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How fast can printer head move without damaging steppers?
Is there any risk of damaging stepper motors if I set too big travel speed?
What is maximum safe travel speed?
My printer is a German RepRap Neo.
I currently use 120 mm/s. Is it safe to increase this value to 200 mm/s?
What would my printer do if I set very big travel speed?

Reminds me of the time when hard disks gave complete control of their insides to the OS - allowing viruses to play happy birthday by smashing the hard disk head onto the disk.  Most places learnt after that to ensure any requests wouldn't result in hardware damage.

Short answer no
We use stepper drivers to limit the current, the travel speed is at capped by the amount of current supplied by the stepper drivers. This prevents the stepper motors from damaging themselves. You can set 200mm/s in the slicer, but you have no guarantee that that will be reached in real life.
One thing to keep in mind though is that setting your travel speed too high can induce artifacts such: shifted layers, ghosting, uneven extrusion, etc. So the best thing is to keep the speeds within the specified limits.

What would my printer do if I set very big travel speed?

If a speed is set above the limits of the stepper, the stepper will stop rotating or stutters.
Basically there are 2 limits, the first is the limit of the board to generate the pulses to the stepper and second, how these pulses are processed by the stepper.
The speed of steppers depends on several aspects, including:

microprocessor speed
stepper driver
micro-stepping setting
voltage
etc.

This reference gives you some more background as well as a table (which is a little optimistic for Marlin firmware) with maximum speeds. Depending on the application in your printer (stepper type, pulley size and microstepping value), it lists some maximum speeds for various boards:

What is maximum safe travel speed?

In case of an Anet A8, 1,8°; 16-teeth-GT2-pulley; 1/16 microstepping, this leads to 160 mm/s on Marlin on an Atmega microprocessor (note this is optimistic).

I currently use 120 mm/s. Is it safe to increase this value to 200 mm/s?

That depends. If you work out the mechanical and electronic details of your printer, you could look up the value you could ultimately use.

Is there any risk of damaging stepper motors if I set too big travel speed?

No there is not, the stepper will stutter or stop. I've had this with too fast retractions on an extruder stepper motor.

Stepper motors contain permanent magnets, which are only really damaged by heat. The coils in the motor are only damaged by high currents that would happen at voltages above the maximum rating of the motor. While it is possible to configure a stepper driver to send enough current into a stepper motor to damage it (either due to heat or over current), desktop 3d printer drivers do not have enough current capacity to do such damage to those NEMA 17 stepper motors. The only thing bad that will happen is that you risk over heating the driver or the components around it on the PCB causing an early failure of the parts. (Google "Temperature Cycling and Fatigue in electronics").
That aside, the only problem that you are likely to encounter is stepper stalling.

A high speed is unlikely to be reached unless you also set a high acceleration, and acceleration is generally more likely to cause a problem (unless you reach the pulse rate limit of the drivers).
High acceleration will increase vibration, and critically requires higher torque from the motors. At some point, the torque will exceed the motor/drive current capability, and the motor will skip steps. As soon as this starts to happen, your print will become unusable.
Before reaching the point of missed steps, you're likely to see other quality issues, but unless you're in a very hot environment, unlikely to see damage to the motor. Depending on the quality and heatsinking of the stepper driver, you might see overheating here (you can check for overheating of the board though).


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Arduino Mega 2560 + RAMPS voltage on GPIO pin
I am using an Arduino Mega 2560 and RAMSP 1.4 shield with Marlin firmware to control my machine (not exactly a 3D printer). Marlin has G-code:

M42 P20 S255 ==> Turn on pin 20 of the microprocessor
M42 P20 S0     ==> Turn off pin 20 of the microprocessor

I am using this command to turn ON a MOSFET switch connected to pin 20.
When I have not put the RAMPS shield on top of AtMega,  this works. Pin goes high only when I send code to turn it ON.
But when I place the shield on top of the Mega 2560 (No 12 V power is given to RAMPS, only 5 V from USB), when I first connect USB to it, I find around 2 V on Pin 20 even without sending the ON command. when sending M42 P20 S0 this goes away (0 V) and get 5 V for M42 P20 S255. Without shield there's no voltage when connecting USB to Mega 2560; with shield there's 2 V on the pin and this causes the MOSFET switch to turn on.
Where does this voltage comes from?
First I thought this must be some noise, so added a 10K pull down resistor (since that is the common value I have seen in many circuits), but it didn't work. But placing a 100 Ohm works. Is this safe?

Connecting a 100 Ohm resistor is definitely not safe. This load is far too high for an AtMega2560 output pin. 100 Ohms at 5 V (when the pin is high) is 50 mA, whereas the recommended maximum for an AtMega2560 pin is 20 mA (and it would be better to stay well below this maximum). You should use a higher value pull-down resistor (at least 250 Ohms, more would be better) or find out where the stray voltage is coming from (it could be an internal pull up on the AtMega, since pin 20 is also the SDA pin which Marlin might enable).

But if it is due to the internal pull up, then voltage should show when measured directly from Mega(I mean with out shield). It only present when RAMPS shield is placed on top of Mega. With out shield voltage on pin is 0, with shield 2 V. No command is given , no power supply (12 V) given to RAMPS board. Only USB is connected on both cases

source: Stack Exchange

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

sort: votes


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How to design gears
I want to create a micromouse project for fun that use 2 20 mm x 8.5 mm (0.8 mm shaft) motors. I have my own PCB as base. I want its built-in gears will be attached to two 3D-printed wheels with gears at the back of the wheels at each side. I'm having hard time to start designing the gears since I couldn't find any tutorial.
(photo for reference and not mine)

My Question:

How to design the gears at the back of the wheel? (I use Sketchup)
Is 3d-printing such small objects possible?

designing is engineering. Is printing possible is here.

About gear geometry: https://www.youtube.com/watch?v=Q-XOM4E4RZQ

I would use OpenScad and probably a library to do this.

Designing gears is very difficult for a variety of reasons. Let me list what you should take into account:

The shape of the teeth are very peculiar, trapezoid shape will not work as the meshing will not be constant. Exact shape is controlled by the pressure angle
In lower number of teeth, teeth shape must be modified to avoid any locks, these are called cutoffs
Reducing the amount of material to print requires careful design, most people simply place circles but they cause weak points.
Herringbone and double herringbone gears improve meshing but are even more difficult to design.

For the reasons stated above, creating gears by hand is next to impossible without special tools. Luckily for those who are searching for it, there are systems that generate gears for 3D printing. This customizer has many options and is very open about the licensing, which is another issue with many scripts. For example, it is explicitly forbidden to print parts imported from the McMaster-Carr Catalogue.
If you use OpenSCAD, this library can create racks to go with the gears.
The parameters of the customizer are explained in the page. The script also contains explanations of every module and function.
Disclaimer: Both scripts are mine, yet I do not earn anything when people use them. I created the library when I was unable to find the gears I needed, published with a relaxed license to help others.

@CarlWitthoft Comments are transient and aren't meant for answers to the question. This would be better as a more detailed answer, explaining a little bit about the customizer.

Added more explanation about the process of creating gears. Better?

@TomvanderZanden bump for Cem

@CarlWitthoft you had said something that was adressed, so I bumped you for Cem :P

There are also several gear generators out there. Correct gear geometry is important for long life and noise reasons.
One thing to keep in mind is that iff you are able to print accurate gears it's easy to print herringbone gears which are not easily machinable with other techniques.
That should cover the how (use a generator and import the geometry). The "is it possible" depends on your 3d printing skills, if possible you need to be able to do 0.1 mm tolerances, elephant footing will make the gear unusable.
That said I was able to print some planetary gears 'in place' (ie. assembled on the print bed) using a raft to avoid fusion of the lower layers:

Spinning the gear printed on raft: https://i.stack.imgur.com/MdfuZ.jpg
Spinning the gear without a raft directly on the print bed: https://i.stack.imgur.com/rQ72S.jpg
The first one is still on my work desk as a fidget spinner because it spins so nicely ;-)

Can you explain the term " elephant foot"  ?

Sure! It's when your first layers squash out. Mostly that's caused by too low nozzle height or to high bed temperature.

Example pictures and solutions: https://www.google.com/amp/s/m.all3dp.com/2/elephant-s-foot-3d-printing-problem-easy-fixes/

I bought a program to make gears and chain gears, but this one looks great!

