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Does having more curvier corners help warping more then smaller curves
I was experimenting with building an enclosure using fusion 360.
I was wondering if a part with rounded corners of a larger radius would warp less than smaller ones?
Also, any recommendation on reading material would be appreciated!

The context of this question is hard to guess. Please add more information to help us estimate what you might need as an answer.

In short, yes, it helps a little. Curves provide less surface area per unit volume (a sphere has the least possible surface area relative to the volume of the solid), and that reduces the rate at which the material in that corner will cool relative to elsewhere in the print, and also changes how the material can deform if and when it does cool unevenly. Uneven cooling of fine features, including sharp corners, is what causes warpage, as these areas typically cool faster than others. The curve also helps with bed adhesion, as the more rounded corner is more easily kept down on the bed by the various forces within the object and in the bed adhesion. Sharper corners depend more on the surface area under the corner itself to keep the piece properly stuck to the bed.
However, it's not a panacea. It's not always possible, for one; it's usually an option when CADing a "green field" design for a household item or other standalone product, but if you're making a replacement part for an existing device, or printing a figurine or other detailed model, you usually have to take the curves (and edges) that design gives you. Also, if you radius an outer edge of a hollow shape, but don't radius the inner corner to keep the material thickness constant, you'll end up with similar cooling problems as the apex of that edge cools fastest.
Strategies for avoiding warping are along a couple common lines, but exactly how you implement that strategy depends on the material and on the printer. One overarching strategy is to increase print surface adhesion; the stronger the part sticks to the bed everywhere on its first layer, the harder it will be for corners to lift. Exact techniques depend on the print material, but many of them, like blue painter's tape, Elmer's glue and hairspray, work well for several filament types. Adjusting the printed shape, to print a brim around the shape's base or even a raft under the entire object, are also common anti-warping strategies. The tradeoff is that the stronger the bed adhesion, the harder the part will be to remove from the build surface when complete, which depending on your print bed construction can cause more problems than the warping.
Blue tape is nice because it's cheap to buy and easy to apply to the bed surface, both of which mean you don't have to worry too much about damaging the tape as you remove the part, just strip the tape and put down another layer. But, it doesn't work for all filament materials; the only thing I've found that really works well for ABS, for instance, is kapton tape, which is significantly more expensive and takes a lot of effort to lay down a wrinkle-free, bubble-free layer over the entire print bed for a large part (especially on my MakerBot, which doesn't have a removable build surface on it, so I'm laying this tape down in cramped quarters within the printer enclosure). A glass surface painted with ABS slurry is an option I've not yet had opportunity to try for ABS printing, but plenty of people swear by it.
Cooling, especially uneven cooling rates, are another major contributor, but again, exactly how you deal with cooling depends on the material. Most plastics, especially PLA, tend to work best when you keep things as cool as possible; the coolest extruder temp that reliably feeds fil, the coolest bed temp that reliably sticks, part cooling fan turned up, and even a standing or box fan blowing through the entire work area to put as much air over the part as possible. What this does is to get the PLA down onto the print surface as a hot "putty", then immediately "freeze" that bead of plastic as a solid as the heat's removed, so the bead can't shrink as it cools more gradually.
Now, with ABS, this cooling strategy doesn't work, and in fact it's the worst thing you can do to an ABS print. The material is much more elastic than PLA, which is quite brittle, and has no true melting temperature, with a very hot glass transition temp. So, as it's laid down, the extruded beads quickly put the part under elastic tension as it cools. Shrinkage is a fact of life with ABS; the only thing you can do is to control the shrinkage by controlling the part cooling, so the part cools and shrinks evenly. ABS calls for a hot print bed for good adhesion, which will keep the first few layers warmer longer, but higher layers of the print will be further from that heat source, so if there's air moving over or within the work volume, these higher layers will cool more rapidly, at which point it really doesn't matter how good your surface adhesion is (I've seen prints split halfway up the model to relieve the tension by warping). So for ABS, a heat enclosure is pretty much a must. My MakerBot is built that way (in fact it's designed for ABS printing and works better with ABS than with PLA, which is supposed to be the more user-friendly material of the two), but most of your open-gantry RepRap-type designs will need something built around it, usually with a separate heating element to heat the work volume more than the bed is capable of doing.


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Lines appearing during ironing
I'm new to 3D printing, but have been having relative success with the Ender 5 Pro and Cura.
I'm making some coasters and using the ironing feature to smooth out the top layer. This is mostly working great, but there are lines left on the surface, consistent between identical prints. They appear to be seams between different ironed areas. They form when one continuously ironed area finishes, the nozzle leaves that area, then an adjacent area is ironed later, forming a seam between them.
I'm using the default ironing settings, on only the top layer. I have no clue what settings might be causing this, or if this is an avoidable issue.
Any ideas from more experienced printers?

what settings do you use for ironing?

All default cura settings. Zig-zag pattern, 0.1mm spacing.

Ironing isn't default, that's why I ask. PLA and what temperature, nozzle diameter, extrusion width?

Did you get this fixed OP? I'm in the same exact position was curious if the settings the other person referenced were a possible solution.

There's a couple of Cura settings that can help, that I know of:

In the 'Travel' section, change "Combing Mode" to "not in skin". Combing means it tries to move the head over areas that have already been printed. This is a good thing most of the time, but if it does it while it's ironing, it will make an annoying line. (I am not sure why this isn't automatically turned off for the ironing pass, but it seems it isn't.)
After enabling ironing, an option "Ironing Pattern" appears. Try changing this to "concentric." This produces a different pattern, which you may or may not like, but it seems less susceptible to those kinds of lines appearing.

Here are some other settings that might help. I'm suggesting these on the assumption that some of the lines are caused by the print head travelling over the ironed surface, which is what it looks like to me from your photo. I got them from this Cura documentation page, but it doesn't mention ironing, so I can't be completely sure whether they will affect the ironing step.

"Avoid printed parts when travelling" - this might help a bit more than just turning off combing, since it will try to go around the printed areas instead of just cutting across them. Apparently you have to enable combing for this to work.
"Z hop when retracted" and "Z hop only over printed parts." This should make it lift the print head up when it can't avoid crossing the printed part. It may be that you have to enable retraction, combing, and/or "Avoid printed parts when travelling" for these to appear.

I did try the combing setting earlier, and it didn't seem to change the effect. I'll try concentric on the next print.

I added some additional options that might help. (But I haven't tried them myself.)

The main assumption of this answer, that the lines are caused by the head traveling over printed portions, only addresses part of the problem. The raised portions are seams that happen when the head irons from one position in the middle of a face, then needs to return and iron the rest of it. The seam happens where the ironed portions meet.

@SteveHanov both of those things happen of course. I could be wrong, but at the time it seemed to me like the most visible lines in the photo are due to the head moving, because they cut diagonally across the "grain" of the ironed surface. There are some horizontal lines also, which I guess are 'seams' of the kind you mention. You're quite right that nothing I say here will get rid of those. (Although in my opinion the 'concentric' ironing pattern makes them aesthetically less displeasing, since they become part of the pattern.)

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Tuning time estimates in Cura
Cura consistently under-estimates my print times. I know I'm not alone here, but I've also noticed it seems most of the difference comes from travel and retraction times... that is, if I re-slice an object to minimize those operations the accuracy of the estimate improves. Also, the estimates seem more accurate for objects which require less travel and retraction than those which require more.
Is there a way in Cura to adjust how it counts time for those operations, and thereby improve the accuracy of my time estimates?

I think this question is somewhat related to Estimating printing time from Cura and is answered by Tim Kuipers.

@0scar: In Cura if acceleration and jerk are disabled (leave machine defaults alone), what values are used for estimating? The machine limits? Or the set values of the disabled options?

@R..GitHubSTOPHELPINGICE maybe it is better to comment on the answer of Tim Kuipers, he is or has been involved in Cura development.

@0scar: Done. Thanks for suggesting that. I'm having lots of trouble with bad estimates and I'd like to figure this out too.

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


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My 3D printer hotend always jams
I've just built my first 3D printer. It uses a Bowden setup.
When I try to print the extruder starts fine, but after a few seconds the extruder motor start skipping and the nozzle is jammed.
I tried a cold pull, but it didn't help. I removed the PTFE tube and tried to push the filament with my hand, it works but at the start I need the push harder but after it flows fine. But if I reinstall the Bowden setup, it works fine for a few minutes, but after a few seconds it starts again.

Note I am using silver PLA at 200-205 °C. I tried to raise the temperature to 215 °C, but it also jammed, and the filament what after I pushed out was black (it is a new hotend and I never used black filament before), like it was burned (if it is possible).

Welcome to 3dPrinting.SE! What temperature are you using at your extruder? What filament type (ie: PLA)?

