of connectors for the ends.
For connectors, many 3D printers have settled on “JST” headers on the ends. There are several types and pitches that aren’t compatible so identification is important when finding a replacement. Here is a good resource on identifying the connector: http://www.mattmillman.com/info/crimpconnectors/common-jst-connector-types/
An alternative to finding the correct pre assembled wiring harness (not out of the question with the explosion of 3D printers and CNC machines) is salvaging the original plastic header and crimping new connectors on new wires. This sadly requires a special crimping tool, but it is a worthwhile purchase if you do electronics.
If the 3D printer uses a ribbon cable, it isn’t terribly hard to replace those, if they use the rectangular IDC connectors at the ends. You can cut the cable to length and punch down the connector in a vise.
Whatever the connector or type of cable, for the wire, the finer the strands of copper the better, as far as resisting breakage from constant movement. One good source of salvaged fine stranded wire is the cabling in wall warts (so long as 2 conductor works for you, say for a heat bed).
As others have noted, the bend radius of the wire has a lot to do with its longevity. Sharp kinks will do the harness in, especially at the printhead end. Strain relief is key, as is not nicking the wire where it is stripped. Most cables, in general electronics, seem to break at the ends.
In shopping for a printer, it’d be good to check the cabling doesn’t pull directly on the connectors when it moves, doesn’t kink it, especially if it has DIY mods done to the print head. For printers you already own, check the strain relief. Other than that, wait for it to break, rather than ripping it out just because you’re worried it may break. It isn’t hard to diagnose with the continuity tester on a multi-meter. In a repair you can always leave the old broken wires in there and add a couple new ones. Pay attention to wire gauge, as others have pointed out- fans, thermistors, other sensors can be small, hotends and steppers larger, heatbed largest.


text:
Can I combine several ".CTB" files together into a single file?
I've used Chitubox to add supports to a number of models and saved them as .CTB files ready for printing.
If I want to print several of these models at the same time, is it possible to combine them into a single file and to assign each one a different location on the built plate?

The files generated by a resin printer slicer contain exposure reference information as well as an image for each layer to be printed. One could consider to develop a reverse-engineering bit of code to read all of the image layers, overlaying the common z-height with the others to be printed and hope that none of them create overlaps that would destroy the models being printed.
One can, for example, configure PrusaSlicer to create a print file, change the name to *.ZIP and extract the multiple *.PNG files within. Consider how difficult it would be to composite these individual PNG files when combining them with another file or multiple files.
The web site 3dprintknowledge contains a beginner's reference with a useful image:


text:
Prusa i3MK3S+ layer skip with polycarbonate (overheating?)
On the last couple of polycarbonate prints with my Prusa, one or more layers have been completely skipped (i.e. no material extruded). The rest of the print is fine save some minor warping. I'm printing in an enclosure that gets up to ~60 °C with the power supply outside the enclosure. I'm also printing out of a dry box with a fairly long bowden tube. I suspect it has something to do with overheating because this doesn't happen when I print without an enclosure.
I cracked the print in half just to take a look in between the layers.

If you print the same thing twice, does it skip the same layer or random layers?

60 deg C in an enclosure seems really hot, can the rest of the parts in there handle that?

Turns out I was just ruining the PETG parts that held the extruder gears. They didn't really melt but got soft and crept really badly. I replaced them with new parts everything was fine.

If you are experiencing overheating, consider to provide input/output airflow to the enclosure for the controller board and for the power supply. I've seen elsewhere on the 'net (forgotten locations) of Prusa printers with DIY extensions to the cables that are used in those components, allowing them to be located outside, with ambient airflow.

The power supply is outside the enclosure but not the board.

I think you have at least a partial answer in your comment.


text:
Can I connect a PSU with a higher current rating than RAMPS 1.4 can handle?
I have a 12 V/30 A power supply. Will a RAMPS 1.4 shield burn if I use that power supply with it?

This question appears to be a duplicate of a question you asked back in february, which already has an answer.

The title is considered to hint to a duplicate, but the body of the question asks if a certain PSU can be connected. The answer of both questions are closely related. I think the OP doesn't understand that you could even wire up a 12 V/1000 A PSU, it is not the PSU that determines how much current is being drawn, it is the peripherals that determine this. I have proposed a new title the OP may reject.

Does this answer your question? What is the maximum input ratings for current, voltage and power for RAMPS 1.4, 1.5 and 1.6?

@0scar I want that 1000 Ampere 12 V power source - that's 12 kW!

@Trish Not as crazy as it sounds since you can use the current sharing pin on server PSUs to merge several of them into one large redundant PSU. I use three 12.2V 55A PSUs in parallel to run my desktop and in a few months I’m planning to upgrade to ~500A split across 2 PSUs and 2 breakers.