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


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How to level bed after applying glue stick for bed adhesion
I'm pretty new to printing PETG, and my Creality Ender 3 now has a glass print bed. I've done some research, and it looks like a pretty bad idea to try and print PETG on a pure glass surface for fear of the print pulling chunks of glass along with it.
So, I've looked into various bed adhesion options. I've already used blue tape, but I'll need to purchase some wide stuff, and in the meantime, I want to investigate using PVA-based glue stick. However, one question does come to mind: how can I set the bed-nozzle distance after applying the glue stick layer?
Do I even need to? Will the extruded plastic just crush it into the build plate without a problem, saving me the trouble of lowering the build plate? My normal method of sliding a paper sheet under the nozzle at Z = 0 mm would take the glue stick layer along with it if I tried that.

How much glue do you put on it? I use PVA based spray, barely visible, very evenly spread and no problem whatsoever of sticking paper to the glue layer.
Just level the bed as you normally would and apply a sparsely applied coat of glue, preferably from a spray can. Note that glue stick dissolves in water, so you can distribute the glue with a moist cloth preventing globs or thick layers of glue.
Having printed literally kilometers of PETG on various build platforms (various glass sheets with or without PVA based glue, Aluminium and PEI), chipping of glass is not something I have seen happening (this part is added after comments on adhesion and glass chipping in comments). Perhaps, in case of chipping, if the glass might be of very low quality, then chipping may occur. Whether your glass is of decent quality can be tested, just print on one side, and if it chips you always have the other side. My Ultimaker 3E sheet of glass has a small chip taken out of the surface, but that was caused by not carefully removing the print, tip is to not pry with the corner of a too thick painters spatula, the corner can dig into the glass if force is used. This was not caused by the adhesion of the print but a user error, now, years later and many more kilometers of PETG, no more extra chips are out of the sheet.
Printing on PEI with PETG is another story, PETG just fuses to PEI and is very difficult to remove, a PVA based glue helps, but from experience, still prints were very hard to remove.
Invest in a can of build plate adhesion spray, it lasts long, never gives you problems with adhesion and probably is even cheaper than glue sticks (per mass unit).

Not if you "liberate" glue sticks from the supply cabinet at work :-)

Which is how I intended to do it. Is the layer height of a glue stick application negligible?

@ifconfig Unless you apply a lot of it, it should not be a problem. To get proper adhesion, you only need a very thin film. That is easy with a spray can. Sometimes you see pictures on the web where people use too much glue stick, that is not necessary. You can also use strong hairspray. However, some are better than others and not all brands are the same over the world. I'm using 3DLAC for several years now, that is very good spray.

Hrm, so I see. But you're saying that even if I want to use my giant collection of glue sticks, I should be okay without lowering the bed as long as I don't apply a super thick layer?


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Can snap-fit connector be designed for 3D Printing?
I am new to 3D Printing. We currently have to design in process that I want to finish. The design consists of two parts (top and bottom), the top and bottom that need to snap fit into each other. The arrangement should be similar to the one used in many electronics, for example, the cordless phones in the picture below.
My question is, can such clips be done with 3D printing? Will they last (be used 5 to 20 times) and does the material used for 3D printing make a difference? Is there a material that is particularly good for such snap-fit connectors?
Note that my design will only be a prototype and eventually we would be creating a mold for our product.

yes
You can totally print snap-fit connectors for 3D printing, but you need to keep some things in mind. I assume that since you have looked at these connectors, you have a good idea about the matter, but I nevertheless suggest Angus (MakersMuse) discussion locking devices at the beginning of a tutorial Video on designing buckles.
Your tabs thickness will need to be at least one line width wide at the most narrow point to be printable at all.
Print-Orientation
Another thing besides thickness is orientation. For the strongest tabs, you might want to print the tabs like a C for maximum part strength. Just modeling the part with the tabs, it should print in this orientation then:

This way the bending is not applying stress against layer boundaries but 90° to them, giving even force on each layer. This means that you will need to print parts in awkward orientations just for the tabs usually. You will need lots of support.
You can certainly print in a less awkward position at the expense of strength of the tab, acknowledging that "this is a prototype, we can show you that it closes perfectly like this, though due to FDM limitations we might break the tabs opening it again. So we'll be careful."
prototype-variation of model
Snaples tabs
It might be however easier to print the tabs flat and without the hooks, allowing to do a fitting test, but not a snap-connection. Your benefit is, that you won't have to watch for print orientation, but it won't be locking. Make sure to work with workflow and put the modifications for easy printing/not-locking at the end. Alterations to the general design should come all before this point. Then turn off these steps to create the model that is sent to machining for the mold.
Modular intermediate design
If you need to have working, strong tabs AND a good print, it can pay off to print separate parts that combine into a single piece with a little glue. Maybe the C-clamp is actually a thin bar that is put into the back plate and glued into place or secured with a little friction weld.

The print orientation does not need to be as depicted, it depends on the design, I have created snap fit parts where the snap tabs are printed as if your print was printed from the flat bottom up, see e.g. this thing with a perfect snap fitting.

@0scar adressed

One alternative to parts that combine with glue is parts that combine with a threaded interface. Horizontally printing both the tab (as in your image) and the threaded bolt will result in a very strong part. Threaded holes on the other hand are better printed along the Z axis, matching the direction you'd tend to want for the larger part that the tabs connect to.

authors: Андрей Каюрин


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Loose brass heater block
I recently changes the nozzle on my Monoprice Maker Ultimate 3D printer (first time).  The brass block that the nozzle screws into is free to rotate around an is wobbly.

Loose block video
I can't see any obvious nut/screw that's come loose though.  It could well be that it's not important, but it was definitely tightly attached before it twisted when I removed the nozzle.

I've taken the assembly apart:

Silver bit removed:

The silver looking cylindrical nut (with the flat faces) between the brass block and the black metal plate is the heat break of the assembly. The brass block should be tightly fit to this heat break. You could turn the brass block to get a close fit again. The heat break itself can move in the upper part, black plate, the cold end by the set screw on the side. Some hotend assembly types allow that, this screw is then used to fixate the orientation of the brass block. This type of hotend is not very common, it is a MK10.
Without the brass block it looks like this:

Maybe this clears it up how the block is attached in between the heat break and the nozzle; it is positioned where you see the threads. The screw to position the brass heater block and the heat break is clearly visible.
Don't try to wobble the brass block any further as you will wear out the threads, there appears to be a lot of play already.

Cheers, I've added a photo of the disassembled block.  You're saying that the looseness is definitely a bad thing though and I need to find out what's loose and tighten that?

It just clicked that the hole is where the filament passes and is heated.

@BanksySan I've updated the answer, it should be clear now. Just  tighten the heat break to the brass block and position the heat break in the cold end plate.

Monoprice or ultimaker Mk10?

authors: Елена Журавлева


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How can I avoid jamming in the feeder?
Recently, at work we bought a Guider II printer from FlashForge.
When we try to print models using a high resolution or models with a too high printing time, the feeder gets clogged. And the feeder is too hot. We have concluded that the feeder is getting clogged because the high temperature softens the PLA.
We check the feeder fan and is working fine. How can I avoid the jamming? Pausing the 3D printer and wait a few minutes is not working for us. I don't know if it is a common problem for this 3D printer model.
Edit:
The hotend is an all metal hot end. I can't find more information about the hot end.
In the manual of the guider II flashforge recommend a temperature of 210°C for the head and 30°C for the bed. I have tried different temperatures. The most common temperature I've used is 190°C for the head and 55°C for the bed (I obtain the best results with this temperature).
This is the Hotend used by this 3d printer.

Welcome to 3dPrinting.SE!

This is really odd. I've printed 6 hour prints on my Finder with no problems like what you're mentioning. It sounds like maybe there's a disconnect, like the extruder is pushing out more filament than it needs. Maybe return it?

Finder is a different printer than the Guider II.

@Trish  In this moment, I can't open the 3D printer and take a picture. But  I added a picture of the hotend that I obtain in flashforge web.

That looks in the base relative similar to an e3D v6, but with a very short heatbreak and a proprietary top.

The symptoms you describe hint to heat creep. Heat creep is the gradual increase in temperature of the cold end assembly (cooling fins and heat break). This gradual temperature increase leads to too high filament temperatures and as such premature filament softening. In combination with (large) retraction settings, this can lead to clogging of the nozzle. All-metal hotend assemblies are more prone experiencing these problems; lined hotends have a PTFE lining that also insulates the filament so that it does not soften prematurely like in all-metal hotends can happen. Heat creep is best remedied by properly cooling the hotend (good quality fan, no obstructions or large ducts) and reducing the retraction length (and possibly lowering the print temperature, but you already tried that). You could also contact the manufacturer for advice.

also an exchange of the heatbreak can help

@Trish Yes totally true, hence the hint to lined hotends, but, lined hotends limit the maximum temperature to about 250 ℃, this might be enough for many materials, but poses a problem printing Nylon, high temperature co-polyesters, etc. Good that you pointed it out!