Extruder clogging is, at its root, a matter of too much backpressure at the hotend. There are a number of more specific causes, but it very simply comes down to the fact that the printer cannot feed the filament through the hotend as fast as the extruder is pushing it in.
Things to check, pretty much in the order they should be checked/performed for a brand-new printer:

Extruder stepper calibration. With new printers based on RepRap firmware (Enders, Prusas, pretty much any printer in the \$200-\$400 range these days), one of the first things you have to do after assembly is to calibrate your E-stepper (the motor that drives filament through the extruder). The printer is given commands based on millimeters of movement, including the feeding of filament, and it has to translate those into finite steps of the motors. If those steps don't actually move the extruder or the filament as much as expected, the printer will behave poorly, including clogging. E-stepper calibration is pretty easy, especially on Bowden extruders; you basically disconnect the Bowden tube at either end, load filament through the stepper, cut it off flush with the end of the tube or the coupling, then tell the printer to extrude 100 mm of filament. Cut it off flush again and measure, and if it's not 100 mm, look for a command beginning with M92 in your printer configuration (it can be in the settings of your actual printer or a configuration script in your slicer software that gets tacked on to the front of the G-code files generated for use with that printer), and adjust the value you see after the E in that command by multiplying it by 100, then dividing by the millimeters of filament actually extruded in the test. Rinse and repeat until the printer is feeding the amount of fil you tell it to.
Bed height/leveling. This may not sound like it has anything to do with extruder clogs, but in truth, if your extruder is too close to the print bed at any point during the first layer, it can very easily clog the extruder by not allowing enough material to flow out the nozzle to keep up with what's being fed in. Bed leveling is a key step in print prep, and every printer behaves best with subtle changes to the bed leveling procedure. My guess is that you need to re-level for a slightly higher "zero-Z" above the build plate. If you're using the sheet-of-paper method, either use a thicker piece of paper, or go for less friction as you pass the paper between the nozzle and build plate.
Nozzle diameter settings. The standard nozzle tip diameter is 0.4 mm, however there are others. Your slicer probably expects the standard diameter as a default, so if you're running a 0.3, 0.2 or 0.1 mm nozzle for finer detail, the slicer has to be told that so it can adjust the filament feed rate. Otherwise it'll be jamming up to 16 times as much filament into that hotend as it should be. This isn't likely to be your problem but it's something to check; most extruder nozzles these days have the tip diameter engraved or pressed into the side of the nozzle, and if yours is unlabeled, try heading to the local music store and buying a single 0.013" guitar string (typically sold as a high E for acoustics). If that wire end easily fits through the extruder nozzle, you have a 0.4 mm, if it does not, it's something smaller.
Extruder clog/obstruction. That guitar string I mentioned makes a really good extruder cleaner. Just feed it through the extruder tip and gently push it up through the hotend till it pops out the top of the extruder, then feed it back and forth a bit to "floss" the extruder tip, cleaning out any minor carbon buildup. If you can't feed the wire completely through the extruder body from either direction, that's probably your problem, and fixes range anywhere from a little more pressure with the wire, to a narrow drill bit carving out the obstruction, up to removing the entire heat block from the printer, putting it on or in something that won't burn, and blasting it with a soldering torch to burn out the obstruction, followed (after letting it cool) by a bath in some acetone to dissolve any remaining gunk.
Gunked-up extruder hobb. The toothed wheel attached to the extruder stepper is called the "hobb" (you may hear it called a gear, but it's really not one as it doesn't mesh with another gear). As the printer feeds filament, especially if you've had jamming problems, the hobb's teeth will fill with shavings from the filament it feeds through. This can cause the hobb to slip against the filament, which not only reduces the pressure of the filament being pushed through the extruder, it accelerates the accumulation of gunk on the hobb. A short blast of canned air is usually all you need to clean the hobb; if it still looks pretty caked up, a toothbrush will sort it out. While you're at it, check the idler to be sure it's still spinning freely.
Filament type/brand/age. You mentioned it's "silver PLA"; the silver stuff I have is actually a "silk PLA" product, that sheathes the PLA in a jacket of another plastic (often PET) for that high-gloss appearance. These kinds of filaments can be very temperamental, as can filaments with glitter or fiber aggregate in them (also common in metallic fil colors). You have to have the printer settings dialed in just right, and some of these products just don't work well at all in some printers. Try getting some very basic, brand-name PLA filament like Hatchbox, ColorFabb, MatterHackers, MakerBot, etc, in a good primary color (avoid black or white; the color saturation affects how easily the stuff extrudes at a given temp), no silk finish or other modification. If that prints well, the suspect becomes the silver fil.
Extruder temperature. You're printing at 200-205 °C, which is usually good, but if you're getting problems, the first thing to do with PLA is to try printing cooler, not hotter. Case in point, getting PLA too hot can cause it to fully melt and drizzle out (vacating the extruder and causing it to overheat the fil further up, jamming the melt tube), it can gum up (directly clogging the extruder nozzle), and it can carbonize (as you see it doing at 215). If you're already flirting with burning your PLA at 10 degrees hotter, you are probably running too hot. Try backing off to 195 or 190 and see if that helps any.

Very complete answer! Welcome to 3DPrinting.SE!

I set it all, but it did the same thing.
When it starts the print with the outer edge (brim) it prints with fast speed it works fine but, when it starts the actual object -20mm calibration cube- it prints slowly and nearly instantly the nozzle jammed, and the extruder can't feed the filament and start skipping.

@VLKI - It sounds like you are either using a variable print speed setting, or you have widely varying speed settings between line types. What these settings are called and how you can set them depend on the slicer software, but long story short you'll want to keep the extruder moving at as constant a speed as you can.

I had a very similar problem with my printer, and it turned out that the bowden tube was not fully inserted into the hotend. The hotend is bored out to a very close fit to the tube. I had inserted it about a half inch, until it stopped, but it had only gone in to the top of the hotend.
After I inserted the bowden tube fully, my clogging issue stopped.
You can insert a toothpick or something and measure the depth, then mark the tube at the same measurement to ensure it gets fully inserted.

It is useful to diagnose your problem if you provide more information, specifically what material you are using and what temperature you are using on your hot end.
Even without the above information, it is likely that the hot end temperature is too low. At a low setting, the filament in the nozzle will soften, perhaps even melt as deeply as needed to be extruded, but as new filament is provided by the extruder motor, it also cools the heater block.
By increasing the temperature, you're ensuring there is sufficient thermal energy to handle the incoming cold material.
It would be useful to increase your nozzle temperature by 5°C for each test. Despite matching your controller's temperature to the manufacturer's specification, you can not be certain that the temperature at the nozzle and heat block are what you have programmed.

I use silver PLA with 200-205 C. I tried to raise the temperature to 215 C, but it also jammed, and the filament what after I pushed out was black( it is a new hotend and I never use black filament before), like it was burned (if it is possible).


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Very low strength of HIPS prints - Why?
I'm using a Prusa i3 MK3S printer. After ~8 months of printing PLA, PET-G, ABS I decided to buy some HIPS and print something with it. I cannot print >1 filaments at once, so I'm not using it as a support for ABS, I want to create some high durability working models, like gears, robot parts etc.
While the quality of my models is perfect, unfortunately their strength is disappointingly low. They easily undergo plastic deformation or break. I've tried lots of settings, some yielding better or worse results, but the problem is present regardless.
My settings:

Printer: Prusa i3 MK3S
Nozzle: Default 0.4 mm nozzle for Prusa
Layer Height: 0.2-0.3 mm
Temperature: 230-240 °C nozzle, 100-110 °C bed
Slicer: PrusaSlicer 2.0.0

I've read lots of tutorials regarding HIPS printing and they did not give me the answer to my question...
Am I doing something wrong or is it normal for High Impact PolyStyrene? At this point, the High Impact Polystyrene seems less High Impact than generic PLA.

It might. If HIPS is a single material with consistent properties, it might have a narrower temperature range.  Online references suggest up to 240 °C. Try that, then 245 and 250 °C. Maybe higher.

You might try upgrading your PrusaSlicer to 2.1.1. I don't know if the "Prusa HIPS" setting got updated since your 2.0.0 but it's worth checking.
For comparison, PrusaSlicer 2.1.1 uses these settings for HIPS:
Filament:

First layer temp: 220
Other layer temp: 220
Bed temp, first layer: 100
Bed temp, other layers: 110

Cooling:

Fan speed: min 20%, max 20%
Bridges fan speed: 50%
Disable fan for first 3 layers
Enable fan if layer print time is below 10 sec
Other cooling settings same as for PLA

Advanced:

Max volumetric speed: 11

There's also custom G-code for HIPS setting M900 K10.
I, too, want to print actual parts with HIPS. For me, it's because HIPS the lowest density of all the commonly-available stiff-plastic filaments, which is great for printing lightweight model aircraft parts where every gram matters.

If you are scraping for weight, consider foaming PLA! :-)

That foaming PLA is interesting... but really expensive. I'm amazed that it seems possible to make precision parts from a foaming filament.

The primary use of HIPS in 3D printing is to create sacrificial supports, which you're aware of. The material dissolves in lemon oil, making it popular for printing dense supports within complex shapes that can then be easily removed just by spraying the part down with Orange Clean.
I would not expect HIPS material sold for 3D printing use to have much if any strength, especially for moving parts. Outside 3D printing, most uses of the material are in expanded foam products like bike helmets, flotation products etc, and these applications require pressure-molding, which creates a higher-density object and hardens the foam's outer layer to make it tough enough for everyday use. Just extruding the stuff out into the open air gives you the same density (and strength) as a packing peanut.
If you want a styrene-type material that's strong, tough and relatively light, I'd stick with ABS. If you're looking for a challenge in a similar material, try nylon; it creates a lower-friction surface, is very tough but pliable, and its hygroscopy requires very careful handling of the filament (in some more humid climates, you have to feed it from a dry box through PTFE tubing straight into the printer; even the time out in the air between the box and the extruder is enough to get hydrolysis-related issues).
If you really want to print HIPS foam gears, the only thing I can suggest you try is an epoxy coating to give the object a harder shell while retaining the light weight. My wife does custom-applique vacuum tumblers (but who doesn't nowadays; my wife's making more money selling other people the supplies and equipment to do it), and her favorite stuff to use is Faux Rizzle; very durable, odorless, easy to mix and apply, and relatively inexpensive (many other art resins sell for about double what you can get FR for). Good luck to you.

Are you suggesting that HIPS filament goes to a foam when 3D printed?  Probably the weakness is because of bad bonding.  Might drying the filament and printing with a higher temperature be helpful?

Don't forget POM (acetal/Delrin). Although I hear adhesion is hell.

@cmm My first prints using this filament were even weaker, which was caused by bad bonding. The nozzle temperature was too low (220C). The strength improved after increasing the temperature to 235C. I don't know if increasing it even more will help.

@R..GitHubSTOPHELPINGICE Yes getting it to stick is not very easy, but possible, see "POM filament not sticking to the build plate?". Once mastered sticking it is great material for custom bearings.

