text:
Transparent Plastic
Is there any commonly printed plastic which I can buy that might be transparent to UV light?
I wish to print a mould, then pour in my plastic which requires a UV light to activate the curing process.

Well, there are plastics which are transparent to visible light, have you tested these? ABS sheet is easy enough to buy. This is more of a chemistry question than a 3d print question...

Have you tried printing with Form labs clear resin ?
( This is assuming you have access to a desktop SLA like the Form2+ or Form 1 )
The printed part itself gets hardened after exposure to uv light and actually can increase the life time of your mould .
I have been using the Form labs Form 2+ a lot recently for small moulds and casting them with Polyurethane . They work amazing and the precision of the mould is high due to 0.05mm layer resolution that is achievable .
Once hardened the UV light easily passes through it and does not degrade the part at all .
Here is the material data sheet
https://formlabs.com/media/upload/Clear-DataSheet.pdf
You can easily get a clear resin print done through a local 3D printing service bureau that you can find using 3D hubs .
Prices for printing on a formlabs are comparable to FDM 3D printing , it really just depends on your supplier .
If the above doesn't cut it then ,
Use  DSM Somos® WaterClear Ultra 10122 , please check below link and corresponding data sheet for technical specifications .
https://www.dsm.com/products/somos/en_US/products/offerings-somos-water-clear.html
This can only be printed on a 3Ds systems viper , Envision tech preform series or other industrial 3D printers .
Again you can head to 3D hubs or call up the closest industrial 3D printing service bureau and ask them for the above material . They should be able to hook you up easily .

It is easy enough to test materials.  First, get a UV flashlight or laser, and find some object that the UV light will make glow.  White paper or white cloth will probably work.
Next, for a material you wish to test, print a "transparent" wall as think as you need.
Shine the light through the transparent wall.  If the wall glows, it is interacting so heavily with the UV light that it probably won't transmit UV light.  The light will probably be scattered, since "transparent" material is rarely glasslike when printed.  If the test object you found in the first step still glows, the wall is transparent enough.  If it doesn't, try the next material.
There are transparent forms of PLA, ABS, PETG, HIPS, and nylon.  Probably other materials, too.  Try them.

Printing almost transparent products is actually quite possible, I was amazed to see the quality of the parts, see e.g. https://learn.colorfabb.com/lets-make-something-clear/.

UV crosslinking is VERY wavelength specific. Just because one material appears to allow passage of "some" UV wavelength relatively unimpaired does NOT mean that it will transmit the proper photoinitiating wavelength with adequate fidelity.

Agreed.  Perhaps i should have asked the OP about specific wavelengths.

This is more of a Chemistry question, but seeing as we love 3D printing with exotics, here are a few.
Topas olefin copolymer
From the mfr description page,

TOPAS cyclic olefin copolymer, or COC, is an incredibly pure polymer -
in fact, it's purer than most grades of medical glass. Unlike glass,
it has a non-ionic, inert surface to minimize reactivity,
denaturation, agglomeration, delamination and other traditional glass
concerns. And when it comes to maintaining purity, TOPAS medical grade
plastics can be sterilized via all common methods. Leachables and
extractables are extremely low. Reduce risk and increase performance
by maintaining the benign, protective environment that TOPAS COC-based
devices provide.
Medical grades of TOPAS COC are extremely clear, and are optically
suitable for replacing glass in many applications.

I'm not sure of its melting point, or of the speed of solidification (which affects extruder rate, motion etc).
Recommended at this Chem.SE question, PMMA and others
edit
Because answers there have links of their own, I"m not repeating the various technical leads available there.
Now you will have to investigate their melting points and flow rates, etc. to see if these can be coerced to function in an extrusion printer.

This is awfully close to a link-only answer. What is "Topas olefin"? Can you print with it? What does the linked Chem.SE question say?

@TomvanderZanden  printability remains an experiment for someone to investigate, so far as I know.   Given that it's possible to print with clay,  it would seem to be "just" a matter of temperature, nozzle size, feed rate, cooling enhancements...

This answer remains low quality in my opinion. It seems hastily written (you haven't taken the time to write out "manufacturer" but for no good reason abbreviated it to "mfr"). The bit of text you copied from the manufacturer page seems rather irrelevant to the question (it lists random benefits of the product, but it doesn't even mention transparency to UV, for example). It seems like you just googled "UV transparent plastic" and copied the top two results into your answer while adding no new information or insights and are basically telling us to figure out the answer on our own.

@TomvanderZanden anyone who decides to bitch about abbreviations has psychological problems far beyond my capability to rectify.  Delete your account.

Whoa, steady on..! That's not a helpful comment. Please try to keep it cordial and not scare people away. I haven't down voted you, but Tom does have a point.  This answer doesn't seem up to your past usually high standards Carl, and seems rushed, to be honest. Take your time and edit it when possible. Thanks :-)


text:
Plug sdramps module and Anet A8 LCD together into RAMPS smart adapter
I want to upgrade my Anet A8's motherboard (the stock one is broken anyway, see: Anet A8 reading 739°C from the extruder thermistor!) to the RAMPS 1.4, without having to get a new LCD/microSD module. I am thinking of getting both a smart adapter and sdramps, then maybe plug the sdramps and the stock Anet A8 LCD into the smart adapter, but I am not sure whether the sdramps module has a different pinout than the RAMPS smart controller, which is what the smart adapter is made for.
Can someone confirm whether they have the same pinouts or not, or give me some alternatives to my idea?

I've seen the other way around where someone connects a rep rap LCD to the board: https://www.thingiverse.com/thing:2103748

The link above gives you information on the pin layout which you can compare to the layout on the RAMPS. You know there is a 1.6 version which has improvements on MOSFET cooling and more copper in the traces?

@0scar it is easy the other way around, but I want to keep the stock LCD in order to save some money.

@0scar 1.6 has SMD fuses, which are much harder to replace than removable fuses, or even through-hole soldered ones.

The Anet A8 uses a simple LCD with 5 buttons, the problem is that the buttons do not use digital pin signals, instead analog pins are used. Based on the pressed button, with corresponding resistance the firmware knows which button is pressed. The RAMPS smart adapter uses digital pins, so the Anet LCD is not compatible with the smart adapter, you may wan't to opt for a cheap Chinese 12864 LCD smart controller, they are about $8, they are compatible.

The topic Connecting (Anet A8) 2004 display to MKS GEN L shows you to hook up the Anet A8 LCD to a RAMPS board. You do not use the smart adapter, instead you use AUX2. You only have to change 2 wires (interchange them on AUX2) and you will be able to use the display. The reason you cannot use the smart adapter is that the 5 button display requires analog pins, which are not available on the smart adapter, but are available on the AUX2 header.

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

authors: เต้ สามแยกหัวหิน

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

sort: votes


text:
Temperature offset on Wanhao Duplicator i3 Mini
I'm trying to print with PLA on a new Wanhao Duplicator i3 Mini. In regular temperature settings (200-210°C) the printer underextrudes and the extruder motor skips, which led me to suspect low nozzle temperature. Increasing the temperature to 225°C indeed allows the printer to print normally without any problems.
What can be the cause for this? Is it a faulty temperature reading? What is the way to fix it?

It's very difficult to diagnose 3D printers without physical access to the machine, but here's a few possibilities that come to mind (several of those may contribute together to the problem).
The temperature reading is poorly calibrated or defective
This means that the actual temperature is lower than what displayed.  You can verify this hypothesis by using an IR thermometer or replacing the probe (on some printers the heat probe on the bed is the same than the one on the hot end, so you don't need to buy a new part).
The batch/brand of filament you have has a higher melting point than expected
So: the filament is supposed needs to be extruded at 225°C, but the label (or simply your assumption from having used other spools of filament) says otherwise.  Just use that temperature and be happy.
The teeth of the extruder gear are worn
Within limits, the hotter the molten plastic is, the runnier.  This means that at 225°C it will be less viscous than at 210°C and will strain the extruder motor less.  If the gear of your extruder has worn teeth that won't "bite" deep enough into the filament, they will eventually slip when reaching a certain torque.  The teeth of an extruder wheel should feel well defined under your fingers, if you are in doubt about them not being sharp enough, then they probably aren't, as the feeling is quite distinctive.  Replacement gears can be purchased online very cheaply.  EDIT: re-reading your question I realised you wrote that the motor skips, so this and the following point may not be the case for you, even if sometimes - but not always - slippage makes a similar noise to skipping.
The spring of the extruder gear is weak
See above, but here the root cause of the slippage is the extruder gear not being pushed hard enough into the filament.  This is caused by the extruder spring being too weak.  Most printers have some mechanism to regulate the tension of the spring.  A DIY method is that of adding a stack of washers (or a custom printed cylinder) at one end of the spring in order to "pre-tension" it.  Otherwise again: spring replacements are extremely cheap.
Your part fan is blowing on the nozzle
The temperature probe measures temperature at some place in the heat block, not the nozzle.  If your part fan is blowing too high, the flow of air may be cooling down the nozzle, instead of the extruder part.  You most definitively want to avoid this by repositioning the fan or printing a custom fan deflector (the latter is a classic among mods).  This is an easy-to-diagnose problem as most slicers allow you to turn the part fan off.

I've ruled out 2 as the filament indicates 190-210 melting point and 3 and 4 because it is the motor that skips not the gear (which has perfect traction). So it's 1 or 5.I don't have a probe at hand so I'll have to find another way of measuring temperature I suppose

@insys - Mind that mine were only the first ideas to pop to mind, there are other possible causes, I guess, that I haven't thought to! :)

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Extruder clicking Tronxy x5s
Whenever it start printing the extruder starts clicking, I tried adjusting the voltage with no luck, it's still clicking. And it doesn't extrude a lot of plastic sometimes it even stops extruding but the extruder is still turning. Can someone help?

please see this answer  https://3dprinting.stackexchange.com/a/3205/9730  and use search box as you can find many answers for that particular problem

Possible duplicate of Extruder clicks

Probably temperature too low or nozzle too close to the bed, as per @profesor79's possible dupe.