I was thinking a necked down one (E3D style), but a lined one does the trick too

@Trish Thanks. I'm not sure why the Guider II doesn't have an appropiate hotend.  Is there another method to cooling the hotend?

@MauroRivera an all metal hotend is an appropriate hotend, but it needs to be used correctly, that is with lower retraction.

@0scar Thanks a lot. I think that this is my problem. I chose this answer for several reasons. In the flashprint (Slider Software) appaers another parameter called retract cooling. I will try to do test with different retraction length and retract cooling.

Don't know about your specific printer model, but I encountered late print fails with clogged systems due to plastic molten above the heat break due to excessive use of retracts.
Retracting hot material transports heat up into the normally cooled down heat break part.
If you set up a very long retract or retract very often, the amount of heat can surpass what the fan is able to push off and soften the filament above the heat break.
Try adjusting the retraction settings in your slicer and see if it helps on longer prints.

Im using the slicer Flashprint by Flashforge. In the settings I can't configure the retracts.

As Oscar pointed out, this seems to be heat-creep.
What is Heat Creep
Hear Creep happens if the thermal energy deposited in the hotend works up through the heat break and out of the dedicated melt zone, resulting in filament clogging up in the coolend.
Where does Heat Creep come from
Heat Creep is usually a sign of having chosen the settings for the print incorrectly.
The biggest culprit is by having a too high printing temperature. I personally have not yet encountered any PLA that demands to be printed at above 200 °C.
In an all-metal hotend, the flow of filament down the path is a serious contributor or keeping heat-creep in check. So as a result, very low extrusion speeds have to be avoided to allow to keep the melting happening only in the meltzone. As the speed of extruded filament is related to the diameter of the extrusion, it is usually better to stay away from very small nozzle diameters.
The anatomy of the heatbreak is also a factor. Take a look at your heatbreak and then at for example the e3D v6 heatbreak below. As you see, it is necked down between the coolend section (the long part) and the part that screws into the heater block (the short part). This reduces the capability of heat to transfer up through the heatbreak, as $I\propto A =(R_a^2-R_i^2)\times\pi$. If $R_a$, the outer radius, shrinks by necking down the heatbreak, then the whole flow of thermal energy is reduced, counteracting heat-creep. But that has to be designed for.

Another factor that can result in heat creep is insufficient cooling of the cool end. Make sure that the fan that is mounted on the cooling fins spins always and gets 100% of its supply voltage power. Then make sure that it can draw in the maximum amount of air and push it out an unobstructed path.

If the temperature is too high it can charr the plastic, causing jams. There are many reasons for that. If the temperature you have selected is not too high (<200C), then it might be the thermistor not correctly reading the temperature. If you can measure the hot end temperature, that will give definitive answer to that question.
Additionally, some filament contains additives that can get burned even at lower temperatures. I find it every difficult to print with woodfill if it takes very long to print. Some wood chips gets burned and causes jamming.

That is very unlikely, a more plausible explanation would be heat creep.

authors: Ольга Гладкая


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CURA doesn't want print bridges
I made a model for my 3D clock. Model has few vertical holes so I made one layer thick bridge for every hole. In Fusion 360 everything looks fine, but CURA (version 3.6.0) doesn't want to print those Bridges. Why?
The Full Wall is 1.68mm thick(in Fusion), infill is 20%, wall line count is 1, layer height is 0.28mm, the support-bridges are designed to be this thick too.
I'm not sure will be material stable above holes without Bridges.

what's the line width and the width of the wall that should be printed there?

In Fusion walls are 1.68mm. Those Bridges are 0.28mm thick(same as layer height).

layer height is Z thickness, you need to check Line Width, which is XY thickness.

While this isn't quite relevant to the question as asked, it looks like you are attempting to design supports for the top of the hole in your CAD program, which you will then remove after printing. I would not recommend this approach, but instead use your slicer (CURA) to generate the needed supports. These will be placed where they are needed, and should be easier to remove from the model. Alternatively, you can design so that you don't need supports (or as much). In the case of horizontal holes like these, you might make a "teardrop" shape that limits to overhang angle.

@mbmcavoy This "custom made support" is one layer thick(0.4mm), can't be thicker than this. Hole is tear drop shape because slicer cuts end of the hole. Why I did those supports? They use less time and material to print. Also, wall is less than 2mm thick.

It seems what you are intending is one wall thick. What is the reason it cannot be thicker? Is that why you are not using supports generated by Cura?

Regarding the tear drop holes, I don't mean the appearance of your circular hole in Cura with the loss of precision. I mean to intentionally design a tear drop shape in CAD. Make a circle and add tangent lanes up to a point on top. The lines should have an angle of about 45 degrees (depending on your printer's overhang performance.) You should be able to print such a hole with no support needed.

@mbmcavoy Nozzle size? Stock 0.4mm nozzle that comes with printer. Whole model is printable without supports. Reason why I added those "support walls" is because I want to be sure that material above hole doesn't collaps. Not big deal to remove, print etc… Btw layer height is 0.28mm

I guess I'm confused - you can always make a feature larger than your nozzle, just not smaller. You say you can print the model without supports, but this feature is specifically a support - that's what they do; make sure overhanging features don't collapse.

Nomenclature help

A Layer is everything that is printed between the print head moving upwards.

Layer height is how tall each line is. It is in Quality.

A Wall is made up from lines put down next to each other.

line width is how thick a 1-perimeter-strong wall is in the XY-plane. It should never be smaller than the Nozzle Diameter. It is in Quality.

Nozzle Diameter is what is the physical diameter of your nozzle. It is located in the printer configuration.
A Bridge is printing horizontal layers that connect to walls at the sides but otherwise not connected to the printbed or print.

Ultimaker Cura does ignore too thin walls
Your walls are 0.28 mm thick and your nozzle is most likely 0.4 mm thick. That can't be printed at all, in fact, you are way too thin to be printed: a printer should never print any object that is thinner than its nozzle as that is a perfect way to generate clogs.
Atop that, slicers ignore also what is thinner or exactly as thin as the line width. If the line width is 0.4 mm, and the wall is 0.4 mm, it gets ignored. If the wall is 0.45 mm, it is not. This can be remedied by setting the option print thin walls, but you still need to have one line nozzle-diameter as minimum line width - actually it is common to go about 10% larger for better extrusion.
Solution
Strengthen the walls to one line width (usually 0.4 mm) in your CAD-design and activate print thin walls under Shell.

Why? If is layer round(since noozle is round) and diameter of layer is 0.28 mm. Why it can't print 0.28mm wall?

@SilvioCro Layer Thickness is height in Z.

Is 0.56mm too much for bridge?

@SilvioCro I added a nomenclature touchup. 0.56 mm is perfectly fine.


text:
Ender 3 distance between nozzle and bed changing on Y-axis
After I level my Ender 3, the distance between the nozzle and the bed seems fine on both ends, but moving the bed on the Y axis shows that it's increasing and decreasing for three times, which I just cant fix.
This only occurs on the left side - the right side is constant from beginning to end.
Also I've been using three different beds (the magnetic one and two glasses) to make sure it's really something else.
I created this video to demonstrate the problem.
I'm sure that this has something to do with the carriage wheel adjustment, but tightening those did not change anything.
How do I get rid of this problem?

I'm having the same problem on my Geeetech A10m (Ender 3 clone), but the distance changes on X and Y axis. Did you find a solution? I know the bed is not warped, so the answer bellow doesn't work for me.

I switched the carriage wheels and tried to tighten things differently, which really changed the position of the increases and decreases. Tightening them seemed to have the most positive effect.

@Davide if your bed is not warped, then it should be just slanted in one direction or incorrectly leveled.

Messing with the eccentric nuts for the X axis seems to make a difference, but didn't really fix anything. I also noticed a change in the noise the printer makes when the head lifts, as if the vibration from the fans is transfered more to the frame. It almost seems as if the X axis is twisting or something. Or maybe the wheels are just bad...