@KeithS technically hydrolysis happens in the hot end at high temperature when humidity is present in the nylon (or PETG, maybe even in other plastics but I'm not sure). The hydrolysis is not reversible and degrades the material properties, while absorption of humidity before the hot end is completely reversible.

@FarO I'm aware; edited to clarify that the absorption of moisture in itself is not hydrolysis. It remains that nylon is very hygroscopic and it's hard to dry back out, so a totally enclosed feeding system is recommended.

I've been using HIPS for nearly 2 years now to print the housings of EDF units for RC planes. They come out light and strong but have poor layer adhesion, especially on thin-wall parts.
Normally I print at with a 260 °C nozzle and 100 °C bed but will try higher temperature when I upgrade my Ender 5 to a 32-bit board. Thin cyanoacrylate painted on the surface solves most issues. Sometimes I use a solution of ASA dissolved in acetone to paint the surface and bind layers together.
The EDF rotors I print from Apollo X which is a modified ASA that is easy to print but not soluble in acetone.

authors: Павел Моргачев


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Drift and stuttering on prints
I stopped using my Monoprice Maker Ultimate (re-branded Wanahao Duplicator 6) for a couple of weeks and am getting a seemingly random drift with all my prints now when re-attempting printing.
I also noticed a weird stutter when the extruder moves. It is particularly bad in one specific direction on the X-axis but is noticeable for all movement in the XY plane.
I have read online that this could be caused by voltage issues.
I have also read that it could be caused by over-tightened XY bearings but, given that it is happening in all directions, I am leaning more towards voltage issues.
Not sure if the drift and stuttering are related (I'd imagine they must be, but have no way of confirming). Would anyone be able to help provide troubleshooting steps for this as I am still very new to 3d printing?
I have provided a photo of what the drift looks like for this test model. I can provide more information if necessary. Thank you

With the power off, can you feel "catching" while moving the extruder along the travel range?

Hi, thanks for responding and apologies for my delay. I'm feeling some resistance in the X in one particular direction. Not so much along the Y axis. I wouldn't really call it catching though, just resistance. I've applied a couple drops of sewing machine oil to each of the rods and let the extruder run over them to try and spread across but that didn't seem to have much of an impact. Thank you again for your response.

I shook off my laziness and disassembled the mounts holding the stepper motors and tightened the belts. After doing so the drift was resolved.


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Ender 3 with BLTouch prints slanted lines
I'm having a problem getting a clean first layer on an Ender 3 with BLTouch auto bed leveling. Thickness seems to fluctuate all over the bed, but in a consistent (repeatable) way. Here's my attempt to print a single layer 5 square bed calibration test:

I stopped the print midway through filling the first square, but you get the idea. Lines go from too low so no filament comes out to too high.
I printed this several (many) times with slight settings tweaks and it looks pretty much the same every time; the ups and downs aren't random. For example, the center square always is always too low on the left and too high on the right:

The printer is a SainSmart Ender 3 Pro with a BLTouch V3.1 and Creality glass bed, otherwise stock. I flashed a bootloader and Marlin 2.0 using the instructions and pre-compiled firmware from 3D Printing Canada. I'm using the glass bed upside-down on the plain glass side (no coating).
I pre-heated and leveled the four corners manually using the paper method. I auto-homed and then lowered the hot end until it would just catch a piece of paper and used that height to set the Z offset using M851 and saved it with M500. It's currently set at -2.80.
I added G29 to GCode start in Cura, and it does a 3x3 probe before the print starts. Here's the output when I run M420 V:
Bilinear Leveling Grid:
      0      1      2
 0 -0.207 +0.172 +0.162
 1 -0.100 -0.160 +0.220
 2 -0.118 +0.215 +0.295

Here's what it looks like in the Bed Visualizer plug-in in Octoprint:

If I understand this right (dubious) it's showing that the glass is lower toward the front and left, highest at back-right. But it's only 0.4mm from the lowest to highest points. And the whole point of mesh leveling is to compensate for this anyway.
At Paulster's suggestion I turned off mesh leveling using M420 S0, leveled manually, and printed again. The result is pretty similar (note that this time I let it run all the way through):

Where should I start looking to diagnose this problem?
Update
I noticed my X-axis belt was a bit loose, so I tightened it up. It seems to have helped with the odd Z slanting. My test print is still not great though, so this may not be the whole problem. Also I've never seen this effect listed as one caused by loose belts, so it's dubious as the cause. Here's the current test print after tightening the belt:

It's flatter, but I'm still getting (I think) under-extrusion and some odd wobbles at the corners.

Did you try just leveling manually then running it to see what it would do without the z-offset?

@Pᴀᴜʟsᴛᴇʀ2 I did as you suggested and got a pretty similar result (added to question). Not sure what to make of this. I guess this means it's not an autoleveling issue? So where should I start?

The Ender uses a single stepper for the Z height positioning, this is not optimal and many times the cause for misalignment between the X-min and X-max side. Maybe you need to inspect the XZ carriage on the non driven Z side? Regarding your update, I doubt this is under extrusion, it looks as if the gap is just bigger on the X-max side. As this is a single Z stepper driven carriage, a higher X belt tension may indeed stress the XZ assembly such that it prints better.

@0scar Thank you for your help. What should I be looking for when inspecting the XZ carriage? This was a new-in-box unit that I assembled, and I think everything looked right and I did it correctly, but I lack expertise to be sure.

Basically you're looking for play in the system; e.g. loose nuts or misalignments. You can also do some measurements of the four corners with respect to the carriage at different heights. I would also look if the bed is stable, not wobbling/tilting, to be sure.

@Robert: Make sure both of the mounting plates (the one with the extruder and the one at the other side) are bolted perfectly level with the gantry (horizontal aluminum extrusion bar). Because of the way they mount, there is significant play, when they're not tightened down, and if you tighten them down misaligned you'll have all sorts of trouble. If this weren't a new unit I would also suspect uneven wear on the wheels; it's possible that one or more of the wheels is just defective and not centered correctly.

This turned out to be a problem with the tightness of the rollers at the left and right sides of the X-axis gantry (that roll up and down the Z rails).
Z-axis motion is driven by a single stepper motor on the left side, so the rollers have to be just the right amount of tight to keep the right side in sync. If the right side is tighter or looser than the left then it lags behind, which gives the gantry a slight slant which changes as it goes up and down.
If the gantry is changing pitch throughout the print, no amount of bed leveling will help. Even auto-leveling is worthless, because the readings the BLTouch takes become immediately out of sync with the gantry as soon as it moves again.
The solution is to adjust the eccentric nuts in the rollers on the left and right. The best description I could find is that they need to be just tight enough that there's some resistance if you roll the top wheel with your finger, but loose enough that you can roll it without forcing the gantry up and down.
I ended up putting a magnetic digital level on top of the gantry rail so I could see exactly how much its incline changed. Send gcode to slide it up and down, then adjust the eccentric nuts a little bit, then repeat. Once I got it so the level didn't change, I re-leveled the bed and printed a beautiful first layer.
That was almost a year ago and it's been working ever since. I've had to re-adjust the eccentric nuts periodically when things start to get off, probably due to thermal expansion when the weather changes.

Isn't this always the problem with this design . Nine times out of ten it is something with the rollers. Although the printers have a stiff and cheap frame, the motion system (rollers and single lead screw) seem to be the Achilles heel. Thanks for posting the answer, much appreciated, please accept after 48 hours!

Two things:

Did you bring the bed up to operating temperature to do the levelling (manual or automatic). The metal & glass will expand/warp at different levels depending on temp.
Check your G-code to make sure it is not doing a G28 (auto home). That turns off auto-levelling. If it is there you can add:

G28 ;Home
M420 S1 ; turn levelling on
M501 ; reload your last-saved bed levelling from EEPROM

This assumes you saved the results from your auto-levelling with M500:
G29 ; Automatic Bed Levelling
M500 ; save the bed levelling data to EEPROM

I have been bringing the bed up to operating temperature by manually preheating it before starting a print. I auto-home with G28 before leveling with G29.


text:
Bed size and nozzle homing offset in Marlin 1.1.9 firmware
This is driving me up the wall, hope somebody can give me some advice...
I have an Anet A8 (metal frame, so 'AM8').  Bed is the original 220x220 mm.  When the nozzle is at the X/Y end stops it is positioned 16 mm 'west' away from the bed (in free space) in the x-axis, and 5 mm 'north'.
The problem I'm having is with the X_BED_SIZE (surely 220) and X_MIN_POS settings. I keep falling into either the nozzle home a long way from the center (should be 110,110), or getting a message about end stops being too narrow for the bed.  Given my sizings above, what should the following be?:
// @section machine

// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS 0
#define Y_MIN_POS 0
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

Welcome to 3DPrinting.SE!

The original Anet A8 has:

// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -33
#define Y_MIN_POS -10
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

So in your case it would be:

// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -16
#define Y_MIN_POS -5
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

Tuning the bed to print exactly in the middle so that large prints fit on the build plate is described in question: "How to center my prints on the build platform? (Re-calibrate homing offset)".

Thanks a lot Oscar.  I was able to make that change, compile and upload, but it hasn't made a lot of difference.  The homing nozzle position is about 20mm north and 28mm west of the actual bed center.  This was what got me down this road in the first place...  So I downloaded your calibration diagram from thingiverse, and it won't really print because the center is so off.  The weird thing is, when I home the printer is heads off to X80 Y110.  Why not X110 Y110 since that's clearly the center of 220x220?

Looks like I got there, bed centered and compiled as it should:
// The size of the print bed
#define X_BED_SIZE 220
#define Y_BED_SIZE 220
// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -16
#define Y_MIN_POS 15
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS 235
#define Z_MAX_POS 240

@AndyDove Are the endstop locations the same as on the Anet A8 (X on the left and Y on the back when facing the machine)? Note the (0, 0), the origin is the left front. So when the printer homes Y, the nozzle is in front of the bed, so a negative Y value should be used (in front of the bed is the negative Y). Maybe you can add a link to your config and I'll inspect it for you. I also have an AM8, modified to my needs.