The clicking you are hearing is either the stepper motor skipping steps or the hobbed gear losing grip on the filament.
Either way, it means that the filament opposes an unusually high resistence to be pushed forward.
A key information to be able to diagnose your problem is whether the clicking is on the firsts couple of layers or throughout the print.
If it is only for the first 1-3 layers the problem is likely to be the printing bed too high (or deformed), so that the nozzle touches it and the bed acts a "lid" on the nozzle preventing the molten plastic to get out.  If this is the case, adjust the printing bed to be flat and level (and the nozzle at the right height when homed on the Z axis.
If the problem persists throughout the full print the problem is likely to be related to one of the following:

the extruder not managing to get a firm grip on the filament (worn teeth, slack spring, ...)
the stepper motor being underpowered (this seems not to be your case, given that you have already adjusted the voltage)
a clog, adhesion, or restriction in either the bowden tube or the extruder, for which the best solution is disassemble, inspect and clean (eventually changing the bowden tube if it has been deformed).

I swapped the stepper motor with the x-motor and i put new filament in the extruder because the old one was damaged by the teeth of the xtruder and now it goes through the tube more easily. I also added a little washer between the spring and the casing of the extruder so it's a bit more tight. Now the clicking is gone but the filament starts slipping, so the extruder is turning but the filament stays where it is and it doesn't extrude a lot.

I also have this problem with the X5S, and it's not just on the first layer (which is sometimes finicky depending on the levelling). I've narrowed it down to a few things, and I've also noticed that it varies based on the print.
Possible Causes (and a suggested solution for each):

Bad quality hotend assembly: My X5S has a teflon-lined hotend, and besides that I don't like the rather small heatsink, mine came such that the bowden tube acts as the teflon lining, ie the lining and the bowden tube are the same piece. Already not a great design, but the implementation is slightly worrying. I'd recommend switching the hotend for a genuine E3D, I myself am planning on getting a Cyclops+ Aqua, which will be sure to resolve any existing issues.
Bowden tube is iffy: I'm not sure about this one, but I've noticed quite a bit of resistance in the bowden tube while loading filaments. I think this is causing excessive force on the Extruder motor (which I've noticed heats up quite a bit more than the other motors, to the point where I've added a heatsink to avoid possible damage). My solution is to swap the teflon for the blue Capricorn tubing from Trianglelabs.
Extruder setup isn't that great: As I mentioned before, the extruder motor tends to heat up a bit, and I just don't like the implementation of the extruder gears. I'd recommend switching this setup for a different one, if possible.
Print temperature and speed: I've noted that when I increase the temperature and decrease the speed of prints, the clicking reduces in frequency, but it does still occasionally click and my prints turn out horribly. This might be pointing to an issue with either extruder calibration or the flow rate during a print, as mentioned by other people here.

Cheers!

Regarding #1: it is actually BETTER to have the lining be the same piece as the tube as fewer parts that could move in the filament path is better. But indeed a full metal hotend is better. #3 what kind of extruder setup? #4: this is a partial fix for such behavior, yes.

I have the TronXY X1, which uses the same extruder and firmware design as the TronXY X5. The clicking does not come from Voltage, but most likely a wrong set up of steps/mm or a lightly clogged nozzle.
Quick and dirty steps/mm

Start a print that you know clicks.
wait for the clicking starts (it comes from the extruder pushing against resistance and jumping back a step)
Go into Configuration > Extruder > Steps/MM
alter it down a little, listen if the constant clickig stops, alter again if needed.

Now, you need to make sure not to get into underextrusion doing this "on the go" fixing, and you really should calibrate your extruder.
Proper calibration
To calibrate your extruder, you could follow Thomas "Tom" Sanladerer calibration video or this rundown:

Move the printhead to a position where it can extrude freely.
heat up your hotend
load the filament (or have one loaded)
take a filament spool and make small marks on it an increment from the extruder's intake - for example with a CD marker. Tom uses 100mm (Ep for Extruded planned) for the calibration and adds 50mm to compensate for overextrusion, so places the mark at 150mm (L for length), allowing to calculate a compensation into both directions.
extrude 100mm of filament - it is advisable to directly send the G-code via a program here to use G92E0 to 0 the extruder and G1E100F90 for the extrusion
Measure the distance of your line to the extruder. Let's call this value R, for "Result position"
Now, we calculate Et (extruded truely): L-R=Et

Now, we have a length to compensate for. But what value we adjust? Steps/mm of course!

Either go into Configuration > Extruder > Steps/MM or send M503 to get the steps/mm from the configuration
lets call this value S for Steps/mm

Now, let's calculate the Sa, "Steps/mm adjusted":
* S*Ep/Et=Sa
Now, let's get it into the machine!
* Go into Configuration > Extruder > Steps/MM and adjust manually
 * make sure to save into EEPROM
* alternatively, send M92ESa , replacing Sa with your calculated value
 * Then, send M500 to store the value in the EEPROM
* third alternative: change the firmware configuration and reupload.

I have an X5S and quite frankly, I never got it print properly because of these persistent issues. Thank you for the most excellent comments and suggestions. Lots to investigate.
I added an anycubic glass table but that takes longer to heat up. But i am unable to get adhesion on the first layers and the clicking kicks in shortly thereafter. I wonder if this thermal latency might imply a colder bed on first layers. I have tweaked the leveling so many times it is not funny. This is pointing to friction in the Bowden delivery system and the extruder itself.
I got an E3D that I must adapt. Too bad i cannot print those parts!
I have noted also a great variety of results from different printer filaments brands as well.

Hi Paul and welcome to 3D Printing.SE! This is not an answer, this is a comment, or a start of a discussion. SE sites are not forums, just questions and answers. Please take the [tour] and read [ask] so that you can formulate a good question to help you solve your problem. Most, if not all, issues you raise have been answered here before. There is even an answer for printing parts if you cannot print yourself!

On my X1 (same extruder & carriage),when did swap for an e3D hotend, I used the adapter of https://www.thingiverse.com/thing:2203334 - I did print the piece n a "unmodded" machine.


text:
Weird underextrusion in vase mode?
It's my first time printing in vase mode, and I noticed my printer underextruding badly. The settings have not been changed from default vase mode settings in slicer, and earlier I was printing non-vase mode and the prints came out fine. Layer height is 0.2 mm and perimeter width is 0.3 mm.

Did you check for the most obvious reasons like friction on filament unrolling, clogging, layer height, etc.

@0scar Yes, I stopped the print and used manual control to extrude filament. It came out completely straight and normal looking. Layer height is set to .2.

PLease let your print run for at least 10 layers so we can see what happens when the system gets away from the bed.

It looks as there are more than 10 layers already.

Finding the cause of under-extrusion is very hard as a lot of parameters of the print process can influence this. There are some nice websites that describe these problems in detail. From your question it is unclear what you have done to solve the problem, or if you have printed products after the vase mode and shown us a picture of that (this eliminates a lot of possible problems).
A nice overview is given by Ultimaker, but other sources may help you to find the root cause, e.g. Simplify3D. If the issue is related to the filament and hot-end, Printrbot, Trideus and Rigid.ink may help you solve the problem.
Important is to isolate your problem! Not knowing what printer you have, your printer has (or potentially has) the folowing modules/elements that may be causing the underextrusion:

the slicer (highly suspicious),
the material/filament and the spool holder (suspicious),
the extruder or feeder (suspicious),
the hot-end (suspicious),
the Bowden tube (suspicious if you have one).

Note that to find the root cause you should tackle this by elimination, this way you make sure that certain modules are not causing the problem. Also keep in mind that the vase mode prints a single outline/perimeter shell and won't make any retracts (so the Z axis will continuously rise), in which defects are shown instantly. Please, take a close look at your normal multi perimeter print.
How to fix under extrusion!
Under extrusion is probably one of the hardest to find the direct cause as there are so many variables to consider. Please find below some of the variables that can affect your printing quality marked in bold face.

Material and material settings

The material you use needs to be resembled correctly, so it is important and easiest thing to check first if your print is suffering from under-extrusion due to incorrect material settings. The material settings in your slicer (or the material profile on your printer for the more fancy printers) should match the material you are printing. So please check the filament diameter with a caliper and measure the diameter at various points; take the mean diameter of at least 3 to 5 measurements. Furthermore, temperature is also an important factor; too low temperatures will cause that the extruder has to push harder as the material is less viscous due to the fact it is not heated properly. Note that this can also happen if the flow of the filament is too high and the heater cannot keep up. It is these high pressures that cause the under extrusion as it may not flow fluidly. In contrast to too low temperatures, too high temperatures, can also cause problems. Very high temperatures can change the structure of the material, this is often referred to as carbonization causing deposits (clogs) in the nozzle. A word of advice, Please check your filament spool/box (or sometimes a paper in the box or bag) for the proper temperatures.

Next to the temperature, other important material settings are the print speed, the layer height and the nozzle size as these properties further define the rate at which the filament volume is deposited. For instance, a too high of a volume flow not only can lead to the previously mentioned cooling of the nozzle, but also is limited by the diameter of the nozzle, you just cannot push more through the nozzle is capable of as the friction will increase (the smallest opening in the system determines the maximum rate of volume flow). If you do, this will lead to under-extrusion. To find the optimum between speed and temperature, a good balance between these needs to be found. A typical way to do that is by the use of printing calibration temperature towers, preferably at various speeds. To print faster, you need a higher temperature, but printing at lower temperatures because of overhangs, you might need to decrease the speed to get a proper extrusion (and maybe also part cooling).