Your video shows that your bed seems warped somewhat.
Ammount of error
As I assume you did level the bed with a sheet of paper to be 0.1 mm thick, we can estimate the change of thickness. The thickest point seems to be 0.2 mm, the thinnest 0.05. that's in average an error of 0.075 mm for the first layer. If you can live with that, no need to touch it.
Fixing the issue
Basically, if the error is too large for your liking, you need to fix it. To fix it, there are pretty much 2 ways. Remember that the Ender-3 uses 24V when ordering parts!
Fix the part or install a replacement part
If you feel like you need to get it even flatter, you'll need to try to flatten the bed mechanically or replace it. You'll need to be comfortable to remove the BuildTak-clone surface, then remove the leveling screws, open the electronics enclosure, remove some hot glue, unhook the bed.
Then you will need to flatten the bed in some way (grinding the upper side perfectly flat or bending it, replacing it for an entirely flat one).
Then reinstall it, going through the uninstallation backward, and add a new build surface on it.
Switch to alternate leveling method: Mesh Bed Leveling
If you consider yourself to be able to do some intermediate to advanced modification of your printer, you can change the hotend carriage to one that allows mounting a distance sensor and changing the firmware to mesh-bed-leveling.
You'll need to get an induction or capacity sensor (common operation ranges for those are 6-36V, so perfectly fine with 24V) and some way to couple that to the board, most likely an optocoupler. Print a new mounting for sensor and fans.
To install you open the electronics compartment, hook up your chosen 24V-5V coupler as extra to the Z-switch, hook the power supply of the sensor up and run it up to the printhead. Replace the mounting for the hotend cooling fan and part cooling fan and change your firmware. Calibrate the height of the sensor to trigger correctly.
I did flash a bootloader via the ISP on my ender-3 since then, so I can just flash the new firmware via a direct connection.
Last words
In either way, after fixing, you should run a PID-tune on the machine.
Thermal Runaway might or might not be active, depending on your firmware iteration, so you should update it anyway, which might make Mesh Bed Leveling the slightly easier way to go.
This has nothing to do with the bed carriage wheels, as the bed hangs onto the carriage only via the screws in the corners.

With that average error being so small mounting a sensor seems to be the best/easiest/cheapest(?) option and there are several videos on YouTube on mounting such on an Ender 3.

@LuxClaridge True. Note though, that Mesh Bed Leveling isn't that simple to set up, it is what I would consider intermediate or advanced thing, as you need to flash firmware and substantially modify the machine.

Though it's getting easier. TH3D's Unified Firmware includes the Ender 3 and one only has to uncomment a few lines (as opposed to changing Marlin directly). Either way, modifying the machine has to be done, I think adding a mount is a lesser mod than potentially replacing the bed.

@LuxClaridge well, I think replacing is "simpler", but gave a rundown to both variants.

I managed to get rid of the problem by installing a linear rail for the y-axis!

Used this mod from thingyverse: https://www.thingiverse.com/thing:3064275
There are also solutions out there which are placing a linear rail on the left AND right side, but since for me the problem was only on the left side, this seemed sufficient (and was).

Blue Painters tape on the left side starting at the center and leaving a band on the far left side and the rear Perfetto side. I checked the before and after and the thickness of the tape shimmed out the deflection on the plate. It sounds like whatever the use to stamp the steel out is creating the bend we are only talking several thousands of an inch but when I put a flat edge on the plate and shined a light from the rear I could see daylight. The blue tape was from Nearys video on creality cr-10 bed leveling.

congrats on introducing a step on your bed...


text:
Why did my printer's nozzle dig itself into my print?
I just completed my first print on my Ender-3 and when the print finalized itself the nozzle didn't elevate itself to clear away from the piece. I watched as the nozzle slowly lowered itself into my print and destroy it. Here is the gcode generated by Slic3r used:

; Filament-specific end gcode
G4 ; wait
M221 S100
M106 S0 ; turn off cooling fan
M104 S0 ; turn off extruder
M140 S0 ; turn off bed
G91
G1 F1800 E-3
G90
G1 Z{z_offset+min(layer_z+30, max_print_height)}{endif} ; Move print head up
G28 X0 ; home x and y axis
G1 Y180; Remove Print Position
M84 ; disable motors
M300 S2600 P100; Beep
; filament used = 24040.5mm (57.8cm3)
; total filament cost = 0.0

You are using incorrect commands in your end-code for the incorrect tool with respect to the print head raise.
Slic3r has no knowledge of the maximum printer height (as in variable max_print_height) because there is no input field to specify this, as can be seen in this partial screenshot:

However, in Slic3r PE (Prusa Edition), there is a possibility to enter such a value, as seen in the following partial screenshot:

Note that in both editions, the Bed shape interface is equivalent when Set... is pressed:

To use the raising of the head, respecting the maximum print height, in Slic3r PE, you need to add the following line:
{if layer_z < max_print_height}G1 Z{z_offset+min(layer_z+60, max_print_height)}{endif}

This will parse fine in Slic3r PE, but not in Slic3r (as max_print_height is not known).
If you want such a command in Slic3r, you need to enter (for a printer with a maximum print height of 240 mm):
G1 Z{[z_offset]+min([layer_z]+3, 240)}

results in Slic3r for a 20x20x20 mm calibration cube with a zero z_offset to:
G1 Z23

But there shouldn't be a need to change the Z-pos at all!  Once the print is done, the head should be able to clear the last layer applied and move to X=0,Y=0 . No need to do anything else, right?

@CarlWitthoft Have you never seen the straight ironing line that some slicers generate over the top layer? Raising the head prevents that.

@Oscar  I have to admit I have not.  Certainly a good reason, then, to do a small relative-Z move first.

Your print end code should have read something akin to this:
; Filament sy end gcode
G4 ; wait
M221 S100
M106 S0 ; turn off cooling fan
M104 S0 ; turn off extruder
M140 S0 ; turn off bed

; End code
G1 F1800 E-3 ; retract 3 mm
G1 Z30 ; Move print head up 30mm
G28 X0 ; home x and y axis
M84 ; disable motors
M300 S2600 P100; Beep

The problem with your end code is the G90 for absolute measurements together with the formula G1 Z{z_offset+min(layer_z+30, max_print_height)}{endif} to set the height. The printer itself doesn't calculate anything. That what it doesn't interpret, it ignores, interpreting that whole thing as something crazy like G1 Z30 to force the printer to go to Absolute 30 mm above absolute 0. To fix it,  your slicer would need to calculate {z_offset+min(layer_z+30, max_print_height)} for the printer - which seems to come out to 30mm above the print and then an if-statement that is not started anywhere.
Going up 30 mm can be much easier be done by staying in G91 ; relative measurements and calling G1 Z30 to go up another 30 mm, though this might be too high for the printer frame.

The G-code in the slic3r reads:
G90
{if layer_z < max_print_height}G1 Z{z_offset+min(layer_z+30, max_print_height)}{endif} ; Move print head up
I notice that 'if' statement doesn't seem to be present in the output G-code file. Is this the problem?

@JonathanGallant-Mills yes, it is a problem. you should also have some else... or just skip that

The same thing happened to me several years ago. My print was a fairly tall part for my delta printer, about 220 mm. In many previous prints, the print head would always go up after finishing, but what I didn't know was that the Slic3r finish print routine specified an absolute Z height of about 200 mm. When the tall part finished, the still-hot print head moved down and ruined the top of the print.
After figuring out that the routine had an absolute reference, I replaced it with a relative movement 20 mm up. It's worked fine since then. An easy fix.


text:
Anet A8 & BLTouch not homing Z
I have an Anet A8 with Marlin Firmware 1.1.9 and I installed a BLTouch sensor. When I start the system the BLTouch does its self test (extend and retract the probe twice) and then lights up red. When I "Auto Home", it homes X, then Y and then extends and retracts the probe and moves up a few millimeters. Then with the probe retracted it moves down until the nozzle crashes into the table. The same happens when I select "Level bed".
Safe Homing is active.
What am I doing wrong?
My current Configuration.h can be found here.

You must invert the logic of the endstop Z_min.
define Z_MIN_ENDSTOP_INVERTING true
To
define Z_MIN_ENDSTOP_INVERTING False

@lukaspanic If your table is colliding with the nozzle, you must invert the Z motor cables

Nope, that didn't change anything. It's still doing the exact same thing. If the BLTouch would be extended it would probably be fine but it doesn't seem to know it's supposed to do anything.


text:
How to specify rotation origin in openscad
OpenSCAD has rotate function which rotates the body around its origin axis.
Is there a way to specify an arbitrary axis?
For example, this rotates a cylinder around its center:
rotate(a=[90,0,0]) {
  cylinder(h=10,r1=10,r2=10);
}

How to make it rotate around its edge?