Hello Oscar, thanks much and sorry for the stunted replies.  Just in the lounge heading over to Austria (from Detroit) for a week of business so it's been a day of packing.
The printer is working much better.  Stops are exactly as you describe, x on the left gantry and y on the rear right frame.  Works well.
What was throwing me is that when the printer homes, it actually centers the bltouch on bed center rather than the nozzle, but when I print it's now printing dead center so all's good.  I would send you my config, but I left it on my other laptop - some other time!  Thanks again!!  /Andy


text:
Wavy lines on 1st layer only
I'm getting wavy lines on the first layer only in both the x and y direction identically.  The first layer is 0.4 mm with a 0.4 mm tip. The other layers are 0.2 mm.  I've tried changing the Z offset all the way from -1.2 to 0.5 mm.  I've tried changing the hot end leveling the heated bed.  None of these changes affected the wavy lines.  The waves have about a 1 mm period.  The printer is a German RipRap.  The material is ABS.  The heated bed is 110 °C.  I've tried the hot end at 220 °C and 240 °C.  So far, nothing has changed the waves.

Are you sure they're actually supposed to be straight lines?

You have a too thick layer: to get straight lines, the plastic has to be squished together to some degree as it is pushed out of the nozzle. The result is a shape similar to a circle with the top and bottom cut. This works well until your layer thickness is more than 3 quarters of the nozzle diameter - above the "squishing" is practically nonexistent, and if you go above the nozzle diameter, there is almost no way to get the desired thickness out of the nozzle at all.
To aid in depositing the layers, it is also advised to demand a line width that is about 10 % larger than the nozzle diameter. As illustration, this is roughly what 0.4 mm extrusion width with 0.4 mm layer height (blue) and 0.45 mm extrusion width with 0.3 mm extrusion height (yellow) look like:

Now that's some awesome graphics! +1

I would also check this answer as resolving the problem, but only one is allowed and I checked the one who answered first.

@PerryWebb the guideline is to check the answer which you think is the most helpful.

Where did you get the images for this? They're awesome!!!!

@Diesel I made them with Fusion360

They're awesome, I'll have to start playing with Fusion360 more!

The general recommendation for layer height is to go no thicker than 75% of the nozzle diameter. Your post states 0.4 mm layer height with a 0.4 nozzle, exceeding the recommendation.
If your first layer is dropped to 0.3 mm, you'll fall into the recommendation, but the thickness is a reference for ALL layers.

I'll try this out tomorrow. Hopefully, this is the answer.


text:
How Do I Speed up The BLTouch Auto Bed Leveling In TH3D's Unified Firmware?
I have just upgraded my board to TH3D's EZBoard Lite with their Unified Firmware (U2.R1.15) and whilst dialling in all the setting I have found that using the BlTouch each time to be frustrating because of the time it takes to complete the Auto Bed Leveling, however, I cannot find the settings to increase the speed as shown in Teaching Tech's video:
#define DEFAULT_MAX_FEEDRATE          { 500, 500, 5, 25 }

is changed to
#define DEFAULT_MAX_FEEDRATE          { 500, 500, 20, 25 }

and
#define BLTOUCH_DELAY 375   // (ms) Enable and increase if needed

is changed to
#define BLTOUCH_DELAY 100   // (ms) Enable and increase if needed

and
// X and Y axis travel speed (mm/m) between probes
#define XY_PROBE_SPEED 8000

is changed to
// X and Y axis travel speed (mm/m) between probes
#define XY_PROBE_SPEED 10000

I am not quite sure which parts to change as the two builds are organised and worded differently.
In the online firmware configurator, it does list an option to speed up the probing of their own EZABL but says not to do so for the BLTouch in the manual configuration editor
// Super fast probing - VERY EXPERIMENTAL AND ONLY TESTED WITH EZABL PRO SENSORS
// Do NOT use with EZABL_FASTPROBE (comment out above) or BL Touch Sensors
//#define EZABL_SUPERFASTPROBE

Would enabling this be the same as making the changes listed in Teaching Tech's video?
Any help you can offer will be greatly appreciated.

X -> Y Problem:
The EZBoard seems to be supported by stock Marlin too, so that would probably be the easiest solution.

It is not advised to lower BLTOUCH_DELAY, there is time required for the deployment. Note that the sanity check should have warned you: "BLTOUCH_DELAY less than 200 is unsafe and is not supported."

I'm exactly at the same situation, trying to speed up bltouch through th3d firmware. Did you end up solving it? Did it work by enabling #define EZABL_SUPERFASTPROBE?

No, I never found out how to do it because I'm not sure if EZABL_SUPERFASTPROBE will work with the bl touch, I ended it up leaving it because speeding it up wasn't worth it enough to go through the hassle of fixing it if mucked everything up.

This has been changed in newer builds of Marlin.
Previous code:
// X and Y axis travel speed (mm/m) between probes

#define XY_PROBE_SPEED 8000

Current code:
// X and Y axis travel speed (mm/min) between probes

#define XY_PROBE_FEEDRATE (200*60) //define feedrate as a multiple of 60.

There are multiple ways to achieve this:
In G-code
You don't necessarily need to do that in firmware, TH3D is based on Marlin firmware and is just a monolithic implementation for most popular printers and boards that helps novice users to easily configure their printer, but in the meantime it hides other options from plain sight.
Being a derivative fro Marlin firmware, the bed leveling speed in between probes can also be easily set in G-code. G-code G29 has a speed parameter:
S : Set the XY travel speed between probe points (in units/min)
From below (TH3D firmware) can be seen that a value of 12000 mm/min will speed up and is generally safe to use.
In Marlin firmware
In Marlin firmware, the speed setting in between probes is found in Configuration.h:
// X and Y axis travel speed (mm/min) between probes
#define XY_PROBE_SPEED 8000

In TH3D firmware
In TH3D firmware this speed is buried in the Configuration_backend.h:
  #if ENABLED(PROBING_MOTORS_OFF)
    #define XY_PROBE_SPEED 8000
  #else
    #if ENABLED(SLOWER_PROBE_MOVES) || ENABLED(TH3D_EZ300) || ENABLED(TIM_AM8)
      #define XY_PROBE_SPEED 8000
    #else
      #if ENABLED(EZABL_SUPERFASTPROBE)
        #define XY_PROBE_SPEED 16000
      #else
        #define XY_PROBE_SPEED 12000
      #endif
    #endif
  #endif

The speed is depending on setting of the PROBING_MOTORS_OFF in Configuration.h:
// This will disable the XYE motors during probing. Can be useful if you have stepper motors causing interference issues with the EZABL sensor.
#define PROBING_MOTORS_OFF

or depending on the speed settings for specific setting/sensors (ENABLED(SLOWER_PROBE_MOVES) || ENABLED(TH3D_EZ300) || ENABLED(TIM_AM8):
// If you have issues with your machine running the faster probe setting disable the #define EZABL_FASTPROBE below.
// DO NOTE: Most machines will work with the fast probe enabled. Use M48 to verify accuracy.
#define EZABL_FASTPROBE

// Superfast probing - Only works with the EZABL Pro Sensors
// DO NOTE: Not all machines will work with the fast probe enabled. Use M48 to verify accuracy and make sure the Z isn't binding with the high speeds.
//#define EZABL_SUPERFASTPROBE

Basically, if you have not defined one of the following: PROBING_MOTORS_OFF, SLOWER_PROBE_MOVES, TH3D_EZ300 or TIM_AM8, the XY_PROBE_SPEED  will default to a value of 4000 (depending of the definition of HOMING_FEEDRATE_XY) since the constant is not defined, see Conditionals_post.h):
  #ifndef XY_PROBE_SPEED
    #ifdef HOMING_FEEDRATE_XY
      #define XY_PROBE_SPEED HOMING_FEEDRATE_XY
    #else
      #define XY_PROBE_SPEED 4000
    #endif
  #endif

In Marlin you would simply change the value of the travel between probing speed whilst in TH3D you need to sort out if one of all those conditions are met. For advanced users with a slightly different printer setup, the TH3D software might be less optimal. Do note that forks of the Marlin firmware that are heavily modified always (like TH3D) lack behind the original sources; you are dependent on the implementation schedule of the fork maintainer. But, for people that have not modified their printer, have a limited knowledge of software (C/C++ development) and firmware flashing, or their modification falls in the supported options of TH3D, the monolithic TH3D might be very helpful!
Most probably, your setting is overruled later.

I dont know if you managed to solve this but if not I was facing the same issue and managed to do it just by searching all sketches for those parameters in Arduino IDE. They are not all in configuration.h like shown in the Teaching Tech video. Most of them are in configuration_backend.h and some in conditionals_LCD.h I used the values suggested in TT's video and it has speeded up levelling vastly.
p.s. I am using the most recent version of the TH3D unified firmware on a Creality CR-10 mini

Hi, welcome to 3DPrinting.SE! Showing which constants you would need to change would help the OP, the current state of the answer still leaves the OP in the dark...