Don't just focus on the hot end part, also take a closer look at the filament spool itself, or better, how the spool unrolls. Is the spool of filament unrolling correctly/freely without a lot of friction (does it make sharp bends, or does it go through a tube having friction from its container to the extruder), or is the filament not correctly wound causing tangled filament (which create a lot of friction preventing enough material to be transported to the hot end) which could stress the extruder.

For some materials that are hydrophilic (they attract water and trap it in the filament, this happens e.g. with PLA, PVA, Nylon and maybe even more) printing the filament with contained water, the water will turn into steam causing bubbles in the deposited filament and interfere with the flow deposition. This effect sometimes makes a distinct sound like popping bubbles. Always store your filament in a sealed container or bag and use desiccants bags. Moisture can cause damage to the printer as the filament swells when taking up moisture; this could lead to various jams. Last but not least, filament with moisture in it has less mechanical properties after printing than dry filament (up to 33% less).
The extruder/feeder and Bowden tube

The extruder/feeder pushes or feeds material into the hot end, or into a tube (called Bowden tube). Under-extrusion caused by the extruder is typically characterized by the fact that filament is not properly fed to the hot end as a result of too much friction in the tube or hot end, too less grip on the filament or filament grinding (the extruder gear 'eating away' the filament). Too much friction could even cause your stepper to tick or click, basically turning back as the pressure on the filament exerts so much pressure that the stepper is rotated back; increasing the feeder tension on the filament (by adjusting the screw on the extruder/feeder would fix that). Grinding is easily spotted when removing the filament; it will clearly show that the gear has worn away circle shapes. Furthermore, filament taken out of the printer should show visible marks on the material as imprints of the extruder gear, if completely smooth, the feeder tension is too less. On the other hand, too much tension on the feeder could flatten the filament, which leads the previously mentioned grinding effect. If you encounter grinding, please assure that you clean the extruder by removing the filament powder and chunks the grinding produced and recheck the extruder/feeder tension before continuing printing again. Be sure that the grinding particles have not entered the Bowden tube as it causes friction. Cleaning them regularly or replacing them once a year is advisable depending on the usage (or once every x kilometers of filament). Furthermore, larger diameter filament (2.85 or 3 mm) can cause additional friction (in the Bowden tube or the extruder/feeder) as towards the end of the spool, the filament is wound tight along a small diameter spool center causing strongly bend filament that exerts pressure as it acts like a spring creating friction at the walls of the tubes.
The hot-end

The hot end can also be a culprit for under-extrusion. Partial blockage of the nozzle as a result of carbonization (buildup of carbon or carbonized material in the nozzle). Even left over material from previous prints inside the nozzle (unflushed residue) may change the volume of the nozzle when the material you printed before needed a higher temperature than the current you're printing. Also try to get good quality filament, it might be that the quality is just not constant for the whole spool. Too clean the inside of the nozzle, a few techniques exist to remove blockage. By performing a "cold pull" or using the atomic method. Both techniques rely on the mechanism to insert the (cleaning) filament when it's hot and remove it quickly at a lower temperature. E.g. see here or here.

You are printing walls of 0.3 mm with a 0.4 mm nozzle (25% contraction). This might fall in the category of insufficient volume flow. The wall width is less than the nozzle diameter, so it needs to contract. Either way, the volume is too less and may be dragged along until it is flattened. You should increase the wall width, maybe even a little more than 0.4 mm (although that might not be necessary, see edit below).
To support this, the next table shows the volume calculation for the filament (based on extruded cilinder shape), the first row is the volume you need to fill the 0.2 mm layer height (0.025 cubic mm), the second is what you extrude with a 0.3 mm width for a 0.2 mm layer (0.014 cubic mm). From this latter value you can calculate the layer height for a 0.4 mm diameter nozzle to be about 0.11 mm, clearly not filling the gap.

Edit:
To further support this, please read this test.
The extrusion width versus strength show the optimum strength when the nozzle extrusion width equals the nozzle size.

I'm almost 100% positive the problem comes from somewhere in slicer. Before the vase mode print, my extruder worked perfectly and I was able flawlessly print some models. During the vase mode print I even stopped it and used manual controls to manually push material through the hot end, which worked perfectly.

What is the size of the nozzle? E.g. printing 0.3 with a 0.4 nozzle is not optimal.

Nozzle is .4mm diameter.

@patrickjackson I have updated the answer for you, I strongly suspect that your volume flow is not enough (so indeed a slicer setting as you suspected)

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


text:
Weird Movement and not homing
https://photos.app.goo.gl/O6yPf3sDeV1yhS0C2
I tried to illustrate my problem in the videos above, two of them show the weird movement and the other shows me clicking on the home button repeatedly.
Some Info:

Marlin 1.1.8 or 2.0.0 (same problem in both)
Robotdyn RAMPS 1.4
0.9 angle stepper motors
DRV8825 drivers configured at 0.8V Vref
Anet A2 Plus stock for all the rest

is that freshly assembled device?

It might be helpful to know which are the result of a single movement command, and which is the response to successive home requests.

It might be helpful to know which are the result of a single movement command, and which is the response to successive home requests.  Some words about what is weird could help, so that an answerer needn't access the video (although the video is great information to attach to your question).  From the video, it looks like movements on two axes are not coordinated -- only X or Y moves, but not both at the same time.  I won't try to answer your question, but your observations will help bring the right answer.  You are closest to the problem, and have eyes, ears, and fingers on the problem.

The problem was the logic of the endstops that were reversed

This is not a matter of effort but instead it is a matter of what's right or wrong. The other post is really well written but it doesn't address the problem faced.

As far as I can see on the attached videos your homing movement is reversed.
as per Marlin, the homing for X shall move towards the left side and for Y to the back of the printer.
That could occur when: cable connectors to stepper motors are reversed, or the motor is assembled the other way (you can set reverse direction in Marlin)
The other issue is steps/mm calibration need to be done see source below.
The high pitch in the video could also point that the drv8825 is shutting down the movement as it is overloaded.
please also check that for vref

Configuring Vref In order to measure Vref you first need to turn on
  your printer as you normally would. If you only connecct using USB,
  but not external power, you get a wrong reading.
You need to turn on your multimeter and set it at 2v. Put the red one
  on the potentiometer and the Black one on the Gnd pin. Both are marked
  on the images here.
Before starting this I read they come with a very high vref setting,
  and it is recommended to start around 0.5v Vref. After measuring mine,
  I can confirm they come with a very high initial setting. Mine both
  came at 1,65v or so! - Yours might be different, which just underlines
  the importance of doing this.
Contrary to normal potentiometer usage, the ones on most copies/clones
  of DRV8825 are lowered by turning clock-wise, so that is what we will
  do, to we hit 0,5v on each. - A quarter of a full turn lowered it to
  0,7v, - after that it goes very, very rapidly down, so aim for the
  quarter of a turn + a tiny tad more. If you buy your DRV8825 directly
  from pololu.com the Potentiometer are dialed up by turning it
  clock-wise:

source

Hi, I've just solved the problem, I found out that the logic of my endstops are reversed. That solved everything. Yes, I have to tune the steps per mm yet. However my Extruder motor does not move, even above extrusion min temp


text:
Which 3D design softwares make multi-material amf or other design files that slic3r will slice?
I'm looking for suggestions for 3D design software which support designing multi-material parts.
I will be printing on a multi-extruder machine based on RepRap firmware.  The printer will handle the files when given a proper g-code file.  Slic3r will produce a proper g-code file given the right input.  STL seems to be single-material, so I am looking for something like AMF files, or any alternative.
My question is, what is available for 3D design software which will produce a geometry file which slic3r (or some other slicing software) will properly process?  I'm not asking for opinions on which software is best.
I believe this is my first question in any StackExchange forum, so if I have trespassed on community standards, it was not my intention.

Cura merges 2 STL files, and can be printed for 2 materials. Like printing PLA or nylon with extruder 1 and PVA with extruder 2.

I'm still waiting hopefully for my Kickstarter kit to arrive - it's a resin-style printer which supports rotating among up to 4 different color reservoirs.  But to your needs - there are multi-head extruders which will handle any material, as Oscar says.

My problem isn't the extruder or printer, it is finding a workflow that allows "easy" design of multi-material parts, and "easily" rendering those parts on an appropriate printer.

A Scriptable Process for Generating Multi-Material STL Files:
I am now using interactive CAD software to define the more complex features of the object I am printing (in the current case, clock faces), and then using OpenSCAD to do the boolean volume operations.
To print the composite object, I need three STL files, one for each material I am using.  The three parts are the clock body, the translucent optics to conduct the LED lights, and the clock numbers.
I need:

one STL for the body minus the LED optics and minus the numbers.
one STL for the numbers minus the LED optics, and
one STL for the LED optics.

The CAD package supports the operations, but every time I change anything, I have to jump through several hoops to combine the three parts, manually and recreate the three objects.
I had used OpenSCAD to make the optics and the numbers, and they were never in the same coordinate system as the clock body from the interactive CAD package.
So, I scripted it and used OpenSCAD to read the clock body STL and being it into OpenScad.  I transformed it into the common coordinate system.  I then did, one by one, based on a command-line parameter, the boolean operations, rendered the result, and exported the resulting STL file.
When I read the three files into PrusaSlicer, the lined up perfectly and everything worked simply, without and precision hand-eye coordination, and with no drama.
Scripts and command lines work for repeatability far better than squint, drag, and guess.

That's a huge step! almost 3 years, but good you came back to this!