Found a duplicate on stackooverflow https://stackoverflow.com/questions/45826208/openscad-rotating-around-a-particular-point

rotate() always rotates around the origin of the object following it.
What you can do is to move your cylinder away from the origin, like this:
rotate(a=[90,0,0]) {
  translate([0,10,0]) cylinder(h=10,r1=10,r2=10);
}

You can use the following module in your code to achieve what you wish:
module myrotate(a, orig) {
    translate(orig)
    rotate(a)
    translate(-orig)
    children();
}

myrotate([0,0,90], [0, 10, 0]) {
    cube([10, 10, 25]);
}

myrotate([0,0,-90], [0, 10, 0]) {
    cube([10, 10, 25]);
}

color([1, 0, 0])
cube([10, 10, 25]);


text:
How to set Z-probe boundary limits in firmware when using automatic bed leveling?
In setting up a probe for automatic bed leveling, the limits of the probing area must be entered in the firmware of a 3D printer.
When using a sensor, how do you define the bed limits for the sensor in Marlin firmware?
E.g. the Marlin (1.1.x) configuration.h contains the following inactive statements:

  // Set the boundaries for probing (where the probe can reach).
  //#define LEFT_PROBE_BED_POSITION MIN_PROBE_EDGE
  //#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE - MIN_PROBE_EDGE)
  //#define FRONT_PROBE_BED_POSITION MIN_PROBE_EDGE
  //#define BACK_PROBE_BED_POSITION (Y_BED_SIZE - MIN_PROBE_EDGE)

How do you set the values for the constants of your custom setup? Is this generic or specific?
Probe positioning is defined in the Marlin configuration as:

 *      +-- BACK ---+
 *      |           |
 *    L |    (+) P  | R
 *    E |           | I
 *    F | (-) N (+) | G
 *    T |           | H
 *      |    (-)    | T
 *      |           |
 *      O-- FRONT --+
 *    (0,0)

The probe could be placed with a positive or negative X and Y value. Considering this position, how to setup the sensor bed limits?

There are a few questions on this topic, so a more generic solution would be informative and will prevent multiple questions of others when their sensor has a slightly different location. This answer intends to cover any position with respect to the nozzle. It also does not matter what kind of sensor it is, it can be 3DTouch, BLTouch, inductive, capacitive, etc., as long as you are able to determine the offset to the nozzle (center to center).
For now, it is assumed that the nozzle can only reach the complete area of the bed, no extra space. So unless the sensor runs of the bed, the nozzle limits are used, otherwise the sensor limits the nozzle with respect to the sensor limits. This is the safest assumption and will prevent the carriage running into the end mounts. But if there is more room for travel, an additional offset may be added to the limits.
First, determine the offset of the sensor (e.g. by measurement or taken from the information of the printable sensor bracket found many share sites on the internet; Thingiverse is a good source for such brackets).

HINT for Marlin 2.x
Note the version (branch) of Marlin! The answer is written at the time of the 1.1.x branch and as such is perfectly valid for the latest 1.1.x (1.1.9) version. For the 2.0.x branch of Marlin, different constant names are in use, and a different strategy is used (more simple for setting up). The constant names are not found in the Configuration.h, the answer (and the theory) is still helpful. Constant probe offset values are now found in Configuration_adv.h:
MIN_PROBE_EDGE_LEFT
MIN_PROBE_EDGE_RIGHT
MIN_PROBE_EDGE_FRONT
MIN_PROBE_EDGE_BACK

HINT for Marlin >= 2.0.6
Since version2.0.6 MIN_PROBE_EDGE_* has been renamed again.
Now it is:
PROBING_MARGIN_LEFT
PROBING_MARGIN_RIGHT
PROBING_MARGIN_FRONT
PROBING_MARGIN_BACK

Note that in Marlin 1.1.x the boundaries are set in absolute positions while in Marlin 2.0.x it is described in offset values from the bed edge.

Sensor Offset
The position of the sensor is set using the following constants:

#define X_PROBE_OFFSET_FROM_EXTRUDER [XXX]   // X offset: -left  +right  [of the nozzle]
#define Y_PROBE_OFFSET_FROM_EXTRUDER [YYY]   // Y offset: -front +behind [the nozzle]

where [XXX] and [YYY] are offset values that specify the center of the sensor with respect to the nozzle. If both are positive values, the sensor is located in the back-right, if both negative, the position is front-left (as seen from the front of the machine using the definition in the Marlin configuration file). The other positions that are possible are the back-left and the front-right (one positive and one negative value).

HINT for Marlin 2.x
Note that in Marlin 2.x, these constants are replace by an array definition:
#define NOZZLE_TO_PROBE_OFFSET { XXX, YYY, ZZZ }

Where ZZZ is the Z offset. If you use the old constants, the sanity check upon compiling will throw an assertion that these constants are not in use anymore and should be removed.

Second, let's set the sensor area limits!
Sensor Area Limits
In the following images, the nozzle, the sensor and the offsets are defined by:

There are four possible positions of the sensor, this results in the following schematics for the sensor area limits (transparent red area):
1. Sensor at the back-right:

This implies that the sensor can reach the back and the right borders, so the limits are set by:

#define LEFT_PROBE_BED_POSITION (X_PROBE_OFFSET_FROM_EXTRUDER)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE)
#define FRONT_PROBE_BED_POSITION (Y_PROBE_OFFSET_FROM_EXTRUDER)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE)

Note that if a minimum probe offset is defined by #define MIN_PROBE_EDGE [value]  in the configuration (to account for sensor width/dimension), the bed limits are changed resulting in (where t = MIN_PROBE_EDGE):

Limits are then set by:

#define LEFT_PROBE_BED_POSITION (X_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE - MIN_PROBE_EDGE)
#define FRONT_PROBE_BED_POSITION (Y_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE - MIN_PROBE_EDGE)

In the following sensor position placements, this offset for MIN_PROBE_EDGE will be accounted for.
2. Sensor at the back-left:

This implies that the sensor can reach the back and the left borders (for zero MIN_PROBE_EDGE), so the limits are set by:

#define LEFT_PROBE_BED_POSITION (MIN_PROBE_EDGE)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE  + X_PROBE_OFFSET_FROM_EXTRUDER - MIN_PROBE_EDGE)
#define FRONT_PROBE_BED_POSITION (Y_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE - MIN_PROBE_EDGE)

3. Sensor at the front-left:

This implies that the sensor can reach the front and the left borders (for zero MIN_PROBE_EDGE), so the limits are set by:

#define LEFT_PROBE_BED_POSITION (MIN_PROBE_EDGE)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE  + X_PROBE_OFFSET_FROM_EXTRUDER - MIN_PROBE_EDGE)
#define FRONT_PROBE_BED_POSITION (MIN_PROBE_EDGE)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE + Y_PROBE_OFFSET_FROM_EXTRUDER - MIN_PROBE_EDGE)

4. Sensor at the front-right:

This implies that the sensor can reach the front and the right borders (for zero MIN_PROBE_EDGE), so the limits are set by:

#define LEFT_PROBE_BED_POSITION (X_PROBE_OFFSET_FROM_EXTRUDER + MIN_PROBE_EDGE)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE  - MIN_PROBE_EDGE)
#define FRONT_PROBE_BED_POSITION (MIN_PROBE_EDGE)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE + Y_PROBE_OFFSET_FROM_EXTRUDER - MIN_PROBE_EDGE)

This should have tackled the basics for defining the sensor area limits. It becomes a little more complicated when there is extra travel space. A very easy use of extra travel space can be found in the configuration file; e.g:

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS [XX]
#define Y_MIN_POS [YY]

where [XX] and [YY] are offset values from endstop to origin (orange arrows represent X_MIN_POS and Y_MIN_POS):

Results in offset constants for a back-right probe:

#define LEFT_PROBE_BED_POSITION (X_PROBE_OFFSET_FROM_EXTRUDER + X_MIN_POS + MIN_PROBE_EDGE)
#define RIGHT_PROBE_BED_POSITION (X_BED_SIZE - MIN_PROBE_EDGE)
#define FRONT_PROBE_BED_POSITION (Y_PROBE_OFFSET_FROM_EXTRUDER + Y_MIN_POS + MIN_PROBE_EDGE)
#define BACK_PROBE_BED_POSITION (Y_BED_SIZE - MIN_PROBE_EDGE)

For all other options, a similar addition of the homing offsets can applied.
A similar addition is possible if the print head is able to travel further on the X or Y axis at the other ends of the axes.