I was successfull in getting my ender 5 pro bltouch to work faster. I still have some tweaking to do, and I'm a noob. I did the following in configuration_backend.h:
I changed #define HOMING_FEEDRATE_Z 4 times 60 to 20 times 60:
#if ENABLED(EZABL_SUPERFASTPROBE) && DISABLED(BLTOUCH)
  #define HOMING_FEEDRATE_Z  (15*60)
#elif ENABLED(EZABL_FASTPROBE) && DISABLED(BLTOUCH)
  #define HOMING_FEEDRATE_Z  (8*60)
#else
  #define HOMING_FEEDRATE_Z  (20*60)
#endif

XY probe speed looks good, didn't have to change:
#if ENABLED(PROBING_MOTORS_OFF)
    #define XY_PROBE_SPEED 8000
  #else
    #if ENABLED(SLOWER_PROBE_MOVES) || ENABLED(TH3D_EZ300) || ENABLED(TIM_AM8)
      #define XY_PROBE_SPEED 8000
    #else
      #if ENABLED(EZABL_SUPERFASTPROBE)
        #define XY_PROBE_SPEED 16000
      #else
        #define XY_PROBE_SPEED 12000
      #endif
    #endif
  #endif

I commented (deactivated) this, so it probes only one time:
 //#define MULTIPLE_PROBING 2

I changed the folowing from 15, 10, 10:
#if ENABLED(BLTOUCH)
    #define Z_CLEARANCE_DEPLOY_PROBE   10
    #define Z_CLEARANCE_BETWEEN_PROBES 5
    #define Z_CLEARANCE_MULTI_PROBE    5

Hope this helps. Work in progress.
Andy

There's also the option to save the mesh so that you don't have to level each time you print.
First of all, using Cura or whatever you use to send commands, send:
M502; Reset to factory settings
M500; Saves (so that you may start with a clean slate)
G28; Home All
G29; Autolevel

After running your auto bed leveling, add
M500
And you're done.
P.S. don't forget to do this after bringing both extruder and bed up to temperature


text:
How to slice a model to ensure at least a certain amount of filament per layer?
I am designing a part with a material which can bear up to a certain stress.
To keep the stress within the design limits, I need to ensure a certain surface of solid material per layer, in other words a minimum amount of extruded filament per layer and a smoothly changing infill ratio so that the infill can transmit the load efficiently to the neighbouring layers.
The part has an irregular shape and I cannot simply increase the infill ratio for the whole object because the part is big and it would cost more time and filament. I also cannot build straight pillars of solid material inside the part because there are no regions which are suitable for a continuous pillar.
How can I calculate and apply a smoothly changing infill ratio or in general how to ensure that each layer is made of at least a certain amount of material?
I use Prusa Slicer for slicing and Fusion 360 for the design.
Related questions about variable infill, which however don't answer my question because I need to specify the amount of material and because I need a smoothly changing infill ratio:
Different infill in the same part
slic3r: Can I vary the infill percentage for different heights of my model?

Very interesting idea!
There may be a way to do this semi-automatically, but I believe it's not yet a part of any slicer.
My suggestion would be:

Export file as .stl (Fusion 360)
Use a DLP slicer to create images of the layers (CHITUBox)
Calculate the area of each of the images (Matlab - I think?)
Calculate the required infill percentages for having the same mass on each layer (Excel)
Open the model in PrusaSlicer, create a single "height range modifier" (PrusaSlicer)
Save the project as .3mf (PrusaSlicer)
Extract the .3mf file (7 Zip)
Create the neccessary "layer config ranges" texts for PrusaSlicer (Excel)
Inject that text into an extrated .3mf file (Notepad++)
Pack the .3mf file again (7 Zip)
Slice the resulting file (PrusaSlicer)

I think you have a major XY problem. The amount of material per layer is not what determines the part strength. Unless additional material is placed in a manner that reinforces against the stress you're designing for, it's just wasted. Moreover, infill in particular is not terribly useful this way, as infill has to rest upon the support of existing infill below it. If you suddenly increase infill density at a particular layer, it will not provide any significant additional strength because the added lines will be unsupported and will not bond strongly to anything. Even the next layer above them, and the next after that for quite a few layers, will not bond well because the unsupported lines can just bend downward when the nozzle goes over them, rather than providing a surface for the newly deposited material to press firmly against and bond to.
Generally, infill is not your main source of part strength anyway. I would start out (especially if you can test; if this is a one-off thing, the material cost is not going to be an issue anyway and just go with overkill) by increasing the number of wall lines (wall thickness). Walls generally provide the most strength, and the amount of material used will be proportional to cross-sectional perimeter rather than area, which typically will vary "linearly" rather than "quadratically" (I use these terms loosely since I don't know right off how to make it rigorous - what the independent variable should be thought of as being). My usual default (and I believe Cura's) is 2 walls; I would expect 4-5 to be very strong, and as long as you keep at least 15-20% infill, probably stronger than what you'd get by any increase in infill percent.

My idea was to use a cubic or gyro infill, which I expected to be suited for variable changes. Hexagon is surely better for compressive forces like I have, but as you say, it is based on stacking of adjacent layers which would not be my case. I'll think more about the issues you raised.

All types of infill (and FDM deposition in general) are based on pressing adjacent layers together; it's just a matter of whether the new layer 100% coincodes with the lines of the previous one, of whether it's only partially overlapping. But wherever you have lines in the new layer that don't at least mostly overlap with ones in the previous layer, you'll have weaker structure. As a rule of thumb, you want the lines of the new layer to deviate by at most around 1/2 the extrusion line width from the lines below them.

Then the best solution would be to do something like https://www.youtube.com/watch?v=q0YsC53mFvY where solid infill is placed along the lines of stress.

@FarO: That looks like it's using modifier meshes, which only works well if you have isolated parts that can be independently supported to use different infill for. Otherwise, I would skip slicer generation of infill entirely and instead design your model hollow with whatever infill structure you want to use. A cheap approximation of this is just putting very thin gaps inside your model (otherwise leaving it solid) wherever you want to generate walls rather than infill.


text:
3d scan matting spray
I want to scan a few ceramic items that are shiny and have multiple colors and found that using an artec 3d Spider that doesn't really work due to the shininess and thus want to use a matting spray or sth to be able to get proper results. Ideally sth without color that can be used on the ceramic items and allows to obtain proper texture results for the 3d model too. Any ideas?

There are many variations of a product generically known as chalk spray. Some of them should be considered permanent or semi-permanent, while the Montana brand product explicitly states "temporary" in the description. There is a caveat in that it has to be a non-porous surface to be considered temporary.
The product is primarily directed at outside/sidewalk art which can be washed away or will wear away under normal traffic. As such, it is suited for matting shiny surfaces for scanning purposes. White is the best color for scanning as it will accept light and shadows better than the other choices.
I have a can of white and can attest that it will wash off. Some of the product will wipe off dry but the small crevices require washing, which should be considered when spraying your item.

The product is available at many online outlets and may be found at local art supply retailers.


text:
Filament spreading apart and stringy on first layer
I keep having this issue on prints where the first layer has stringy lines that don't stick together.
I've tried the following things

Replaced nozzle and throat
Used new filament (to rule out filament that may have absorbed moisture)
Printed at 180, 200 (my usual temp), 220
Aligned z stop sensor
Tried line width of 0.8 (usual 0.4)
Slowed initial speed to 30mm/s
Increased flow
Different Top/Bottom patterns

My print settings as shown in this pic are the following

Layer height: 0.2
Line width: 0.4
Wall thickness: 0.8
Print temp: 200
Bed temp: 60
Retraction dist: 5.5
Retraction speed: 40mm/s
Initial layer speed: 30mm/s
Cooling at 20% after 0.2mm, 0% until then

Printer

Prusa I3 (hictop)
Cura to slice
Printing with PLA
Have had years of successful prints, issue started happening after a couple months of not using printer
Running marlin
Runs auto leveling routine before each print

Let me know if you think there's other relevant settings to this issue. Any help is greatly appreciated, I've been trying to fix this for days. I've tried different models, large and small, but have the same issue no matter the size

This looks like a mechanical or electronical (missing steps) combined with a too close nozzle to the build plate. Also with correct hair spray or specific adhesion spray you won't need the kapton tape at all.

I would try two things you didn't mention; a bed leveling (this looks a little close) and an e-stepper calibration. The layer looks thin and under-extruded, and two common culprits are the bed height being too close ("oversquishing" the first layer which reduces flow rate and adhesion), and the e-stepper not feeding as much filament as the slicer's asking for (giving you thinner lines than the slicer expected, so they don't adhere to each other or the substrate).
I also see problems with that kapton layer. Totally understandable, the stuff is a major pain to lay down bubble-free, however it's also absolutely necessary to do so to avoid first layer issues. That's not your only problem here but it'll keep being a pain after you have filament feeding sorted out.
Lastly, I'm seeing slicer error; the floor fill is being laid down over the top of the shell layers on the right side of your image. Remember that the wealth of slicer variables in Cura regarding print speeds, flow rate, filament diameter etc ultimately boil down to a single G1 command per line: "move from here to here at this speed extruding this length of filament". So, if the slicer is forgetting where it drew the outline by the time it scripts the floor fill, it's possible it lost the plot on extrusion calculations as well. Alternately, the printer could be the one that lost the plot, either losing track of the steppers or incorrectly interpreting the G-code. Usually you just need to power-cycle the printer, close and reopen Cura and re-slice. Also, if you're printing with a USB cable, try switching to an SD card; there's less to go wrong in the communication between slicer and printer if the slicer tells the printer everything it should do up front.
I'd look into each of these, then try to print a calibration shape, like a 20mm XYZ cube, before going back to the print you had on the plate before.

Thank you so much for the insights! I do have the bed autoleveling each time (forgot this one). I'll give the rest of these a try. I did have perfectly smooth kapton the other day, but in trying to calibrate the height, it faced the wrath of the nozzle making contact with the bed :'(

@Chris consider dumping kapton or other layer in favor of gluestick or gluespray.  Much easier to deal with.

@CarlWitthoft - For some plastics, yes, however if you need a heated bed over about 60*, i.e. ABS printing, kapton's the stuff. ABS adheres well to it, and the tape's own adhesive keeps the layer down on the bed even at 120*C where other bed preps fear to tread. Can't tell you how many times I've had a print pull blue tape right off the print bed, and glue stick/hairspray can both make a real mess of the bottom of your print (which could easily be the top or front of your finished piece) and can lose their adhesive qualities at these higher temps.