You do not necessarily need a specific design tool, you can use any tool you want to create your multiple material product. It is the slicer software that manages the materials by assigning the correct extruder. E.g. Cura is able to join 2 STL files that fit together and assign each part a specific extruder and thus material. Please read more here for instructions

Thank you @Oscar.  I have the Cura instructions you linked.  So far, I have been using RepetierHost and slic3r.  I will install Cura tonight.  It seems that the key step is the "merge models" step, and coming to understand the constraints on merging.  I'll try answering my own questions with Cura directly.

Hi @Oscar.  The setup probably wasn't right, but I tried "combining" three nested parts, with the thought of printing each in its own material.  Using Cura, I could add the three STL files to the build area.  I could not position them nested within each other (even through the were non-intersecting).  Cura would move them apart to correct my error.  When I tried the "merge" option, it dropped them on top of each other so they had overlapping walls, and I couldn't adjust their relative positions.  I will need to make a better test case.


text:
Is there any public and reasonably accurate 3D scan from a Cray-2 computer?
I'm thinking about building a Cray-2 inspired cluster. I'm concerned about the exterior housing modules, proportions and panels.
Has anyone done a good 3D scan of one?

I believe that, with the last changes, the question has more objective answers and, while not one of the topics described in https://3dprinting.stackexchange.com/help/on-topic, it doesn't fall into the "bad question" criteria either.

you did nothing to change the scope or target of the question rbanffy: Your question is "Where to find a model of X", which is not Troubleshooting, Repair, Best Practice, Technology, Material, Capabilities, how to design your OWN parts or something about print services. It stays off topic.

"The following topics are merely suggestions, topics are not necessarily limited to the following and all topics are subject to community discretion" (from https://3dprinting.stackexchange.com/help/on-topic)

LMGTFY, etc. etc.   Depends on the amount of detail you want.  A cheap starter: here, or here or irrational fruit

None of these is a Cray 2. LMGTFY, this is what a Cray 2 looks like https://en.wikipedia.org/wiki/Cray-2#/media/File:CRAY-2_IMG_8915-8913-8912a.jpg


text:
Filament clogging just above feeding tube - Duplicator 6
I have this clogging problem on my 3D printer that I am having a really hard time to solve. I am a hobbiest so in no way am I a professional with regards to 3D printers. I also know that this is a popular issue and I have tried a lot of the proposed solutions (going through a lot of PLA filament and failed prints) to no avail. I will try to describe the problem and what I have tried to solve it.
First the issue:
This shows how the filament clogs. The next image shows the assembled printer head for reference.:
This is how the print looks when it fails:
I have tried the following:
- Adjusting the temperate between 190 up to 220 for the PLA filament. Everything trying a print with it.
- Doing a thorough cleaning of the nozzle (Acetone soak, wire brush, guitar string etc.)
- Checking the Teflon pipe inside the tube if it is clear and ensuring that the edges allow the filament to pass through.
- Check if the cooling fans work well to ensure cooling of the whole assembly (they work, they aren't jammed etc.)
- Dissambling the printer head and putting it back together.
I have printed with the printer before without a problem. I printed PETG a few times to get that working and the results were decent. When I returned to PLA this issue started and no matter what I change on the profile it won't work. I have tried adjusting feedrate, flow rate, retraction amount and speed, temperature, fan speeds to name but a few things.
I have a Cura profile I can upload if that will help. Any advise would be much appreciated. I have been struggling with this for a while now and really need some options.

It looks at though your PTFE tube has deformed as a result of over-temperature/heat creep. How is that part cooled/is the cooling working?

Heat creep was the most obvious answer I could find on the internet but it has not been a problem previously. I did check the PTFE tube and the filament can pass through it comfortably. I also ensured that the edges of the tube is position correctly in the nozzle (correct length, etc).
How would I know if the tube is deformed?

It's probably worth keeping some spares and changing the liner tube any time you take the extruder apart -- they are quite cheap and surprisingly easy to damage.

Sometimes the filament quality itself could be the culprit. Have you tried printing with a different spool of PLA?

Hi have not tried with a different spool. I will take a stab at that and let you know. Any idea on what else I can try as well? Can it be a setting that is just completely wrong?

I printed the same model with the same settings with some of my old, cheaper filament and the print actually finished. So it is the filament. What makes wonder then, what is it about the new, better quality filament that stops it from working well in my printer?
Is it the diameter of the filament?
The temperature your print at?
How can I get my printer to print with this new filament?

Sometimes other additives/color in PLA can cause strange jams and print quality issues. When does your filament clog like you showed in the picture? Is it after a retraction move?

Yes I think so. Im changing up the filament to test what has what effect.

that looks like heat creep.
heat creep is the result of in too much heat in the hot end creeping its way into the cold end. and results in a gradual clogs mid print.
to combat heat creep you need to sink that heat elsewhere and dissipate it.
this is where a heatsink and fan come into play.
the heatsink should be in direct contact with the throat mount/clamp, giving the heat more space to dissipate, and that dissipation is aided by the fan.


text:
Prusa i3 PLA fails to stick to first layer on curves
I have been searching around on google and not found any answers to this dilemma. I am using a Prusa I3 printer with PLA, trying to print horseshoes for the company I work for. They are for model horses, so quality is fairly important. I seem to have gotten all the settings dialed in just the way I want them and for the most part, the prints come out fine. There is however one annoying thing that keeps happening. When the filament is going around the curve of the top of the horseshoe on layers beyond the first, the filament does not follow the curves of the first layer. But its not every time. It seems like it is just the 2nd or 3rd Layers that are doing it. I have adjusted the flow rate, the speed, the layer height, temperature, and nothing seems to get rid of this irksome issues. I can of course provide more in depth details, and am including a pic of what i am getting. Any Ideas?

layer height? filiament diameter? temperature?

I'm voting first layer too high off the bed.  Also try blue tape not masking.

1st layer height is .3, the rest are .1. i run the first layer at 210 and the rest at 205, bed at 70 throughout. Filament diameter is set to 1.75. the first layer seems to stick perfectly and further up the layers go just fine.the thing is, the nozzle follows the curve, but the PLA just stretches out until it sticks in the center. Also, blue tape is on the way, that's the stuff that came with the printer.

@jeremiahharless the first layer height should be at least 50% of nozzle diameter to allows good adhesion and speed between 50 and 75%, your masking tape must be free of dust after sanding.

UPDATE: I found perimeter settings in Slic3r and slowed down the external perimeter  and small perimeter print speeds to 25% on the gcode and set the printer itself to 15 percent. the result was a complete cure, but double the print time. I am going to keep upping the print speed on the external perimeters a little at a time to find the sweet spot between speed and adhesion. I will post my results once I have it dialed in.

It could very well be that your print speed is too high (starting from the 2nd layer) for the motors to keep up comfortably. Try reducing the print speed to perhaps 75-80% of what you are using to see if it addresses the issue. You should also check you model to make sure there are errors in the STL. Sometimes such mesh errors can cause funny things to happen. Do you see the irregularities in the print preview at all?

I have set the overall print speed down to 15% because this printer prints way too fast to begin with. I can try reducing it further, but the slicer software I am using (Slic3r) only allows me to adjust the first layer print speed. It's also frustrating that it is just the 2nd through maybe 4th layers that do this, and the rest look fine. I checked the preview in Slic3r and nothing looks out of sorts on the model, but any horseshoe model i print suffers this on the curve. Could it be the slicer soft itself?

@jeremiahharless Slic3r allows to set print speed for first layer and normal layers, try to set to 60mm/s instead 80mm/s of default settings. On display control you can reduce or increase the speed as you need, some times is needed to reduce less than 20% or more.

I got the same problem on a Ultimaker 3 with Cura. The problem was, that there is a hidden option for the initial layer. By default the first layer is set to something around 130-150 % of the normal layer height.
So if you set up 0.2 mm the initial layer will be printed with 0.27 mm and this can cause problems. After setting this initial layer height to also 0.2 mm the print stuck really good at the bed.
I also made similar observations on my own Anet A8.

Is that printed on to tape? It looks very uneven. I'm guessing this is general bad adhesion and its just showing up best when going around curves.
If you print onto tape, try putting it down with a squeegee, so it's absolutely flat and level with no creases or bubbles.
I've personally had very little luck printing onto masking tape.

I t looks bad because thats the 15th or so print on that tape. It's the stuff that came with the printer. First layer adhesion is almost too good, its PLA on PLA in the 2nd and 3rd layers that seems to be the issue. I have a Davinci AIO that prints ABS and doesnt seem to have this issue on curves.

Interesting. Cooling coming on after the first layer? Maybe too cold to bond. Might be worth doing a few small tests with a range of temperatures, at very low speeds (say around 40mm/s). Then try bending them until they break. If they come apart at the layers easily: too cold. Keep going up until it snaps as one piece.