Thoughts for solution for Marlin 2.0.x
As I mentioned earlier, Marlin 2.0.x uses bed edge offsets rather than absolute positions. In analogy of the previous graphs we can draw a bed limits diagram (the example below assumes a back-right mounted probe!):

Note that the offsets from the edge need to be defined, to properly do this we need access to the definition of the nozzle offset:
#define NOZZLE_TO_PROBE_OFFSET { XXX, YYY, ZZZ }

As this is the part that defines the array values, you first need to make an array (note that this is a simple solution that many people should be able to understand with limited programming skills, more elegant solutions use the XYZ struct to access the X, Y or Z properties):
Note that Marlin 2.0.x automatically adjusts your probe area based on the defined offset and the MIN_PROBE_EDGE defined for all 4 sides of the bed.
see:
#if PROBE_SELECTED && !IS_KINEMATIC
  #define MIN_PROBE_EDGE_LEFT MIN_PROBE_EDGE
  #define MIN_PROBE_EDGE_RIGHT MIN_PROBE_EDGE
  #define MIN_PROBE_EDGE_FRONT MIN_PROBE_EDGE
  #define MIN_PROBE_EDGE_BACK MIN_PROBE_EDGE
#endif


text:
Creality CR-10S Pro 3D printer heated bed turns off after first few layers: normal?
When I run prints on my Creality CR-10S Pro 3D printer (using Ultimaker Cura as slicer), I set the heated bed to around 70 °C for PETG. after the first few layers, the heated bed set point changes to 0 °C.
Is it normal for a 3D printer to turn the heated bed off during a print, or is this a problem?
I have had some parts warping, and wonder if this is a potential cause.

Maybe you could add a link to the G-code file that you are printing? Which slicer do you use? To be sure, the print commences after the temperature is lowered, or does the print stop?

To those saying that bed heating turning off during a print is not normal, please do not spread this misinformation. Note, Michael and Lewis' replies regarding the CR-10S "ECO Mode". Also Ultimaker Cura has an option to change bed temperature after the first layer.

No, this is not common behavior, and yes this can cause your prints to warp or detach from the build plate.
The question is whether you instructed this (by accident) or not (e.g. it can be a result from slicing or some economy mode of the printer). This should be clear if you look into the G-code file that you print. The typical commands that concern bed heating are M140 and M190.
Please note that this a generic answer to find bed heating operation in your G-code file. Other answers, e.g this one and this one hint to a specific ability of the printer that shuts off the heating of the bed when it is working in an economic mode. Note that this is printer specific.

Cr-10 S Pro has an eco mode make sure it's not turned on because this will turn your bed off after the first few layers have printed.

Very interesting, could you please expand the answer where that "eco mode" is found?

If you start a print there is an "Adjust" button, that will take you to a screen where there is an option "Economic". It that is left on it will turn off the bed heater during the print.

The heat bed turns off because economy mode is set to on by default, change this in the adjustment menu.

Hi and welcome! As most of the information has been provided already, you might want to highlight that this is the default setting, as none of the other answers have stated that. Is it really the default setting? I haven't used this software, but if there is a "Reset Defaults" setting, does the "Economy mode" get set to ON again?

I do have the CR 10S Pro as well and for me it does the same but only because it's a setting in the slicer I enabled. Make sure you check the slicer settings to make sure it is not a setting which is turning it off.
Personally I do let it cool down after 10 layers since it does save energy, and I've not seen any negative effects because of it when printing PLA. Have not yet tried PETG or ABS on this printer.

For PLA that is right, but some materials (ABS) hate that and react with bending considerably.

For clarity, what is the setting called?

This seems like an awful idea for PLA too. If you don't need heated bed for PLA, just don't heat it at all to begin with. Cooling it down mid-print will encourage detachment from the build plate more than just never heating to begin with, and can also encourage warping.

I specifically tried this to combat corner-curling in the first few tens of layers after the bottom, and found that, for prints with lots of small non-connected components in the base layer, turning off the heated bed after the first layer made them all start curling up like shrinky-dinks. If it does work, it's definitely highly dependent on the geometry being printed, and should never be on by default.

That is not normal behavior for the heated beds. I don't have that exact model, but when I print the heated bed will stay to whatever temp was set in the slicer program. Unless you override it manually on the printer itself during the print. I would check slicer settings ensuring temp doesn't change after it's first layers.

I have a new CR10 max.
I can't find any adjustments for the bed temperature settings other than the basic ones in the Creality slicer. I'm not sure if the latest software has got this facility.


text:
Slicer settings for easy support material removal
What are the best settings for Ultimaker Cura to have support material that's easy to remove for my Anet A8. I have printed an object with two different spools of PLA (same manufacturer just different color). The black print was printed with 200 °C, the grey one with 210 °C both a flow of 100 %. Thee black print seems like it has a little over-extrusion while the grey print has some under-extrusion artifacts despite the higher printing temperature. The grey support was really hard to remove and looks super messy the black one not so much...
What would be better settings?

Could it be that the material is so much different despite same manufacturer? The black one seems to flow much better than the grey one. Both have suggested temperature of 210 °C

BTW the thing is 33x25 mm in size. It's rather tiny that makes printing it somewhat awkward...
I have finished another print with a brim and a different support setting (Cross with 50 %) and at 195 °C and an infill rate of 100 %. The support came off much better, the under-extrusion is minimal on the layers however for some reason the top layer does get messed up with open spots and the little nob at the corner was just a a mere stringy stumb that fell off instantly and the walls of the holes came out spongy while the layers of the ring and the long side are smooth and fine...

settings are pretty much printer and material dependant.

The grey supports are much harder to remove because of the higher temperature caused the support to fuse to the print. You need to adjust the gap between support and print and print at lower temperatures.

@0scar do you happen to know where the settings for support gap in Cura are?

You should also include your support settings. I find that the default settings work fine and require little-to-no post processing.

What speed do you print?

@0scar various 30, 50, 60 mm/s

Cura has some settings for the support structure which may help.  Somewhere in the full Preferences menu is a setting for "gap at top" or equivalent wording.  If you increase that gap slightly, the support material will be less strongly bonded to the part.   Be careful, since a huge gap could lead to bridging problems.

Note that the gap is in increments of layer height

From the picture, I suggest printing with 200 °C, as the grey print lost its cohesion at a higher temperature.
Why higher = worse
A filament is a solid that turns into a highly viscous fluid under heating and the more you heat it, the less viscous it gets. However, it also has a very high surface tension, which means, that as it extrudes and if it is not pressed down immediately, then the filament goop will thin as the head moves, resulting in under extrusion and stringiness. Print temperatures from manufacturers have to be seen with a grain of salt, as the measurements are calibrated to their test printer, which is not your printer.
Support Structures
To get good support structures, the support needs to:

have enough surface to not topple over

in case of thin towers, use a brim

The density should be enough to carry but not enough to stick too well

I have had best experiences with 5 to 10% support

don't support angles that don't need it

45° is safe, 70° is on the very hard side. I go with 50 to 60° usually.

In a related manner, make sure that the minimum layer time is set to at about 5 to 10 seconds, which allows the single tip to cool down a little and get better prints
Print Geometry Analysis
The part you want to print is quite complicated with the different Z-heights to start at. It might be possible to increase printability by including "sacrifice blocks" of material about 1 or 2 layer heights below the print, pretty much including a support structure into the print design itself. This way the bottom might get better supported.

Well the model needs support almost everywhere. On the one side there is this center ring (it's sort of a holder for a button) which is lower than the frame, on the other side there's this small rod. So the frame is always lifted above the surface. But since it's laying flat, the support doesn't need a brim or raft. The problem is just, that the support sticks too much to the frame and I can't get it removed clean. That problem did not happen with the black model so I wonder if it's the filament...

I'd suggest trying at 195 C as well -- might find somewhat cleaner layers.

@user6329530 can you show the model in 3D? sometimes there is a better rotation than first thought - and yes, 195 can be worth a shot

I added a screenshot from blender

@user6329530 what's your infil and top layer pattern? I would use concentric only for the top skin, and the levels below in a criss-cross pattern, 5 tops

The infill is just 100% with line pattern. The top layer pattern I didn't change at all (lines), I just made the top line to 0.5 to have a thicker top wall. The top thickness is 0.8 What would be a better setting?

Could it be that a greater layer hight gives less holes? I printed it with 0.1...

@user6329530 For that thing I actually would include predefined support into the print design...

@Trish What do you mean with predefined support? I have the support being generated by Cura using their Cross preset.