@KeithS Great, complete answer! With 3DLAC or Dimafix spray you do not need Kapton for ABS, they increase to adhere more at higher temperatures. I get even POM to stick using such sprays. Whole lot easier to apply.


text:
How to avoid line curvature in first layer of a 3D print
I have a problem with large lines in the first layer of my prints which have curvatures. The last layer has no problems. You can see the problem in the horizontal line of the "A", the rest of the "A" seems fine. Here are example pictures:

close up:

What can that be?

This is printed with an Anet A8.
Slicer: Ultimaker Cura
Layer Height: 0.15 mm
Wall Line Count: 2
Print Speed: 60 mm/s
Printing Temperature: 190° Celsius
Build Plate Temperature: 60° Celsius

Level your bed properly... What is the first layer height? its speed and flow of first layer?

This looks like too much material for the room available; have you tried decreasing your flow maybe 5%?


text:
Remove broken heatbreak
I'm trying to replace my hotend with the E3D Hemera direct kit. I got to the final step of hot-tightening the hot side and managed to snap my heatbreak. The part that screws into the heat-sink is stuck, though I was able to remove it from the heater block section.
Below is a picture of the heatbreak. The red square shows what it in the heat-sink. It's mostly thread (with thermal compound) but a bit of the unthreaded metal is sticking out (above the disk shown).
I've tried removing it with a jeweler's drill (which is how I removed the heater block portion, but I cannot get a good grip on the long threaded piece. I've also tried pliers and rounded needle-nose pliers. Neither worked. I couldn't find my regular needle-nose and will go to the store to try that. Are there other options to break this free or am I stuck with buying a replacement heat-sink? I already ordered a replacement, but it'd be nice to have a backup in case something else goes awry (as has been the case with this modification; this is snafu number 4).

Maybe you can add a photo how much is stuck in the radiator?

I can try when I get home. That's why I included the current picture. In the box only the unthreaded portion at the top is sticking out. (About 1/4 inch of metal)

Broken screws or screws with damaged screw heads are typically removed with screw extractors. Since there is already a hole you could "drill" (unscrew) it out with a screw extractor, as it is counter clockwise, it is about creating enough friction to unscrew it from the threads. Beware that it is not drilling and spalling material, turn slowly.

Alternatively, a grip vice pliers may work if there is enough "meat" to clamp on.

Never heard of the extractor before. Nifty. Are there any particulars that I should concern myself with? Namely the fact that there isn't much metal due to the aforementioned hole and what size of extractor I should purchase. Since the Hemera uses tight tolerances and came as a kit, should I remove the dual gear assembly?

I'm definitely googling how to use an extractor, but I doubt I'll find anything that is specific to 3D printers, asking so I don't miss anything that definitely won't be covered elsewhere.

@LuxClaridge It's all about creating enough friction to unscrew it, you could also fill it with hard wood and use a smaller extractor. Usually you buy them in a set with multiple sizes.


text:
How can I remove my print from the bed safely
I have printed two objects with my new 3D printer (Anycubic Mega S) and everytime, my prints are stuck to my bed (sort of glued to it). I cannot remove them by hand. I have tried waiting until it cools off, but the only thing that works is scraping really hard the bed with the spatula.
I'm scared that if I have to do that for my next prints, I will break the bed (maybe peel off the element that keeps the plastic and the bed glued together while printing).
What is the safest way to remove a print from the bed ?

I'd recommend a different print surface. After struggling like you, PLA printed on blue tape, we printed a box that seemed welded down!  We had to chisel it off the bed, screwing up the leveling.  Fed up with that, we added a WhamBam system to our printer. It has a magnet that is stuck to the aluminum bed, and a sheet of PEX material that is stuck to a sheet of flex steel.  The magnet holds the flex steel/PEX in place while printing. When the print finishes you pick up the flex steel/PEX, give it a little flex, and the part pops right off. I've posted videos in this forum of parts we've done.

A tap with the backend of a screwdriver is sometimes enough to get it loose. You can also consider an adhesion spray, not for adhesion, but for release. I used to do that for printing PETG on PEI sheet, without an adhesion spray/glue stick it will bond permanently.

@CrossRoads I would be very interested in a link of your videos !

https://3dprinting.stackexchange.com/questions/10176/printing-pla-on-pex-surface-is-heated-bed-needed  Two of my videos here

One method that works at our makerspace and also has worked for a user on another 3d printing forum is to use a 50:50 mix of water and denatured alcohol. While the print bed is warm, apply some to the perimeter of the print at the bed surface. Allow it to cool, try to remove the print. If it does not work, reheat the bed and repeat until you are able to release it.

I will try that tonight :D !

I have had good luck using dental floss. If you can get it under the edge of the print, then you can pull it all the way through and prints come off easily.


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Altering the print bed temperature at different layers
I am using Cura for slicing, and OctoPrint for the actual printing.
On small pieces with roughly one square cm of surface area prints over about 6 mm have a risk of coming off at 60 °C.
In fact, I have had to use 71 °C so it stick properly.  However, I don't want the print bed that hot all the time.  I would like to try a different number of layers at different bed temperatures till I get it right.
Gradually, over the course of 1-3 mm, for the bed temperature to decrease back to 60 °C to save on electricity.  Possibly even 50 °C as the layers get higher.
Cura only support the initial layer having a different temperature and that isn't enough.
Apparently you can have custom user events with OctoPrint, one of them being ZChange which is great.
{__currentZ}: the current Z position of the head if known, -1 if not available

I need on the ZChange event to check the __currentZ and execute anM140 with a temperature varying with layer height.  Normally I would use a simple if command or etc., but how do I implement this here.
However, its seems you can execute a command or a G-code.
I can't seem to find any examples where I can test the Z height in layers or mm and execute a different temperature for different layers.
An additional problem is the increased temps cause the model to melt so that the opening is smaller nearest to the glass than most of the rest of the model.
I am height of the raft, which helps, but I am hoping for a compromise.
The print bed shouldn't need to be 70 °C for the whole vertical height of the model.
Any suggestions?

Did you try heating the bed to 70 then starting the print job with a file that has the heat bed at 50? By the time the first layer is done, the bed should have cooled back down to 50.

The actual problem you are facing is bed adhesion, the proposed solution (in your question) shouldn't be the preferred solution to get your parts to stick to the plate/glass as plastic shrinks as it cools down. Note that a 5 °C temperature drop after the first layer usually isn't a problem, but larger temperature differences or shutting off the heat completely will cause your parts to come off the glass.
Note that PLA requires a temperature of about 60 °C (for adhesion as this is close to the glass temperature where the plastic is soft; however, note that PLA can be printed on cold bed surfaces on suitable bed surfaces). The slate of glass is an insulator, so it is perfectly possible that you need to set the bed at a higher temperature to get 60 °C at the surface of the glass plate. When the lower layer deforms the bed temperature is too high.
As you are using Cura, there is a plugin available called TweakAtZ, nowadays this is a default plugin. How to use this is described in this anser (on question "How does one use a heat tower?"); instead of changing the hotend temperature you will need to modify the bed temperature instead (using M140).
To solve the actual problem, you need to prepare the glass by cleaning it properly, use a level bed with a correct initial nozzle to bed distance for Z=0 (usually thickness of a plain paper sheet A4/Letter) and an adhesive like hairspray, glue stick or a dedicated adhesion spray like 3DLAC or Dimafix. I'm using 3DLAC for several years (for PLA and PETG; Dimafix is supposed to be more sticky at higher temperatures, so for ABS for instance) and never had any problems with adhesion on properly levelled beds. See this answer for another user's experience.
An OctoPrint solution using event as you suggest is not recommended. This is the config.yaml, e.i. the configuration of the print server, not a print instance option file. Furthermore, there are yet no plugins that can handle additional code when the head reaches a certain (layer)height. This is pretty tricky if you use Z position detection when the head also can hop, such code should be inserted by the slicer instead.

Related to your question are the answers on question: "Why keep the bed heated after initial layer(s) with PLA (or PETG)?".

You can manually edit the file. Look for the line that has the Z height of your choice, and insert the temp change g-code right above it.
Upgrade to a real slicer like Simplify3D with has an options to set a heater temp at different layers.
Preheat the bed before you print, then print with a bed temp set lower than the temp you preheated at. This will give the illusion of a temp change.

(I for one turn off my bed after the first layer, when I'm printing PLA. I also don't have proper cooling (at this time), my environment is humid (59.9%) and the ambient air temp is 31C.) - just for context


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Extruder temperature failure
I've never made solid prints since I purchased a TEVO Tarantula in December 2019, but since I'm totally new to this sport, I didn't realize I had an issue until after many failures.  I kept upping extruder temperature and nothing seemed to change, parts printed but fell apart.  Using a hand held temperature gauge to check bed and extruder (on the sensor screw), bed temperature was perfect, extruder only warm, stepping 10 degrees Celsius at a time (200, 210, 220, 230, 240, 250 °C) always resulted in 18.3 °C/65 °F
I looked for broken wires on extruder heat and sensor, but they were okay. TEVO support thinks it's a sensor problem, but it won't arrive for 1 month or more. I purchased a spare extruder from AliExpress when I bought the machine and replaced the complete unit but now I get an error E1 Heating Fail, Printer Halted.

Hi and welcome to 3DPrinting.SE!

What sort of extruder did you buy? Does it have a similar temperature sensor (PT-100 or an NTC resistor)? Note that some sensors have a different number (heat-up table) assigned in the firmware, you could have a wrong sensor. Have you tried to power the heater cartridge directly on the Power Supply Unit to see if it heats up at all? What I find strange is that it prints, but it is weak, filament cannot be extruded under 170 °C, so if it got extruded it got hot, possibly you've got thicker filament in the slicer than you have.