Using a combination of external and small perimeter speed settings (Slic3r), as well as slowing down the overall print speed on the printer itself, I was able to get reliable curves on the horseshoes.  I have also downloaded Cura and am playing with the advanced print options that it comes with.

possible solutions
1) try and increase the extruder temp by 5 degrees for the first layer and see if that helps
2) disable coolign for the first few layers.
3) try adding some PVA glue (washable school glue or elmers washable gluestick) to the masking tape
if the above failed set a z offset (in slic3r the z offset is in the printer tab)
3a) if you manually level with paper and have access to a caliper. change the z offset in your slicer, to a negative of whatever you used to level.
3b) if you manually level and you don't have a caliper set the z offset to -.1, if you used something thicker like a business card try -.15 or -.2


text:
Support material first layer adhesion issues
I am quite new to 3D printing, and having difficulty printing  first layer of an object with support. The object has a few curved surfaces that touch the print bed, so not a big starting foot print.
I  am printing on a genuine Prusa i3 mk2s, using PLA, 210 °C (clean from what I can tell) nozzle, 60 °C (clean, good condition) heat bed. My model is an STL from Thingiverse, and I sliced it with Prusa Control. Settings: 0.3 mm layers, 30 % infill, Support from build plate, brim on. I have run the printer calibration, z-axis calibration, etc. Only thing that might be a bit out is my z-axis might be a fraction too low. I have no issues when printing objects without support, and usually don't have issues printing objects with support (although typically these have a larger contact area of the object to the print bed as well)
After it prints the brim (which adheres well), it tries to print the support layers for the "actual" layers that will get printed first. These layers do not touch the outer brim. They go down with a little bit of "squeeze out" when the printer does a 180-degree turn. (this can be seen on the right hand end of first picture).
Then, it attempts to print the whole-of-base support structure (refer to pic 3 and 4 for details). Where these support layers touch the outer brim, they adhere well. When they touch the initial support layer sections, it tears them up, leaving a big mess.
What appears to me to be happening, is the small sections that get printed first (circled in red) are either not adhering well enough, or somehow getting "ruffled up", or are printed too close to the subsequent, broader strokes of the rest of the support layer, such that when the rest of the support layer is printed, it is tearing up the initial small sections. Having 2 densities of support layer per layer seems to be causing issues.
Failed print, still on the bed. At the right, there is a section of "fine" support material that sort of survived.

Close up of the failed first layer. The broad strokes seem to adhere well except for when they meet where the fine layer was - after that it's just a big mess.

Slicing in Prusa control (part 1): shows the different support structures and very minimal contact of actual object to the bed (orange)

Close up of other problem area in PC slicing. No actual contact of object to bed here. Also, as a side note, why the funny diagonal line cutting through the rest of the support structure here?

Looks more like your z-zero is too high, not too low, and thus the support structs are "unhappy" at short-run, sharp-turn points.

Looks like an adhesion problem. Also, 210 for PLA is pretty high, maybe it is too hot and does not cool fast enough so than is ripped from the bed while it is soft.

@0scar I am printing some spools of PLA at 230 on my printer as otherwise, layers are not adhering properly - so the temp is printer/material specific. Would rather play with bed leveling and temp in that particular case

Quick, low-tech solution:
There might be several issues in your question, but in relation to bed adhesion, I'll share one of the most useful tips I wish someone had told me when I started out: Spread some glue-stick over the area to be printed.
I used ordinary school/craft glue stick (which I stole from my daughter's school pencil case) - the kind for gluing paper. I use a purple one, so it's easy to see and easy to clean up. I apply a little glue then smear it around with a wet finger to make it a bit uniform.
I have a heated bed (FlashForge Creator Pro) and have used this little trick with a range of filaments. In almost every case, it helps adhesion enormously. Parts and supports stick like mad! But they still come off easily enough the usual way. It is a weak glue, so it won't lock the part to the bed. Once the part is off, the purple glue is visible when wet, so it is dead easy to clean up the part and the bed in a minute or two.
This trick is so easy that it is worth trying first for any adhesion issues, before digging deeper.

With a good bed surface (as I believe this printer has), this shouldn't be necessary - but you're right, it's a useful 'quick fix' whilst getting more familiar with the details.

@SeanHoulihane, In my early days with my Creator Pro the highly effective heated bed sometimes got ABS prints stuck so hard that I damaged the bed (gouged the aluminium below the surface coating) getting them off. The glue-stick helps to keep parts firmly in place while printing, but it also stops them from getting stuck on like concrete. It seems to be a Goldilocks Zone... not too weak, not too strong, but just right!

It is hard to determine the exact source of the problem as there are few possibilities (I am assuming that you have a single nozzle and only one filament in use):

One of the hardest issues for me to get on my printer was fact that my auto-level sensor was mounted about 0.5mm too high - so please check that as this will give you a bit higher Z than expected.
Printing speed matters  - for some prints I was slowing my printer to 20% of nominal speed to get adhesion
a hair-spray layer or a masking tape on the bed could help with getting the grip
also you could play with nozzle temperature de/increasing by 5 degrees and see how it is going

Increase the extrusion width for the first layer. This will ensure that more plastic is extruded and will help with adhesion tremendously. Check our this link for more information: https://www.simplify3d.com/support/print-quality-troubleshooting/#print-not-sticking-to-the-bed.
The prusa i3 mk2s provides an option to "live adjust" the Z height during a print. You can try raising/lowering your nozzle with this feature to see which way it will adhere better, and then reset the Z to that value once you are satisfied with the adhesion and quality.

I've seen this on my Prusa clone. It looks to me like the nozzle is a bit too close to the bed so not enough plastic is being extruded. I got a perfect PLA print at 215 °C and 0.2 mm for the first layer and 210 °C with 0.15 mm for the rest. When I tried 215 °C/0.3 mm first layer and 210 °C/0.2 mm on a large print I got poor adhesion and a warped corner. I used the same Z height offset.
I didn't get a picture but it looks like the opposite problem to yours; not enough squish down on the first layer. I print with hairspray directly on aluminum and usually get great results. I'm going to retry with a more negative offset and will post pictures of the results.


text:
Anet A8 - X and Y axis not square - how to fix?
I have an Anet A8 printer for about 4 months, set up pretty well (or so I thought) and printing a number of models pretty well. I made a large 3" x 6" box with a sliding lid yesterday and when it was done there was a gap on one side when the lid was slid on. I checked the parts and it turns out they are not square - which means the X and Y axes are not square to each other.
I'm wondering how to adjust this - I'm thinking that extending the distance between the back of the frame and the front by adjusting the threaded rods that separate them to a wider distance on the side where the angle is obtuse. Obviously one of the first things I'll check is that the distance between the front and back is the same (I can't imagine why I never checked that before, come to think of it).
Does this sound like a sound plan?

Please post a picture or two of the print.  It may be a matter of slack in the drive belt(s) rather than the physical mounts of the carriage.

Ended up being rushed last night and didn't have a ruler of sufficient length to check the whole printer. I was able to determine that the distance between the front wall and the intermediate wall was exactly the same. Ruler wasn't long enough to reach all the way back.

I managed to print a 20 mm cube, and it showed that there was a difference of about 0.6 mm from one diagonal corner to corner than the other. Also showed my X dimension was about .2 mm thicker than it ought to be. Y was withing 0.05 which seemed good to me. Z was spot on. So it looks to me as though it's definitely skewed from X to Y. I'll know more when I can get a longer ruler on it. Then I need to figure out how to correct it.

Pretty difficult to say on such a small cube. Print this: https://www.thingiverse.com/thing:2280529 and measure the diagonals. Have you replaced the belts already? This is probably your main problem!

Thanks for the thing. I'm in the process of adding new frame braces and X/Y belt tensioners, the work should be done tonight and this is the first thing I'll try.

To correct x-y axis alignment to 90 degrees:  Loosen the nuts on the two threaded rods at one end and in the middle. Lower the Z-axis to its lowest level. Place a square block of wood or metal so that it rests on the table and is snug against the X-axis rods.  Slide the table so that either its rear or front edge is under the edge of the block.  There you can clearly see any misalignment by comparing the edge of the block and the edge of the table. Now the 'fun' part: rack the entire assembly, pulling the diagonal corners to square the table and block.  You may have to tape the assembly down to keep it in place while you spin the threaded rod nuts back into place....gently,then carefully snug the nuts while watching the table and block to insure they stay put!

Actually this worked and is pretty much what I ended up doing in a roundabout way. I added a set of braces on the frame to stiffen the front and back, and when I was done I checked the ends against each other diagonally and slowly tightened up the frame until everything was right and square. Now when I print objects they are coming out square or nearly so.

Neat trick with the wood block, but I don't like forcing the frame. What I did was widening the holes for the threaded rods in the front plate (e.g. with a Dremel milling or sanding bit). This way, I can just loosen the front-most nuts, and then slide the front plate left or right, which causes the "guide rods" to move with it. This way, I can directly change the X/Y angle without requiring any force. Then just re-tighten the nuts carefully et voilà -- square!

I recently went to the same issue on my CoreXY printer (culprit was uneven belt tension in the 2 belts), but you have a Prusa style printer like my first Anet A8 printer.
If you just found out (because you are printing large models now) but always had this issue it could be frame related. You should check your printer and try to fix the geometry that is causing this. If this is impossible you could fix this by changing the firmware (see below). If large prints used to be accurate, but are now skewed, you could be facing stretched belts. Replacing them will fix the issue.
Skewness compensation in Marlin:
When X-Y are skew (or any other plane like X-Z or Y-Z) you can fix that through the firmware software in Marlin Firmware. Please go into the Configuration.h file and look at the instructions; please search for "Bed Skew Compensation".
Basically you are required to print a giant square and measure the diagonals, these should be the same, but apparently are not in your case.

No, an AnetA8 has belts to drive the bed and the extruder carriage.  Not sure what Prusa model you're thinking of

@Carl Witthoft I also have an Anet A8 which is a Prusa clone, I have no clue what you are asking here! The Y axis is not properly aligned to the X axis here, therefor he needs to check the frame. Or the belts.

Sorry -- your phrasing seemed to intimate the lack of belts.  It's pretty difficult to assemble a Prusa clone in a way that causes X-Y not to be perpendicular.

@Carl Witthoft No problem, the frame is acrylic, reasons enough to introduce non perpendicular movement when improperly fastened (allthough tough I admit). Even the original Prusa itself has X-Y compensation it the firmware. The lack of information of the OP does not state if this problem was present in the beginning. But most probably the OP's belts are stretched.


text:
Anet A6 - First time assembled, won't turn on
I recently bought an Anet A6 and decided to assemble it today. When I plugged in the power, I don't get any sign of life from the printer. No lights, no bleeps, no fans which are starting to blow.
I checked the motherboard and it receives power from the adapter (I live in Europe, the Netherlands, so the voltage is 220V) but nothing happens.
Can someone help me out?
I added some pictures of the wiring for references. Display cables are correctly set (J3 to J3 and LCD to LCD).