@user6329530 as in designed in blocks that have a clearance to the object. It is a trick that sometimes generates better adhesion and print - include a waste object that has one layer height clearance to the actual object and covers the whole base under the object.


text:
Extruder calibrated, but prints still oversized by .1 mm or so
I've got a pretty straightforward problem. In general my printer is very accurate for the XYZ movements. What I'm running into is no matter what size my print is, the XY dimensions will be thicker by around .1 mm. And it's not just the external walls, but interior walls as well.
I have run single and double wall calibration prints to check my extrusion multiplier and they all check out correctly. I know that there is an XY compensation option in Simplify 3D, but I don't like it because quite frequently it results in a drastically different slice.
I know that cooling can cause a part to contract and distort, but this seems to be something different. It's very uniform all around. Is there another way to address this during slicing instead of the XY compensation? I definitely don't want to make the adjustments in my models because that results in a bunch of annoying math I don't want to get into.

So are you saying when you run the single and double wall tests, the wall thickness turn out fine. But when you print an actual part the walls are off by .1mm?

Yes. My walls are printing the expected width when doing the single and double wall tests. It's when I start having infill that the problem shows up.

You could try turning down the infill overlap setting to see if this helps

What infill density and what infill/perimeter overlap percentage are you using?

What extrusion multiplier you use?

@Davo - infill % doesn’t seem to effect it but typically 15%. 20% overlap. Trish - I’m using .96 for a multiplier. That’s both the default for my printer in S3D, and the number I get when calibrating my extruder.


text:
Extrusion test cube resulted in one wall being thicker
I calibrated my extruder according to the mattshub tutorial and printed the extruder calibration test cube with 2 perimeters of 0.4 mm. So the walls should all be 0.8mm thick but only 3 are close to 0.8mm and one is about 0.93 mm thick. The pictures are one turn, walls following each other are side by side:

Update 1
I printed a solid, smooth calibration cube with 1 Perimeter of 0.45 mm, 0 top/bottom layers and 0 % infill, as suggested and got 0.56 mm,
0.65 mm, 0.79 mm and 0.54 mm

I believe that the thickest side is the one where the layer ends and retraction is done in the corner before layer change. Maybe retraction settings?
Update 2
After setting the Extrusion Multiplier to 70%, I got wall thicknesses of 0.89 mm,
0.86 mm, 0.81 mm and 0.96 mm on a 2 Perimeter print of the same object.
Update 3
Fudging with the steps per millimeter changed them from 428 to 306. The resulting one perimeter test was 0.59 mm, 0.46 mm, 0.42 mm and 0.39 mm, pretty much spot on safe for one wall being fat and one thin...
I print at 215 °C with 5 mm retraction to increase strength and get stringing in check.

Let us continue this discussion in chat.

Why not that test print?
You don't want a print constraining your walls to 0.8 mm, since you don't want to print with 1 nozzle diameter for better print quality. Atop that, slicing can induce errors that increase the thickness of walls without us noticing it in the slicer view. Two sources of error (once for each wall)
means an additional 10% error, which would bring the wall as you got perfectly into the expected area: $0.8\text{ mm}\times 1,1\times 1,1=0.968\text{ mm}$
Let's Troubleshoot!
You might not have calibrated the extrusion multiplier correctly, or the steps/mm might be off, or other print settings shoot us way off. Let's make sure to find the source.
Filament extrusion multiplier

use a solid cube as a base, for example, https://www.thingiverse.com/thing:38108
set line width to 0.45 mm to counteract errors from die swell and get a better print result in general1

$d_\text{line width}=0.45\text{ mm}$

set the number of walls/perimeters to 1

$p=1$

set infill to 0%
set top layers to 0
set the extrusion multiplier to 100 %
print the cube (or half of it, Z-height does not matter too much) with no top and infill and 1 perimeter
re-measure the walls

Done that? Math time to calculate the correct multiplier for the filament! The average wall is easy:$$d_\text {average}={\frac{\sum_{i=1}^4 d_i}{4}}$$ $$\frac{d_\text{line width}\times p}{d_\text {average}}=\text{Extrusion multiplier}$$
Remember, that the result is not in % but a float point number! 1 is 100%. So you fill in that value times 100 into the extrusion multiplier.
After this, repeat the whole process with 2 perimeters.
1 - further reading: Why is it conventional to set line width > nozzle diameter? & Slicer line width vs. extrusion multiplier for layer adhesion?

Steps/mm
Make sure to test the extruder against the heated extruder, then repeat the calibration as your tutorial explained.
For some tests, let's fudge to some degree: Trying a filament dependant value of steps per millimeter can help to try to find other sources of errors easier - it makes them at times more pronounced. So we just multiply our steps/mm with the extrusion multiplier that we calculate the way outlined below. For 428 steps/mm and the numbers from Update 3, this gives about 306 steps/mm. This is not a proper calibration, but a means for troubleshooting. After fudging with the parameters reset the extrusion multiplier to 100%, we just want to check what influences our thickness.
Other print settings

215 °C is way hot. Even if it can increase print strength in solid prints, it is usually better to print at 200 °C and less.
Reduce retraction, possibly to 4 mm or maybe even 3 mm.

Lower temperature and less retraction should get prints more consistent, as pressure changes in the nozzle are more consistent. Remember, we are playing with the settings here.
And now Properly
Back to Calibration!
After all the fudging and probably making everything worse, we got to make sure to properly calibrate, those settings will be WAY OFF, in fact, we might go back to the original steps/mm or higher:

Note the current steps/mm as $s$.
Mark the 150mm from the extruder intake. remember if you marked on the close or far side... or simply cut the filament as exact as you can.
Heat the hotend
send a G1 E100 F100
Measure the distance to the extruder intake afterwards as $d$ to get the actual extruded filament $e$. Make sure to measure the same side of the marking!
$(150-d)=e$
$\frac{s\times 100}{e}=s^*$ as the corrected steps/mm
send M92 E###.## with ###.## taking the $s^*$
send M500 to store the value to the EEPROM

Extrusion/Flow Calibration
Now, go back to print a single filament extrusion multiplier calibration, as above. It should be somewhat close(er) to 100% now.
Slicer Fault?
Note that not all Slicers are equal: some slicers are better and more consistent in the results than others with the stock settings, and even with the same settings results may varry. For example the line width for the same settings with Simplify3D and Cura or Slic3r Prusa Edition can differ. The reasons for this are hard to find exactly, but they are most likely rooted in the different slicing processes and optimisation. Sometimes it is some setting that might be overlooked that results in line width variations.
The Slicer world changed a lot betwene 2015 and 2019, and even if you got fed up with one slicer years ago, now it might be worth a shot to test it again. See if you might get better results with other slicers, as for whatever reason, your slicer might cause the issiues, whih allows you to hunt down setting dependant items.


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Linear guideway with Ball screw for X, Y ,& Z axes
I'm building a 3D printer for bio medical application and looking for different opinions on motion system. Build volume 400x300x250 mm
I'm thinking about using Linear guide way with ball screw Linear guide way with ball screw
Would this mechanism be good for a 3D printer.
I'm als0 thinking about using Closed loop stepper motor and Closed loop driver
There'll be two X axes and Y will be mounted on that.
Z axis will be able to move Up and Down

good is always together with a certain application: as X or Y or Z drive? Do you need to enclose the drive system or not? do you need fast printing or is slow ok? What level of precision you need? All these determine what kind of motion system you need. A rough sketch of the drive system would be nice too - as a note there are 2 common ways that are proven: Core-XY (the bed lowers along Z, the printhead moves in the XY plane) and Portal designs (the bed moves in Y, the printhead on an X gantry, the gantry moves up in Z)

In my design, Bed is mounted on Z axis, which can Up and Down, and extruder moves X & Y direction. As per the specifications of linear guide way + Ball screw, if I use 1610 ball screw it can reach up to 160 mm/sec.

That's a Core-XY setup (or similar to it).

What's your suggesion for using something like this for X & Y axis


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E3D V6 PLA prints leaning / not square
When printing a 1 cm test cube after upgrading to the V6 the cubes are tilted ever so slightly. This does not happen with the stock MK8 hotend, or when printing with the V6 with Polycarbonate+Carbonfiber, so it is not a mechanical problem; it seems to be limited to PLA.
Searching forums for this is no help as everyone says to check to make sure the frame is square, etc..
What would cause this? Thanks!
A picture has been added, but it is difficult to see the problem in the picture because of the inherent problems with photographing shapes in general, but here are some examples. The grey is PLA and the black is PC+carbon. The black one is acceptably square while the grey is not. The picture may not accurately convey this but trust me.
I have tried slowing the speed down, everywhere between 60-20 mm/s, it did not help. Temp between 180-210 °C, bed between 60-70 °C.
For the PC+carbon the temp is much higher of course, around 260-270 °C and the bed is 90-100 °C, print speed 40 mm/s.