The first extruder unit appears to have an error the firmware can't detect, which is why TEVO thinks the issue with that extruder is the heat sensor. If the sensor's reading hot relative to actual temp, the block will be too cool to reliably extrude, while the printer won't think anything's wrong and won't try to heat the block more.
However, I'm surprised the extruder can push any amount of any type of fil through the nozzle at room temp, which makes me think there's also some user error here. Non-contact temp gauges like IR guns can be bad at accurately checking very localized temperature; I'd recheck the extruder at what the printer thinks is working temp, but use a contact thermometer like a multimeter with a thermocouple (the Extech MN35 is inexpensive and works well for most hobbyist uses).
The second extruder has a detectable error. Either the sensor is again faulty, but this time reading 0 V (which usually equates to 0 °C), or the heating element is faulty and can't warm the block. Either way, the printer can command as much extruder heat as it wants, the sensor never gets above room temp much less to operating temp, so the printer eventually gives up and tells you there's an extruder heating problem.
This printer-detected heating error is a little easier to troubleshoot because the printer can help you. If the hotend gets to working temp as measured externally, but the sensor reads well below it, the sensor is the problem. If the hotend does not heat, or heats very poorly (like only getting into the 150-ish range when trying to heat to 200), it's the heating element. Both the heater and sensor could be faulty, but the combination of two failures is less likely by simple probability, and it's easier to diagnose the sensor issue with a working heater, so if the heater's not heating, fix that first.
It's possible, even probable, that a combination of parts from the two extruders will give you a working hotend, however you have to know which parts are working, and those parts have to be separable (as in you can remove the needed part from one assembly and put it in the other without destroying the part or either assembly), which at this pricepoint is honestly not a guarantee. The info provided in the question isn't quite enough to say which pieces of each assembly should be combined to give you a working extruder head, but the above tests will tell you.


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Top layers failing/underextruding on Creality CR-10
For some reason the only the top layers keep failing or underextruding on my prints, for no clear reason. Here are my settings:

Slicer: Simplify3D
Filament: 1.75 mm Black PLA from Filamentive
Resolution: 0.1 mm on a 0.4 mm nozzle
Temperature: 200 °C nozzle and 50 °C bed
Speed: 45 mm/s and 50% outline speed
Infill: 15%

The prints were going perfectly fine on a 0.2 mm resolution and only seemed to fail when I changed to 0.1 mm; which is strange considering the rest of the print goes fine, apart from the top layers (which I have 3 of).
My only thought is that it could be a bridging issue and is somehow underextruding, and getting caught on the infill as that it where it is centred around. I wouldn't know how to fix this.
If anyone could give me any information or tips I would be very appreciative, thanks.
The pictures are taken after some light sanding.

If you decrease layer thickness, you should increase bottom and top layer amount, or set it to a fixed shell thickness. The thinner the layers the more difficult to span over the infill (there is much less filament extruded).
You could try extra part cooling, higher percentage infill, reduced hotend temperature and slower top layer printing. But, best results are reached with more top layers and higher infill percentage.
See e.g. this answer by user "dnewman":

That said, with very low layer heights (e.g., 0.1 mm), there's a tendency to use very sparse infill to speed up printing time.  However, very low layer heights bridge over voids very, very poorly.  So poorly that you can have the print nearly finished only to find that the top won't close up.  Thus, don't make the infill too sparse when doing low layer heights.  MOREVER, you definitely need more top layers to get the final finished top to look acceptable.  The thin layer heights will take many more layers (many more in physical height, not just layer count) to give a nice top.  At issue (again) is how poorly low layer heights will bridge voids.  With 0.2 mm on up, you generally get a nice, thin strand extruded which can stretch across voids. But at 0.1 mm layer heights the printer is just doing tiny, discrete squirts of plastic which it spreads like cake icing across the lower layer.  There's not a single, fine strand extruded and instead tiny little beads.  When there's a solid layer below, these squirts have something to be spread against by the extruder nozzle.  But when there's a void, the squirts just build up on the nozzle and then come off in a big blob when the nozzle next brushes over a non-void space.

The holes in your part tops are the result of a combination of poor bridging and too few top layers.
What's happening is that when the printer tries to lay down the first layer of the top/roof, it has to "bridge" over the top layer of the infill. If you are trying to lay down that layer too quickly, with too hot a filament temperature, over too sparse an infill, the lines won't go down properly, and then the next layer over that has to try to bridge this same gap with very little support (and very often with up-curled broken strands of filament in the way).
The printer can eventually lay down a smooth layer, if you give it enough tries to smooth over the rougher, broken layers underneath. How many you need depends on how badly the first one failed to bridge the infill gaps. If you're only printing 2 layers, try 4. If you're printing 4, try 6.
Also, look at your infill percentage and pattern. The top lines have to be drawn over the top of whatever the layer of infill looks like as of when the slicer calculates that the first layer of top needs to go down. Virtually all slicers provide a "preview" of the sliced layers, with some like Cura allowing you to trace through the extruder's "tool path" over each layer. This can be a very useful tool to diagnose potential issues with what the slicer will expect the printer to do.
As for how to change it, it really depends on what you need out of the part in terms of material strength (different patterns have advantages and disadvantages in how much force can be applied in what directions), weight (more infill means heavier), and print time (higher percentages and more complex infill patterns increase print time). Cubic infill has the best overall strength-for-weight, and it slices and prints pretty fast as each layer is just straight lines. However, it's among the worst in terms of the grid it provides under the top layer. Isolinear/Triangle fill provides one of the better support structures, and is near the top in Z-axis compressive strength, but compressive strength other than in the Z-axis tends to be low. Gyroid infill has among the best combinations of strength, weight and required bridging distances, but slicing and printing the complex curved structure takes more time, and some slicers don't offer it (I'm still kicking around with an old MakerBot that's only fully supported by MakerBot Desktop, which doesn't offer any "fully 3D" fills like cubic or gyroid at all).
Lastly, if you absolutely need the model at a light weight or fast print time that precludes increasing the infill or slowing print head speed, try printing a bridging test, especially something like a "temperature tower" that allows you to see the effects of varying extrusion temperature all in one model, and make sure you're printing at the exact temperature giving you the best results for the other configuration settings you're using. Your model may not require externally-visible bridging or overhangs, but the ability to draw a long line of filament literally into thin air without sagging or snapping is a useful trick even in "solid" object prints, because as you've found out, these solid shapes are up to 90% air inside.

authors: Денис Алексеевич


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Cura is printing support on nothing?
I am new on 3D printing, but I cannot understand how support structures (in Ultimaker Cura 4.4.1) can stand if they do not lay on anything, but air. Throwing everything away after 9 hours of printing is not a good experience, did I do anything wrong?
In the attached screenshots images of the sliced model and Cura settings for support structures are shown.

Demonstration of the issue
Here some pics of the real printing results at 50 %-60 % of the work done. One of the two critical supports was barely done while other one, the same encircled in the slicer model, was not. I saved the printing attaching with some glue an "L" shaped piece of cardboard.

UPDATE 11/01/2020
The tree support option greatly failed, but if anybody could suggest different settings I will be happy to try and report here an update. These are some screenshots:

I've highlighted with red pencil the horizontal pieces of structure supported by nothing. I have to say anyway that the resulting model is worth to Moebius, could be an alien spaceship it-self!!!
I have partially fixed the problem setting the support horizontal expansion to 3 instead 0 mm as suggested by a more skilled friend. Anyway, this is clearly a workaround of an intrinsic bug that appears just with Anycubic printer setting and not with other printers configuration. The drawback of using 3mm instead 0mm is that the supports become too strong and some of them completely envelop model parts.

it might help to know other settings: Print speed, Printer (some have specific issues), nozzle diameter, temperature and material.

The image of the sliced print part is not very clear but printing support on air is a feature of Ultimaker Cura. This is done when support is laid on top of your print part if you enabled Support Placement to Everywhere, which you did. The default Cura setting for Support Bottom Distance (which is a sub-setting of Support Z Distance) is the layer thickness specified in Layer Height. If you have a layer height of 0.2 mm, the Support Bottom Distance is also 0.2 mm. For the top, option Support Top Distance this is two layer heights, so 0.4 mm in this example. These options are visible in the expert mode, you can search for them in the search box, see image below.
Why should you want air in between your part and the support?
You'll soon find out when you want to remove supports, if no gap is used, the support will fuse to the print part. This is only interesting (no gap between print part and support structure) when you use a different filament for support like PVA or break-away filament; e.g. PVA dissolves in water.

Note on the updated printed part images, you seem to have a stringing issue that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid. Maybe fusing the support will help you to slice better supports, or alternatively set option Support Placement to Touching Buildplate and use an experimental option called Tree Support. You can also try to change the print orientation by rotating the print. Last resort is to design the supports yourself in a 3D model software program.

Thanks, I will check the settings you mentioned in the evening and update here for community interest and to confirm the possible real problem on them.

@fede72bari You do not need to update, this is not a forum (SE sites work differently, please take the [tour]), you ask a question and the community answers your question. You only update the question when the question is not clear and requires additional information. Beside an image of the sliced part which does not show the problem very good your question is fine, no need to update! If you want to answer yourself, just post your own answer, that is also allowed! And don't forget to accept an answer and vote when you have gained enough reputation. Welcome to 3DPrinting.SE!

I will check thanks, but supports need to lay on something otherwise it will result in a wrong printing and missing part; I  am adding some images of the real printing in the original post. Clicking on the image to enlarge it the problem is clear, that is the best perspective I could get, it is a very small gap.

@fede72bari Better images are very welcome! Also try to use a different color for support in the images. And yes, support cannot be printed in thin air, but also note that the slicer frequently doesn't correctly make an image of how it is printed, the visualization has its limits. Your support is printed onto the wheel like structure with a gap if I interpret the image correctly.

yes, one support structure have a complete gap on the entire wheel structure where it should have been lean; on the other side Cura avoided the gap between the support an the wheel structure in the last 25%-30% of the bottom support surface and this saved the support itself.