Voltage and current behave differently and it is important to remember two essential points:

PSU voltage specifications should never be exceeded, else the circuit will (most likely) be damaged, and;
PSU current specifications can be exceeded, without any risk to the circuit1.

So, if your circuit requires 12 V and 3 A, then the PSU must supply a maximum of 12 V, but current can be 5 A, 10 A or whatever.
It may help to think of it this way:

Voltage will force its way into a circuit, and if you exceed the specified requirement of that circuit, then the circuit will be damaged, for sure;
Current passively sits there and is is only taken by the circuit as it is required - if your power supply can provide 1000 A, but the circuit only needs 11 A, then the circuit will only take 11 A. The remaining 989 A will be ignored.

Note: There is one caveat, where the mismatching is reversed: If a PSU can only supply 5A, but the circuit requires 10 A, then the PSU may be damaged as the circuit attempts to draw more current than the PSU can provide.

The water analogy
You can think of electricity as similar to water in a water tank, and a tap as being the outlet/socket/circuit:

The higher the water tank is above the tap, the higher the water pressure - this water pressure is analogous to voltage. If the water pressure is excessively high, then the tap could fail, in the same way that a circuit will blow,
The larger the tank, the more water there is that can be provided - This capacity of the tank is analogous to the current. You don't have to use, or drink, all of the water in the tank, but (often) it's nice to have an excess available, even though it might be wasteful or not particularly cost effective.

Footnote
1 The only major downside to having an over rated PSU with respect to current, is that should the circuit that the PSU is supplying have a issue, such as a short circuit, then a lot more current will be drawn, than if the PSU wasn't so over rated. This could be dangerous, if, for example, you are touching part of that circuit. This is why the current rating of a PSU should closely match the current requirement of the circuit which the PSU is supplying.
Other considerations for using an over rated PSU could (arguably) include a longer life or increased reliability. This would be due to less stress being placed upon the PSU, if the current rating of the PSU is, for example 25 - 50 % greater than the current requirement of the circuit.

Yes you can connect that PSU to the RAMPS 1.4 shield, and no, it will not burn the shield under normal operation (too much and/or too high current draining peripherals attached or shorting of circuits).
It is not the PSU that determines how much current is being drawn from the PSU, it is the peripherals that determine this. The RAMPS 1.4 shield has (poly) fuses for 11 A and 5 A, so the maximum you can draw through the board is 16 A. You cannot draw more than 11 A for the heated bed, and 5 A for the hot end heater and the steppers combined. If your heated bed uses over 11 A or the rest over 5 A, the fuses will burn through cutting the circuit. These fuses are meant to protect your board from draining too much current.
Connecting a PSU with a higher current specification is perfectly fine as long as you do not exceed the board specifications with your peripherals.
In case your heated bed (which takes the majority of the power) requires over 11 A (which requires thick cables!), you need to use an external MOSFET; this doesn't add a safety, it merely allows to use more current from your PSU to power the high demanding peripherals.

No, it won't burn if you use a power supply that put out 12 Volts and tolerates up to 30 Amps.


text:
Why is my PSU turning on and off automatically?
I have 12 V/30 A PSU. I have also installed the firmware onto the Arduino Mega2560. But the problem is that the display on the LCD keeps turning on and off automatically (it's stuck on the Marlin logo because it keeps restarting).
When I hear the PSU fan, it also turns on and off automatically. I suspect that there is something wrong with my PSU because when I supply power directly using the Arduino Mega's port, the display didn't repeatedly restart automatically.
When I connect an LED to the PSU, it blinks. It blinks and continue goes normal. It keeps repeating like that.

Connect a voltmeter, scope, or an led+resistor to the PSU output and see if it blinks or stays on continuously.

It could be broken, buying a spare doesn't cost much and you'll be able to troubleshoot. But, since you have supplied another power source which doesn't show the intermittent on/off behavior, it is most likely the PSU is faulty.

Does the PSU behave in the same manner when not under load (without the printer or anything at all, connected)? Without photos of the inside of the PSU, or any results of testing various components within the PSU, it's going to be rather difficult to provide a definitive answer.

Hi, I already change to the new PSU. I also already test the PSU using LED. The LED constantly turned on and no blinks. But the issue is, when I plugged in the RAMPS 1.4, the PSU start giving the LED blinking again.

Previously you had said that when an LED was connected to the PSU, then the LED blinked - giving the impression that only the LED was connected to the PSU. Now you are saying that with only an LED connected, the LED does not blink..! If previously you had connected the LED to the PSU, whilst the PSU was still connected to the RAMPS and exhibiting the stop/start behaviour, then obviously the LED would blink as well. So, to clarify: When not under load, the PSU is fine (both the old and the new PSU), but when under load the PSU stops and starts... is that correct?