+1 for crimping forks on the wires! Finally someone that understands to do it properly the first time! :) By the way, the voltage in the Netherlands, as in the rest of Europe, is about 230V.

Welcome to 3d Printing!
as this is a first day of the printer there could be a list of items...
First thing first: disconnect all peripherals, so we can test mainboard.
Before connecting PSU we can connect mainboard via usb and see if it starts (I will probably use a power bank in that case to avoid burning USB (worse case scenario)).
Then you can use cura or another host program to connect to the printer and validate firmware. If the printer is not recognized we can reflash the firmware using provided app or ArduinoIDE .
If all looks good we can check PSU.

please check output voltage from power supply unit (shall be 12V) (on the terminals, there is a small voltage regulator on the lefthand side)
then double check polarity
connect power to mainboard
check if we have same voltage on mainboard terminals
then check if we have 12v on the fan terminal (40 * 10 fan shall run all the time on the hotend)

if that is done and we have power provided to the mainboard then we need to check for 5V that powers the arduino mega2560 (that could indicate a faulty power regulator)
Select one of the available sockets and measure voltage on VCC and GND pins. If we have 5V then we can connect pheriperials one by one, always switching off PSU and disconnecting USB.
If one of the underlying components is faulty then you will see straight after powering the mainboard.

image source

Thanks Prof, I did a recheck and saw that my black power cable went to the + side and the red to the -. I followed the youtube instruction from Dan, but I think I got those mixed up #rookieOfTheYear. Thanks anyways for the help!

authors: นายอุดม หงษาชุม


text:
Removing protopasta conductive PLA skirt from a bed
I have a simple printer bot metal with a heated bed, the heated bed I am not using. I am using conductive pla by protopasta
The conductive pla is not that strong, so when I take my pieces off the board, sometimes they break. The only time it appears to be invincibly strong is when it sticks to the bed plate! I cannot get the skirt off the bed plate, no matter what I try

a razor blade does not work, even when the bed isn’t heated and after dumping a bunch of acetone on the board
using no skirt does not work, as the printer clogs itself
it is difficult enough to remove to the point that printing itself isn’t fun
when scratching it off, the pieces only chip, because they stick better to the bed than they do to themselves (unlike PLA)

What’s a good way to remove a conductive pla skirt from one of the beds? The skirt is the initial outline a printer lays down, it is very thin

I have no experience with your printer model nor with protopasta conductive PLA but since your problem is "too much adhesion" I would simply suggest to follow in reverse all the usual advices on how to make the first layer adhere better (a far more common problem).  The list of suggestion could be:

Print fast
Do no squash the first layer (see @fred_dot_u answer)
Make sure the part fan is on
Reduce the temperature slightly
...

The problem could also be due to the chemical interaction between the surface of your plate and the specific material (for example: it is known that glass - a relatively difficult surface to use with PLA - bonds so well to PETG that sometimes it chips off the bed when you remove the print).  If this is the case you could for example cover your bed in painter's tape and see if the protopasta conductive PLA adhere worse to it than to the bare bed.  Worst case scenario, you could remove the tape with the print and scrub it off from it afterwards with a metal brush or a bit of sandpaper.

I ended up using painter's tape. I think it is a chemical interaction with the bed.

Based on your description "it is very thin" about the skirt, and by the other characteristics you've provided, I suggest that your z-height for the first layer is suspect of being too small, too close to the bed.
If you have calibration specific to z-height only, re-calibrate and make a test  print with skirt. If the test is better, this tells you that the previous setting was at fault. If the test is not better, use a different setting by 0.01 mm or 0.02 mm and run another test.

I think the setting having the most significant effect would be to increase the Z-height by 0.05-0.1mm so that the skirt is not "sandwiched" against the bed like typical first layers in FDM. This should reduce the adhesion enough for you to remove the skirt from the bed without damage.
Alternatively, you could also increase the skirt extrusion width if possible (more material=stronger) and/or print another layer of skirt on top (skirt layers=2).


text:
Platform support up to a certain Z height in Ultimaker Cura/G-code
Ultimaker Cura offers a platform support type of “touching buildplate” which enables the printer to only make a raft for parts of the object that should be touching the build plate. It also offers “everywhere” for any object that might be hanging over the build plate.
I have a need to only offer support for overhangs up to a certain z height, such any overhang located at a z-point of 4 mm or below. Is there a software that will enable this, either as a setting/addition to Ultimaker Cura or just a G-code export for Pronterface?

Why don't you care about overhangs higher up?  what "magic" allows those to print properly but not the lowest overhangs?  What's the real concern here?

Basically, I have an irregular structure where I need to arrange it in a certain way to limit post-print-finishing. The support structures cause some of the irregular structures to snap off when it’s removed from the print bed. I don’t think sanding or acetone baths are a good way to smooth ABS -perhaps that’s the real problem here, I need to hide support structure connections prior to post-finishing, and this irregular surface is the only spot to do that. These high-up overhangs have a very low angle of overhang and should connect fine without support

Is there a software that will enable this?

Yes, as of Ultimaker Cura 3.3 Beta, Ultimaker Cura allows you to specify an area which will not be considered for adding supports. In your case you could define everything above 4 mm to be excluded from building support structures.
You can look here for this very new feature, it might be what you're looking for.

Is there a software that will enable this?

I don't own a copy of it, but from talking with other 3D printing enthusiasts, I know simplify3d is the slicer out there with the most granular control over support structures.
I'm unaware if it has a setting for exactly what you want, but I know it has the possibility to manually add support in selected parts of your model, so - depending on size and complexity of your model, and on the level of accuracy you need - it may well be an option for you.
It is proprietary, commercial software with a "no question asked" refund policy.

As an alternative, look into  3D modelling tools which allow you to add your own support towers to the model itself.  Do that, then set your slicing tool to "no support" or equivalent.


text:
At which point does a delta 3d printer change the G-code in order to work in its non-cartesian design?
For example, to make a DIY cartesian 3d printer you could use/do the following:

Create G-code using a program of your choice.
Load it into Universal G-code Sender (GRBL).
Pass it into an Arduino with GRBL.
The arduino can pass the instructions to the drivers through a GRBL arduino uno shield.
The drivers will control the steppers.

If you want to make a DYI delta 3d printer, which point of this whole process needs to be altered in order for the delta printer to work properly? Is there an existing open source software for delta printers/cncs?
EDIT: This question could be asked about any kind of non-cartesian 3d printer, including Delta, SCARA, Polar, etc.

The short answer is that the handling of the non-cartesian design is done by the motion-control firmware running on the Arduino.
The long answer:
I don't believe GRBL supports non-cartesian designs, and it is not commonly used for printers. It is more often used for mills, routers, or laser machines. 3D printers will typically use a firmware such as Marlin, which supports several printer designs, including Delta machines.
At no point is the g-code itself changed. The motion control firmware running on the Arduino or other controller interprets the g-code and determines which way and when to step each motor to accomplish the motion.
With a simple cartesian machine, commands for the X-axis only relate to the X-axis motor, but for a non-cartesian machine the axis and motors have complex relationships. The firmware must be programmed and configured to control the motors correctly.
The g-code itself is never passed to the drivers. The commands to the driver are simple electrical signals to "enable" (to energize the motor power - even to just hold position), "direction" (which way to rotate the motor shaft), and "step" (which causes the motor to rotate by one step in the selected direction).

Every 3D printer or machine tool that is commanded through G-code must interpret the G-code in terms of the particular mechanism.  Even a Cartesian machine in which there is a clear X, Y, and Z axis, each with independent actuators, interprets the G-code and adjusts for the scale factors, considers the current kinetic energy and the implicit changes in the kinetic energy, and constructs a move plan to implement the G-code.  This involves considering the velocity limits, the acceleration, the jerk, and possible higher derivatives.  This plan is passed to the motor drivers, and the mechanism responds.
A delta mechanism is really the same.  The difference is that there is not a distinct X, Y, and Z axis, even though the commands in the G-code are given in Cartesian coordinates.
My second 3D printer is one I designed using standard hot ends and extruders.  I'm using the reprap firmware, and haven't adequately studied the kinematics.
My first milling machine, however, was a delta machine with 3 additional degrees of freedom -- a machine style generically called a parallel-kinematics inverted Stewart platform.  In my kinematics code, I plan a movement by breaking the Cartesian command into small enough segments that the non-linearity of the 6-axis movement space never exceeds the tiny error of the actuators.  I developed a CPU-intensive but effective calibration system that estimates the errors that I introduced when building it, and so the mechanical performance is good enough.  The machine itself is a 5'x6'x6' frame of welded steel, so it is pretty dimensionally stable.
A delta 3D printer is simpler because there is no control over the roll, pitch, and yaw of the hot end.  Unfortunately, not being able to control also means that you are subject to whatever errors are introduced in the construction.
"Bed-leveling" of a delta printer consists of estimating some of the machine-unique parameters and compensating for their effects: cup, bowl, ripple, and tilt.  Applying these adjustments is done in the kinematics code as a further modification of the G-code Cartesian parameters to the leg-space delta mechanism motions.
TL;DR
The G-code is not modified, but the parameters expressed in the G-code are adjusted and interpreted in light of the machine kinematics so that the intention of the G-code can be faithfully followed.


text:
Problem with print bed height on Creality Ender 4
I am a novice to 3D printing and have encountered an issue that I cannot seem to solve. Hopefully someone here can point me in the right direction.
I have a Creality Ender 4 that I purchased a few months ago and up until about 4 weeks ago, it worked great. I had moved it from its original place and in doing so, something became amiss in the firmware as it would no longer heat up the print bed either manually or by sending print commands via USB. The SD card slots would also give errors when trying to print from an SD card. So, after doing some research, I ended up flashing the firmware in hopes that it would reset any of the hiccups I was having.
This both did, and did not, work. I tried MK4Duo, but apparently there was no support for my auto bed leveler and the bed was coming up and hitting the nozzle tip when I tried to print. I switched and uploaded Marlin 1.1.8 which seems to have solved the non-functionality of the auto leveler, but it has caused a new problem that I just can't solve.
Now, when I try to initiate a print, the bed will not raise high enough. It stops, either when I set Z to home, or try to print, at about one quarter of one inch from the tip of the nozzle. Of course, at this point when the print starts, the extruded filament just comes out in mid-air like toothpaste and curls up all over the bed. I can manually push the bed higher to the point it needs to start at, but it still drops too low when I try to print.
I am comfortable enough in using Arduino to try to correct the problem in the firmware (if it is a firmware problem), but I'm just not sure where I need to look or what I need to adjust. If someone would be kind enough to assist me in tracking down some possible places to look, or what might be causing this, I would be extremely grateful! I want to be able to print again!