Mmmh there are many things unclear to me I try to summarize:

I cannot understand why the support cannot be "partially" fused on the bottom to a part of the model as it is usually on the top supporting the model itself. On the top is "weakly" fused so that is can be detached "easily", whycannot is on the bottom too?
not all the support laying on part of the model were wrong, some of them correctly hadn't that gap, I try to upload pictures of this too.

you seem to have a stringing issue that needs to be resolved first. Note that it tries to print support on top of inner side of the toroid. if you refer to the "NOT PRINTED SUPPORT" in the picts, that is indeed the problem. Just because there are 0.4-0.5mm of GAP when the extruder tried to do it, it found nothing but air. But it was a problem of Cura, not of the machine. As shown in the very first slicer screenshot.
Thank you again for your support and patience. Hope it helps others too, I saw similar posts in Cura community.

@fede72bari Try enabling "tree support" and "touching build plate" support type and reslice and see what happens. You are most welcome, but at SE sites you express gratitude by voting and accepting questions. Also note that comments are deleted after a while, especially when there are a lot and lengthy. In principle everything is already in the answer, comments shouldn't contain extra information. Hope to see you around!


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Using an Anet A6 3D printer in the UK... (mains voltage issue!)
I understand that this is probably more of an electronics question, but was hoping that someone with experience of using an Anet A6 in the UK (or a country outside of the US/China) may be able to help... or alternatively, someone knowledgeable in electronics!
I recently bought and assembled an Anet A6. I am based in the UK. On the power supply transformer of the Anet A6, there is a switch that allows you to select the input voltage from the mains. There are two options, 100 V or 220 V.
When I turn my Anet A6 printer on, nothing happens... I have triple checked all connections and there doesn't seem to be anything wrongly connected or loose.
I am wondering if the reason it is not working is because in the UK we use a different mains voltage 230 V (I think) and a different frequency 50 Hz (I think) to the US and China (which I assume the printer was built to accommodate)?... I am not 100 % sure on this, just a guess, I am far from an electronics expert.
I don't have a multimeter to test if there is voltage flowing (not that I would even know how to test it lol).
Is it likely that this difference between voltage/freq is the reason that it is not working? If so, is there anyway to fix this? I would prefer to buy something (some sort of converter) than tinker with the electronics, as I have no experience in electronics and live in a rented flat, which I really don't want to burn down (not that I would if i owned it).
Any help is massively appreciated, thanks in advance!

Update
I have done what @Oscar suggested and also bought a multimeter to test the circuitry. I plugged my Anet A6 into the mains power supply and turned it on, but still nothing happens... the LED doesn't light up, not does the LCD screen turn on.
I tested the voltage of the power supply whilst it was turned on across connections 6 and 8 in the video below (taken from the assembly instructions video, 12 mins 46 seconds):
Assembly Instructions Video, 12:46
The 6 and 8 connections correspond to the output from the transformer (ie the connections that would be connected to the mainboard). There was no voltage reading at all when I measured it here with the multimeter. Does this indicate that there is a problem with the transformer/power supply, or is this expected?  Or am I testing in the wrong place and there is a better place to test when the printer is on to determine what the problem might be?

Please add a photo on how you connected the wires!

regarding edit: yes, this means your power supply is busted. Possibly the fuse inside, or otherwise defect.

The UK uses 230 V mains voltage. The 220 V designation is from the past, Europe is now using 230 V. You do not have to worry about the frequency.
You should place the switch to 220 V and plug the cord into the socket. The printer should start immediately booting (cycling) the printer firmware, the LCD should light up and the cold end cooling fan will spin (annoyingly).
If nothing happens, you need to check the Power Supply Unit (PSU) and all cables for proper connection (does the fan of the PSU spin if it has one, you should at least see a led light up). A multimeter is not expensive and generally very valuable to test if it outputs 12 V. That way you know the PSU is working or not, if it works the problem is at the main printer board.
As these PSU's are pretty cheap and faulty, you could well have received a broken one.

How to measure the voltage?
If you look at the connection terminals you will find labels above them. Measuring position 6 and 8 might be the incorrect ones, this depends on your PSU. If you have exactly the same PSU as from the linked video, measuring between 6 and 8 would be correct:

From the image above the connections from left to right (for other PSU units, the order may be different, I have units where the connection to the mains is on the right):

L, N and ground are used for connection to the mains,
COM (stands for common or 0 V) or sometimes denoted as -V is the output ground (negative, connection for the black wires) and
+V is positive, connection for the red wires.

You need to measure the voltage difference over COM and +V, this should be the voltage of the power supply. Ideally you measure the voltage when the power supply is delivering a load (e.g. directly connected to a strip of LEDs or directly connected to the heated bed; some faulty PSU crash in under load, this can be seen by a lower voltage than the rated voltage).
If the PSU is correctly wired, your fuse is not broken, does not have a LED lighted and the voltage is zero the unit is defective.

Ok thanks very much for providing more info in your answer. I have just noticed that I may have wired up the transformer to mainboard incorrectly, but wanted to ask for your advice. In the video, it suggests that the red cable (V+) goes to the negative connection on the mainboard. Is this correct, or should the V+ go to + on the mainboard, and the black (COM) go to - ?

Sounds like you may have wired it backwards, which could have destroyed the board.

I've accidentally done that a few times, but my boards survived, but what @R.. says might have happened, it has been mentioned here at the site a few times. In my defense, the black marking on the board needed the red, the white marking the black...

I wish companies making kits would ship them with keyed connectors (vs just screw terminals or whatever) that can't be reversed without first taking things apart. It would save so much user frustration and avoidable bricking of boards.

@0Scar answered my question correctly, hence why I have accepted his answer. The problem was actually not to do with the switch on the transformer, but was a series of electrical issues that had to be resolved. I have included the solutions to these in my answer below. Thanks to everyone for helping out!

@Oscar was correct, so long as the switch is set at 220 V, the printer will turn on. I am adding this answer to help anyone else who has a similar problem.
I strongly recommend that you buy a multimeter if you have any power supply issues, as this helped me to figure out what was wrong.
There were three issues that needed to be rectified before my printer would turn on. The first was that I had bought a fairly cheap EU to UK plug converter from my local supermarket. This was mistake number one, as the quality was low and there was no ground pin for the power supply (which is dangerous). I plugged the EU plug into my converter, and then the converter into the UK mains socket, and it would not turn on. By using my multimeter I was able to figure out that the converter was a piece of rubbish. With the plug still plugged into the converter, but the converter removed from the mains, I touched my multimeter cable, whilst in continuity mode, on one of the three pins on the UK side of the converter (the bit that goes into the wall), and the other cable onto one of the terminals that I had connected the power cable to the power supply with. I touched each terminal in sequence to see if it was electrically connected to the pin on the converter. I repeated this in sequence and identified that the live pin on the converter was not connected, and so no current could flow when plugged into mains. I immediately defenestrated the converter. Here is the replacement that I bought:
EU to UK converter
The next issue was that the power supply cable was wired up incorrectly (or at least unintuitively). In continuity mode again, I touched one multimeter cable to one pin on the EU plug of my power supply, and the other to one of the terminals (which were connected to the wiring of my power cable.) I discovered that the live and neutral wires of the power cable were wired the wrong way round on the plug (in order for it to be used in a UK converter, not sure what the wiring convention is on mainland EU). In the UK, the right hole in the mains socket is live, the left is neutral, and the top one is ground. On the EU plug I had been provided with, the left pin was live and the right pin was neutral. If I were to plug this in to the new converter in the normal orientation (cable coming out the bottom side), the live and neutral would have been connected incorrectly (plug-live -> converter-neutral, plug-neutral -> converter-live). Hence, in order for the pins to be situated correctly in the converter, and subsequently in the mains socket, the EU plug had to be plugged into the converter upside down (plug-live -> converter-live, plug-neutral -> converter-neutral).
Finally, the official instructions for the wiring of the Anet A6 are wrong. If you follow the youtube video that they provide, you will see that the positive terminal is closest to the bottom of the diagram (on the thermistor/endstop side of the board). Mainboard wiring instructions. THIS IS INCORRECT. Check your board, as the polarity will be printed onto the board. If you wire up the mainboard according to the instructions, your V+ wire will go to the negative terminal of the mainboard and, your positive terminal will go to the COM wire of the power supply. This is wrong, as the positive terminal should be connected to the V+ wire, and the negative to COM.
Hopefully this helps save someone some frustration and time!

Note that e.g. EU plugs in the Netherlands (and maybe more EU countries) do not have a live and neutral convention, the plug can be inserted 180° rotated. Unless you live in a EU country that have a pin sticking out the socket the plug can be inserted 2 ways. For the power supply it does not matter, it is alternating current.


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How to save the post processing scripts configuration with Cura?
I have made a temperature ⨉ fan speed tower which needed 3x9-1 ChangeAtZ post processing scripts and it took me quite much time to configure them all (and check it twice). Is there a way to save this, so that I wouldn't need to make them all again if something went wrong and I needed to start over or if I wanted to do something similar again ?

Have you tried saving as 3mf file (don't know if this works for the script input), I use this to save materials and configuration options. When I reopen the file I delete the STL and load a new one, slice and print.

Yes, I have. It didn't work. Post processing scripts are not changed when I load a .3mf file.

Thanks to fred_dot_u, I found the solution :
the post processing scripts configuration is saved... in the printer profile. So, you cannot directly duplicate it, but re-installing a second occurrence of the same printer will clear the post processing scripts list, you can get them back by selecting the modified one...

I'm a Simplify3D user which allows one to save "factory" files. It appears that Cura supports printer profile configuration and saving.
From the above link, one is directed to enter the profile manager. You can duplicate an existing profile and rename it to separate it from the protected (standard/stock?) profiles.
Without using Cura to confirm this, I suspect that you'll discover this may be the solution you seek.

I have tested this (printer profile level), this does not work, the plugins are not part of the profiles and the storage thereof. Maybe it is the printer profile?

Well, you were right... Except that this is worse than you thought : it appears that those script are saved in the printer profile X-(. Setting another instance of the same printer gave me on with the scripts and the other one without it... I'd like to select your answer, but since it is not on cura, it would need ot make a specific one :-/