To me, if seems like you are attempting to draw too much current from the PSU, and it shuts down momentarily, as part of its self-protection. That seems to be the most logical, and obvious, reason. Try disconnecting one of the high current draw devices, i.e. the headbed, and then see if the PSU works OK. If so, then the heatbed needs a separate supply as per my previous answer.

Simple answer
If the PSU continuously restarts, even when not under load, i.e. nothing is connected to it, then it is clearly faulty.
If you then connect this faulty PSU to a 3D printer then the printer will not work either.
The long and short of it is: The PSU is faulty; buy a replacement.
Given your previous questions, and apparent high current requirement (heatbed, etc), you may have damaged the PSU by attempting to draw too much current. If so, then any similar spec'd replacement PSU will probably suffer a similar fate as this one.

Guesswork answer
As to why it is restarting could be down to a number of factors. The most common failings of LED PSUs (assuming that is indeed what it is) is one (or both) are the power FETs (usually there are two of them), which are bolted to the side/rear of the case. This fix is to simply replace them, like for like.
The FETs are by no means the only possible issue - there could be a faulty/blown capacitor, or any other of the components. The only way to tell for sure would be to open the case of the PSU and visually inspect the PCB for burn marks, and maybe thereafter probing it with a DMM.
However, if you don't know what you are doing, then don't attempt this as as mistakes could well be dangerous and/or fatal.
IMHO, cheap unbranded LED PSUs have a notoriously bad reliability. You will probably find that you have better luck using a branded ATX PSU for a PC instead.


text:
Does 3D printed Alumide out gas after printing?
Does 3D printed Alumide outgas or is it inert? I.e. If I printed a box with it and stored paper in that box for 100 years would the paper become damaged by out gassing?
I noticed that NASA has a list of materials that out gas.
But I'm not sure exactly what polymers are in 3D printed Alumide...

Alumide is, as this question explains made up entirely of Aluminium Grit and Polyamide 12 dust.
The Database contains one entry for Polyamide 12 (by filtering for it here):

Some other items of similar material (Nylon 6 & Nylon 12) are also in the database:

As a result of the material being essentially aluminium and PA12, I would take the PA12 values for an estimation until the material was tested properly.


text:
Can I plug in Arduino Mega USB input (to supply power) and RAMPS 1.4 power input at the same time?
Can I plug Arduino Mega USB input (to supply power) and RAMPS 1.4 power input at the same time?
This is because when I plug the PSU into the RAMPS 1.4 alone, the LCD keeps restarting and it just gets stuck at the Marlin logo but if I plug the USB to the Arduino Mega alone, it works perfectly fine except the motor won't move (maybe not enough power) or maybe there is any other suggestions?

Considering the amount of questions and problems with the RAMPS shields, I'd advise you to buy a proper control board and a decent power supply. The
RAMPS shields are pretty outdated nowadays.

Can you suggest the proper control board?

Any 32-bit board, look at the BTT SKR boards.

"any other suggestions?" - Disconnect the heated bed (in order to reduce the current draw) and hopefully that will solve the immediate issue. Then use your second PSU to power the heated bed separately, using an external MOSFET, as per this previous answer. You shouldn't need to provide a separate USB power supply once you have done that.

But I didnt install any heated bed.

Ah ok, but in your first question you stated "I total my heatbed + hotend + other components", so I assumed that you had. So, what exactly is connected to the PSU? Just the RAMPS and the motors? Anything else? Hotend? Maybe it is just me, but this is getting rather confusing, and it is unclear what is causing the current draw (if indeed that is the actual problem that's causing the PSU restarts). Also, do both PSUs behave in the same manner, both of them are stopping and starting?

I install hotend, 4 nema stepper motor, cooling fan for hotend,lcd, RAMPS 1.4 and Arduino mega 2560 with the PSU. Both of the PSU will not on and off automatically if i only check the PSU with LED. But it will starting to on and off automatically if I plugged in the RAMPS 1.4

Yes you can, that is the purpose of diode D1 on the RAMPS board.
It should be noted that if the RAMPS 1.4 does not have diode D1 then the Mega2560 will/can not be powered via the RAMPS board and it is necessary to power the Mega2560 separately, for example via the USB.
See 2.7.1.1    Power for the Arduino Mega board on the RAMPS 1.4 RepRapWiki page:

Power for the Arduino Mega board
The RAMPS 1.4 has a 1N4004 diode labeled D1 which allows 12V to feed
and power the Arduino Mega 2560 board. This diode is installed in most
pre-assemble boards, thus the Arduino board is powered by the Ramps by
default.
When the RAMPS is not powered or if the diode is not installed or
cut/removed, the Arduino gets its power from USB or a power supply
connected to its 2.1mm (center positive) power jack.
The Arduino provides a Vin connection to connect an external power
source that can be from 7V to 12V, remember the diode D1 can not be
connected if you plan to power the Arduino using its Vin.