When homing, the z endstop must be reached. Does it reach the stop at the top? It is strange if the platform stops before the endstop on homing! Is this stop height adjustable, or does the stop touch a fine tuning screw (that has moved) on the platform? The thing is, you cannot close the gap when the endstop is limiting the platform movement.

do you have auto-leveling?

Interesting design!  I like the X-Y carriage setup, but I'm concerned that all the support for the bed is along one edge. that seems guaranteed to lead to sag towards the far edge, and no way to compensate. If they put a second Z-drive (and guide rod) on the far edge, I'd buy one

Thank you for the comments! Yes, I do have an auto leveler installed. It is functioning becasue when I manually push the bed higher the auto leveler will detect the bed when it gets close enough. If I leave it there though and go to the control panel and tell it to print from the SD card, the bed will drop back down to the previous position, about 1/4" below the nozzle tip. It won't raise back up to let the auto leveler detect it. The regular stepper for the Z movement isn't active since the auto leveler is plugged up in its place on the motherboard.

In moving the printer, either a wire was loosened/disconnected, or something shifted - Z-threads/screws turned, without the firmware/controller being aware, or the springs in the bed have changed level. Manually re-homing/re-calibrating should fix it. It's unlikely that in moving the printer the firmware changed. Does the new location the same "flatness" as the original? Was the original completely flat? Maybe the printer was calibrated for a slight tilt in the original location, and that tilt is no longer present. If you move the printer back to its previous location does the issue disappear?

I had the same problem, I noticed that the bed never tried to go up when the z-limit switch sensor was connected. If i disconnected it and attempted a Auto-home the bed will try to go up to meet the sensor. However  installing the auto leveler sensor fixed it. With that connected instead the process completes correctly.

@Greenonline This one has 5 tags... and might seriously benefit more from being tagged after the machine [tag:ender-4] than one of the others. Would you look after this?

@Trish - do you want to add the add the ender-4 tag? Oh, I see, one (or more) of the other tags needs to be deleted. Hmmm, which of the 5 tags, that it already has, is the least important? Thanks.

@Greenonline I do actually don't know! but I think that the question doen't touch the topic of the Z-probe or the Z-axis in itself, but only via bed-leveling

@Trish Good point. Although, on a second reading, the auto-bed leveler seems to refer to the z-probe

Moving a printer would most likely affect the hardware rather that the software. Unless you have tinkered with the software over USB or loaded an unknown G-code file over SD card that has embedded G-code commands that change your settings.
The most likely solution is that the printer or parts of the printer shifted as such that the printer is not aligned anymore as it used to be. Re-calibrating the machine should fix that for you.

also: checking wiring should be the first step anyway.

@Trish,yes that should always be the first step, is everything well connected, thanks for the addition!


text:
3D scanner data acquisition
I found an old Creaform3D EXAscan laying around at the company I work for, and tried to plug it on a computer to see if it still works.
I discovered that it uses a software called RapidForm for data acquisition, but its license is expired.
I looked in the manufacturer site for drivers or something similar but there isn't anything.
Is there any other software or way to read the data coming from such scanner?

The Creaform EXAscan is according to the manufacturer a laser based machine. This means that it determines data points and their positions by some triangonometry done with a laser, 32.000 times a second, resulting in very high density point clouds. This demands a powerful program to work with.
At some point, your company used Rapidform, which costs a wooping 10 to 30 grand for a license. Other software in this niece are - according to a solidworks thread - Geomagic and PolyWorks. The gist of the thread seems to be that these "big 3" were the best ones at the market in 2011. However I have no idea if they work together with the given hardware or what the later two cost.

So if the original manufacturer still exists, (which they appear to, and even list your scanner under 'legacy' products) your best chance of getting it working is going to be to contact them directly. Using proprietary hardware WITHOUT the associated proprietary software can range from merely tedious but possible, to outright impossible, depending on the specific company. Oftentimes with tech products like this, the business model isn't about the product itself, but about the license fees for the software to use it. That they can charge yearly for. It's possible that the raw data is just a stereo camera file with extensions renamed, and equally possible that the firmware in the scanner will do some sort of check for valid license before it will even start scanning, they don't really have much info on their legacy products on their page

it is a laser based machine, so data pickup is clearly different from a stereo photogrammetry with structured light.

yes but thats not really the point, the point is it could equally be a standard format or something proprietary

the programs are not made by the same maker as the software - they will use some kind of interface, but if this is an industry standard or a licensed knowledge I can't tell.


text:
Threads for nozzle (Anet A6 extruder)
How do I know what nozzle to get for my Anet A6 printer? I want to get some hardened nozzles because I would love to print with some glow in the dark filament, but I know that eats up brass nozzles fast. But there is so many thread differences so I don't know which one to get, or even what thread the Anet A6 is. Could I have some help finding the thread type and what hardened nozzles would be recommended?

The Anet A6 uses the mk8 extruder (also used by the Anet A8). Please search for mk8 nozzles (for 1.75 mm filament). These nozzles use M6 threads. Standard nozzle size is 0.4 mm.

look for MK8 or V6 nozzles that are for 1.75mm filament.
but to answer your question the exact threading is M6 x 1mm thread pitch
both MK8 and e3d v6 nozzles use m6 x 1mm pitch
Source: manual measurement of both my brass mk8 and stainless steel v6 nozzle


text:
Why is a heated bed important?
I hear that heated beds can help with removing finished prints, but not all printers have them!

Is this a nice to have or must have feature?
Are there any downsides to heated beds?

I'll try to give it a shot as the other answer (perfectly sound answer b.t.w.) does explain "how" we use heated beds, but not "why" they are actually needed for good prints.
Plastics or polymers are mostly amorphous (no macro crystalline structure) and usually relatively hard and brittle at low temperatures (this is referred to as "glassy"). By increasing the temperature of the plastics the state of the material changes as it becomes soft and more ductile (called the viscous or rubbery state). The temperature at which this transition takes place is called the "glass transition temperature". It is this temperature where you would heat your bed too (or close to this temperature). Below the glass temperature, the expansion is reduced/low because the polymer chains cannot move easily due to the closer packing and stronger inter-molecular forces; increasing the temperature increases the expansion lowering inter-molecular forces. The difference in stress between the bed and your print is therefore reduced (as of the expansion  of the heated polymer).
This explains why we use heated bed to get the prints to stick to the bed. To answer your question why it helps in removing prints is that when the temperature is lowered, the polymer gets back into its "glassy" state, shrinks a bit and automatically loosens the print from the bed.
Indeed for printing PLA you can print without a heated bed, but for materials with a higher glass transition temperature and higher printing temperature it's almost a must to have. Downsides of heated beds are that they require a lot of power and when improperly installed lead to burned wires and connectors. It's usually wise to strain relief the wires from the bed and use proper gauge silicone leads and connectors.

Overall a good answer, but this bit is inaccurate: "..as the internal stresses are lower because of the more viscous state of the material".  There is no intrinsic "lower internal stresses" associated to the viscous state.  The reason why the print sticks better is that there is not as much shrinkage from the moment the plastic is extruded as it would be with a cold bed.  Internal stresses within the print are not due to the "state" of the plastic either, but to the differential of expansion between layers, if that is what you were referring to. :)

@mac Indeed, not related to the state, I edited the answer.

It can help with bed adhesion. However, most 3D printing plastics will warp without a heated bed (since they shrink as they cool). ABS is notorious for this, although PLA is not so bad, and you can get away without a heated bed for small parts. ABS is so sensitive that you may need a heated (or at least draught-proof) enclosure, as well as a heated bed. If you are considering buying a 3D printer, it is best to get one with a heated bed, unless you are on a very restricted budget. If you buy a printer without a heated bed, you will soon realise that you need one.

There is no simple answer. I will only cover the three main filaments: PLA, ABS, and PETG.

ABS:

ABS likes to warp, and dislikes breezes and temperature changes. so a heat bed is required, as is some way to keep breezes off and heat in (I use a plastic tarp over my printer).
Although there are print surfaces that will claim to stop the warp. but a print surface can not change the nature of the filament.
A heated bed is pretty much required for ABS

PLA:

PLA is currently the most popular filament, it has low warping tendencies and it likes breezes, and prints really easy.
PLA does not need a heated bed, but if the part is big it may peel off the print surface.
A heated bed is optional but will help with any warping you may encounter.

PETG:

PETG is described as combining the printability of PLA and the strength of ABS.
PETG is quite stringy and has a higher slightly chance of warping then PLA.
A heated bed is recommended, and will help keep it from warping.