The Arduino Mega is not rated for voltages higher than 12V. If your board has a 1N4004 diode soldered in Diode D1 (which is the case with
most assembled board), do not apply more than 12V in the 5A connector
of your Ramps, refer to RAMPS 24v for more information.


text:
What polymers are used in 3D printed Alumide?
Does anyone know what polymers are used in 3D printed Alumide? I know it has Al and nylon, but does it have anything else?
NASA has a database of materials that out gas and I'd like to see if Alumide out gasses.

Alumide is a registered trademark. It's source words are Alumunium and Polyamide. The first materials known under this name were sold in 2007.
According to my materials provider, the ratio is but for tiny tollerances exactly 50% Polyamide-12 dust that is enriched with 50% aluminium particles and the material is used without special alterations to the machine in a typical nylon Selective Laser Sintering machine using a modified profile for PA12. Its MSDS only lists those two components, so there is nothing but those in it usually.
As a result, the polymer binder is only Polyamide 12


text:
Why should the bed be leveled and isn't just fixed optimally?
In every 3D print that I have seen, the bed should be leveled (manually or with some sensor-based system) on multiple points, pretty annoying because often when you reach the perfect distance on a point another point should be adjusted again repeating the procedure multiple time to have perfect leveling on all points.
I'm wondering why height isn't just fixed with the optimal leveling.

There are printers leveled in the factory: https://www.silhouetteamerica.com/featured-product/alta-plus they level the bed (well, the print head in fact) for you once and you likely won't need to do it again.

The point of "leveling" (tramming) the bed is to make it:

square with the coordinate system of the printer so that it lies in a plane perpendicular to the direction of Z travel, and
a known distance from the nozzle tip at one point (and thus, due to (1), all points) in the plane at any given Z value.

In theory, if the machine were all preassembled and sufficiently/perfectly rigid, this could be done once at the factory and never need leveling again. However, even if that were possible, there's at least one factor that will throw you off: you're going to want to swap/replace nozzles, and they will not all be exactly the same length - especially if you use different nozzle diameters, styles, materials, from different manufacturers, etc. This is why, even with an ABL system, unless it performs probing using the nozzle tip itself, you always have to calibrate out the offset between the probe and the nozzle tip.
In practice, many machines (especially affordable ones) require final assembly by the consumer, which necessitates calibration. They also have parts which can warp or wear and require adjustment - especially POM V-roller wheels - which will then throw off the squareness of the bed with the rest of the frame.
If you find you're having to re-level often, something is wrong with your printer. You may have play in the Z-axis/gantry - on Ender 3 style printers with only one side driven, the undriven side tends to wander up/down unless you get everything tensioned perfectly, and this manifests as apparent loss of leveling. You may have adjustment wheels working themselves loose (watch the end to see final findings) that mess up your leveling (I've had good luck mitigating that with this add-on). You may have an unreliable endstop switch (mine was acting up recently after years of use, and replacing it fixed the problem entirely).

Also platform thicknesses vary a bit, especially if you have different platforms or sometimes use tape and sometimes not.

Why? To provide a 2D  plane of the build surface that is parallel to the nozzle at the whole print area (usually the X-Y plane). If not, this leads to problems in getting the first layer to adhere to the build surface (see the many questions on "leveling" on this and other sites).
Please note that for good quality printers the tramming is performed very seldomly. My CoreXY home built and my Ultimaker 3E are trammed once every few hundred prints! Usually as a result of misuse like in pulling of the print when it is still sticking too much to the plate. It is the quality of the printer and the handling of the user that determines how often this should be done, but it has to be done at least one time to establish that 2D plane.

In addition to the answers above, you can have perfect levelling for one filament that doesn't work with another.
So for instance my normal PLA works perfectly at one bed level, yet if I change to the generic silk I have it won't adhere unless I change the bed height fractionally. The differences are tiny but are make or break changes.
Copper PLA filament is slightly different to both in terms of getting a nice first layer.
ABS also requires slightly tighter bed levelling on my printer.
So while I rarely change bed levelling, I do if I'm changing filament. But quite often I don't bother with the whole levelling thing, I just adjust the knobs while the skirt is printing.
This is from my experience, your mileage may differ.