Now, for print removal, a heated bed can help as well:

Most PLA prints, especially smaller ones will remove just fine without a heated bed,
Medium prints having a removal tool will get those off
A heated bed is really helpful for removing large prints or prints that won't release using other methods.


text:
Arduino and Ramps powering up
I want to run two stepper motors using Arduino Mega 2560 and RAMPS 1.4. But, somehow I burned the Arduino while I was connecting the motor and plugging the board to the computer.
Can I plug external power supply and USB connection to the computer at the same time?
Additional info from comments
I am using RAMPS 1.4 with Polulo red stepper drivers and Arduino Mega R3. I am only using two Nema 17 stepper motors and not using any hotbed or anything else other than the two stepper motors for the x and y axes. I am feeding 11.9 V supply to the RAMPS board. When powered on, can I plug the USB to my computer?
Suppose I have connected two motors on the X and Y outputs of the RAMPS, and the external power supply is on, then can I connect my Arduino to my PC using USB? Will it burn my board or not?
My only trouble is that when the board is on load, connecting the USB to computer motors would take power by Arduino pins instead of the RAMPS external supply.

This question would be better suited for the electrical engineering or arduino sites on stackexchange, as there is really no specifics for it being a "3d printing question".

I think this is an electrical engineering question, but it seems to be an EE question within the context of constructing and troubleshooting a 3D printer.    As an EE, there is no specific problem with what you tried, provided that all supplies are properly isolated.  Before burning another Arduino, reconnect the parts you have now one at a time, check for unexpected voltages.  In particular, check that the ground levels are at zero or near-zero potential difference before connecting.  Also, be sure that all grounds are tied together.  The motor supply ground must be connected to logic ground.

  Grounding is a large subject, and someone will justifiably pile onto this answer with concerns about ground loops and noise, but if your grounds are not common, you risk sneak paths and destructive voltages when you interconnect systems.

From your comment about D1, and looking at the link provided by the Professor, it states D1 should only be installed if the 5A rail is powered by 12V. It can be omitted and the Arduino will be powered from USB. You will want D1 installed if you add components to print without a PC. To reiterate, D1 MUST be omitted if you are powering the 5A rail by more than 12V, or the power is not absolutely clean, otherwise you may damage your ramps.

I had a similar issue building my Prusa i3 Mk2s clone.  I was constantly hooking & unhooking my Arduino from my PC while the printer was plugged into the mains.  At some point it had enough & it released some "magic smoke".  Later on I found out this was the power regulator on the Arduino.
You shouldn't need to plug in the USB and the external power to the Arduino at the same time, but if you did, it is smart enough to only use one.
That being said, by default the RAMPS passes 12V straight to the Arduino in order to power it (the Vin pin).

now i fixed the problem.actually the diode d1 was creating that problem.

i removed the diode d1 now everything is working good.

@sandeepkumar - Hi Sandeep, could you post an answer stating that the problem was solved by fixing the diode D1?  To do so, please flag the question for re-opening or leave us a comment - that way we can re-open the question for you to be able to post the actual solution as an answer... It may help someone with the same problem. Many thanks. :-)

The answer is, yes you can, but you need to follow guidelines.
Reversing +/- or otherwise incorrectly connecting power can destroy your electronics and cause fire hazard.

From RepRap wiki - RAMPS 1.4

Maximum Input Voltage Power Supply without diode There are three
limiting factors to the maximum voltage that you can put into the
RAMPS:
The Arduino Mega maximum input voltage Filtering capacitor maximum
voltages PTC fuse maximum voltages First, the 1N4004 diode connects
the RAMPS input voltage to the Arduino Mega which has a recommended
maximum input voltage of 12 volts. If your board does not have this
diode soldered in (or if you cut it), you will need to power the Mega
through the USB connector or through a separate 5v line, but this
allows a higher RAMPS voltage.
Second, most boards use 25v or 35v aluminum electrolytic capactors
(C2, C3, C4, C6, C7, C9, and C10). To be safe, you should only go to
half of your rated maximum voltage -- thus if your board has 35v
capacitors (code VZA) then you should use a maximum input of 17.5v.
The absolute maximum voltage is determined by the pololu servo
drivers, which themselves are limited to 35V.
Third, the MF-R500 (5A) PTC fuse is rated to 30V and the MF-R1100
(11A) PTC fuse is rated to 16V. They will need to be replaced with
real fuses.
Power Supply with diode If your board has a 1N4004 diode soldered in,
do not apply more than 12 V to it. Original flavor Arduino Mega are
rated to 12 V input. While Arduino Mega 2560 can take 20 V, it is not
recommended.

i am using ramps 1.4 with polulo red stepper driver and arduino mega r3.i am using 2 nema 17 stepper motor only and not using any hotbed or somthig but stepper motors for x and y axis.i am feeding 11.9 volt supply to ramps.when powered on,can i plug the usb to computer?

yes you can connect usb from arduino to pc.

@sandeepkumar If you want to connect motors or switch wiring while the arduino is on and powered with any external DC source you can damage your arduino and also pololu drivers.

@FernandoBaltazar very good hint!

suppose i have connected 2 motors on ramps x and y,and external power supply is on,then can i connect my arduino to pc using usb,will it burn my board or not?

my only trouble is that when the board is on load,connecting usb to computer motors would take power by arduino pins instead od ramps external supply.

+1 - as this mentions diode D1, which was, apparently, the OP's issue.


text:
Mains powered heatbed safety
I'm building a 40x40x40cm corexy and I am quite impatient so I want the heated to reach the target temperature as fast as possible, so I ordered a Keenovo silicone heater
It is a 220VAC 1200Watt bed, so I really want to make sure that it is safe to use.
I also bought a Crydom D2450 SSR.
Could someone tell me if the wiring in the diagram I made below is safe?
Do I need to put a fuse or some other kind of safety?

The time to heat the bed is inconsequential compared with the time to execute the print.  Rethink your priorities.  For example, small changes in the infill percentage can have huge changes in print time.

@franc-navarro-cifani your conection is correct and your new heater will work like a clothing iron, will heat extra fast. normally the heat bed heats with in 5 minutes with one grid (12v) and with in 2 minutes. using both grids (24v).

@CarlWitthoft you are right, however, it is a long time if you consider that I like to seat by the printer and watch the first layer to make sure everything is fine before I leave, so it reduces considerably the amount of time that I spend at the beginning of each print

heads up: one thing to watch out for: crydom and fotek SSRs are extensively copied and sold by unscrupulous Chinese manufacturers and sold on ebay and amazon for much less than the ~$15 retail each should cost. If you have a clone, it's NOT going to follow the official specs in terms of heat, capacity, and insulation.

The most important thing is the following: make sure that any exposed metal surfaces of your printer are properly grounded. This includes the frame if it is made of metal, or the aluminium plate you might use as your heated bed. In the event of a fault, having the metal surfaces grounded protects you from getting shocked when you touch the printer. If any surfaces are aluminium, be aware that the oxide layer that forms on aluminium does not conduct very well, so make sure that you get a good connection.
You should consider adding a thermal fuse or bimetallic switch to the heated bed so power gets cut in case the bed overheats (to protect against the relay failing closed or firmware errors).
In principle, if the wires used are thick enough (capable of carrying at least 16A), then there is no need for a fuse. Assuming you are in a normal European household, then the mains line will already have a 16A fuse. If your printer connects to the mains using a IEC C13 connector (kettle lead, very common) then you should have a fuse rated (at most) 10A somewhere because this is the maximum rating of the connector. For a very small amount of added safety, you could use a lower-rated fuse instead (for instance 7A) but this is not required. Your heated bed can draw up to around 5A so you can't use a fuse lower than (or equal to) that. If you are indeed using an IEC socket to connect your printer to the mains, then it might have a fuse holder (or try to find a socket that does).
Your image suggests two possible fuse positions. It would be advisable to place the fuse near the live/hot connection, but as European power sockets are non-polarized, this is essentially a moot point.

The diagram you show is in compliance with the manufacturers' specifications so far as connections go.  Make sure any wire you supply is rated for the voltage and current intended for use.
If there is not a safety cover (typically clear plastic) over the junctions where you'll be attaching wires, you should add a cover, or alternatively put the entire relay inside a UL-rated box with stress-release feedthrus for all the wires.
It never hurts to add a fuse or breaker in the source hot feed.  I'd recommend slow-blow.  NEVER fuse the return side, since a fault or blown fuse here will leave everything live and floating
That said, this is more of an electronics question than a 3D printer question, so you might want to wander over to electronics.stackexchange for information on general design safety for high-current systems like this.

thank you for your tips, I will definitely cover the SSR.
As for the fuse, is there really a return side in AC?

In AC, one side (neutral) is usually referenced to earth while the other is hot/live/line. It is preferable to have the fuse on the live wire so that power is completely cut off if there is a fault. Otherwise, if the fuse blows, parts of the printer might still be live and give you a shock if you touch them. Unfortunately European power sockets are symmetric so you have no way of knowing which is which.

@Tom although symmetrical, it is easy to find out with a "Mains Circuit Tester Screw Driver" and plug it in correctly.

@0scar If you're building a printer (or anything else), then its safety shouldn't depend on the way the user plugs it in (you can't guarantee that nobody else will ever use the printer). In my opinion, it's not worth worrying about fuse placement (on live/neutral) because the printer should be safe to use regardless of how it is plugged in. I tend to just follow the convention for live/neutral on the C13 connector and place the fuse accordingly, but at the same time I'm aware that it's not going to give me any extra safety.

@Tom, true, but you can find out how to plug it in, and to be realistic, (who else is using the printer at home (for the majority of users, they are the only ones who plug them in). But I agree, it should not depend how you plug it in and that you should always be aware that it does not add more safety. I just pointed out that it is possible.