Also, what printer, print speed and temperature? What kind of infil and perimeter settings do you use? It looks like you also overextrude the PLA. Different materials use different settings - what forks for one material does not work for another.

The tilting is only on the V6, it does not happen with the MK8 hotend. This is an E3d problem and one I can’t believe is unique to me. Also the overextension is due to the flow settings which must be increased to get a good first layer, also limited to the v6 with pla, but that is unrelated to the tilting. And that is another thread entirely


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mjpg_streamer, Octopi, Kubuntu
Running my Flsun 3D Cube from a Kubuntu PC using Octopi, and trying to get my webcam to work with it. I've followed the instructions on Github for mjpg_streamer to the letter. Everything I've read says, "Sure! The Raspberry PI directions will work with Linux, you bet!" but they don't, at least, not for me, a beginning level Linux user.
I know that my webcam works with Kubuntu since I can load it and view it using VLC, but I've been unable to figure out how to get Octopi to read the stream from VLC (the documentation could use some improvement) or even confirm if the stream works.
Back to mjpg_streamer: when I issue the command
export LD_LIBRARY_PATH=. ./mjpg_streamer -o "output_http.so -w ./www" -i "input_raspicam.so"

I get
bash: export: 'mjpg_streamer': not a valid identifier
bash: export: '-o:' not a valid identifier
bash: export: 'output_http.so -w ./www': not a valid identifier
bash: export: '-i': not a valid identifier
bash: export: 'input_raspicam.so': not a valid identifier

I don't know what I don't know, and I don't know how to proceed. The goal is to view my webcam in Octopi/Octolapse on a Kubuntu PC. (Windows with Yawcam, no brainer; Linux, not so much.)

Going to post the answer here for posterity and for those, like me, trying to cope with Linux after making a career in Windows.
I'm running Kubuntu 18 because I didn't want to have to buy an operating system or install a bootleg copy of Windows. The most important thing for a Windows user to know is that the readme.md file is important. Think of it as a .chm file, or a series of linked help documents. What you want to know is THERE, not on the github page.
Using the following command in the mjpg-streamer-experimental directory got me where I needed to go.
mjpg_streamer -i 'input_uvc.so -d /dev/video0 -r SVGA -f 30' -o 'output_http.so'

e.g. webcam, 800x600, 30fps to http (port 8080 is the default) The MD files break it down. I also found two web pages very useful:
http://skillfulness.blogspot.com/2010/03/mjpg-streamer-documentation.html
https://wiki.ubuntuusers.de/MJPG-Streamer/
In OctoPrint the streaming setting is then:
http://127.0.0.1:8080/?action=stream

In my case, I use the network IP rather than local host so I can monitor the print from my upstairs PC. For snapshots:
http://127.0.0.1:8080/?action=snapshot

I'll admit that Octolapse doesn't work for me yet because I'm still trying to work out ffmpeg, but that's another issue. EDIT: got that done, too. Useful command:
whereis ffmpeg


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Path of a nozzle crosses over itself
I built my first printer couple of days ago. I started printing small models (20x20 mm max.) and everything was alright at first. However, when I tried to print a bit larger models, I started facing a problem. The nozzle keeps hitting the path of a previous layer or even current layer. That then causes jams, and the whole layer shifts 5-10 mm in the X or Y direction. I tried using different layer heights (from 0.08 mm to 0.44 mm), adjusting the speed of print but that did not help.

Can you tell us what printer you're using? Is it a clone? What Marlin version are you using? Can you also put in what your settings are and which slicer you're using?

I'm am using a DIY Cartesian based 3D printer, with latest versions of marlin and slic3r. I am using pronterface to run the G-code. I have T8 threaded rods with 8mm pitch for the z axis and two GT2 belts for the X and Y axis. I also have 0.4mm nozzle with 1.75mm filament. I tried a few different Slic3r settings:
Layer height: 0.08 - 0.44mm
Fill density: 20%-70%
Fill pattern: Triangles, rectilinear and honecomb

The heat is set to 205 degrees for the extruder and 40 degrees for the heatbed (It says so on the fillament packing)

Usually, when you have a problem like what you're saying, the problem lies with how you are slicing it, not with the machine itself. I wouldn't be looking at layer height or stuff like that, but how does the slicer make its path. I believe slic3r allows you to see the path virtually before you try to print something. You might want to take a look at it from that direction to see if you can tell what's causing the issues.

Please back this up with pictures of the failed print, sliced print in the slicer, link to model.

I know of no slicing software which produces crossovers in a given layer.  My guess is you're either not getting sufficient adhesion to the bed or insufficient Z-axis motion per layer.

It could be the Motors are stalling and missing steps. Home the Z Axis, send it to the top limit, then send it back to 0. Does it return to the correct location?

At my printer (Anet A8) if there is a crossover it just runs over this, whit noise and jerking, but it stays in the programmed path. Layer shifts by this problem sounds like the motors just missing steps aka. to less power. IDK but some printers have potentiometers for the motors so you can regulate the power so they are less noisy or more powerfull, and maybe noisless motors sounds good in the first place but are not powerfull enough to handle little resistance.

@CarlWitthoft: FWIW, I arrived at this question because I have the same issue. During the first layer of the print, a loop is printed approximately the size and shape of the base of the print, but then a brim is printed over that, but for the same layer. This results in crossing of the path, and defects where the crossings happen (the current path breaks, and sometimes the path being crossed gets dragged). This is on a brand new Prusa Mk3.


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PETG Sticking to Nozzle
For a while now, my AmazonBasics PETG filament has been working like a charm. Now, it is balling up on my nozzle. I've tried slowing it down, re-leveling the bed, etc. I don't want to go through the hassle of replacing my nozzle with a Micro-Swiss all metal 0.4 mm nozzle. I've tried the other extruder which I know works with PLA, but same results. I'm using a Flashforge Creator Pro(2016).

Please add pictures and more information (by [edit]) when this happens, e.g. on the first layer or after a few layers. If it is a layer adhesion problem, maybe this question may help you.

It could be that you're having issues now due to the filament absorbing moisture. I had a big problem with it doing that when I had waited for a few months after opening my filament. Dehydrated it using just my heated plate and a foil lined box over the top and it fixed it right up. If that's something you haven't tried yet perhaps that is what is causing you some grief.

Welcome at 3D Printing.SE Kaleb! You must have had a ventilation hole or something to get rid of the moist air?

PETG does this. PETG is like glue when soft this is why when you level the bed you have to add an additional 0.1 mm distance for PETG. PETG should not be as close as PLA, but futher away. It will stick to the hotend so preferably change the hotend from brass to a nickle plated nozzle (e.g. Micro Swiss, PETG does not stick to that nozzle at all).

I've printed kilometers of 2.85 mm PETG filament, but never needed an increased first layer height or an extra clearance between nozzle and bed. I guess it is depending on your setup. It may help, but it could be it also works without such measures.

Nice, I will change my nozzles I have a bunch of them since one year ago waiting to assembly my third printer and the new ones.

Its the makeup of PETG, it is a stickier thermal plastic and you get better results if you increase the distance, slightly, between the nozzle and bed. Maker Muse and Tom both suggest the same thing in their YouTube videos. When I print with PETG, I never get any stringing at all and it prints just like PLA. I get near perfect prints with zero cleanup or stringing at the end. When I do figures of any kind I use PETG instead of PLA.


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Hooking up an optocoupler in a 24V Machine, is a 2 kOhm resistor sufficient?
I am going to buy an inductive probe for my Creality Ender 3 to enable ABL (Automatic Bed Leveling). And now, I have one last question left on my mind:
I am going to buy a Vishay Optokoppler Phototransistor SFH610A-1 DIP-4 Transistor DC.
Is it sufficient to put a 2 - 2.2 kΩ resistor between the input of the octocouplers LED side and the 24 V Output of the probe, to lower the current and voltage enough to work with the octocoupler? Or do I need something else?
On the transistor side, I will simply attach the 2 wire Z-endstop cable, +5 V on Collector and GND on Emitter.

Possible duplicate of Inductive Sensor in 24 V machine?

Capacitive sensor trigger distance depends on the amount of moisture in the air and as such are not very accurate for a range of operating conditions. A 3D touch sensor is more reliable when using glass. Furthermore, using a higher voltage for powering the sensor has been asked before

Ok, so, I should use an inductive sensor then, right? Because, I do not have other options.
Additionally, I know that there are similar questions, but I am unable to answer to them. So sorry for making a new thread :/

Ok, last question then: I am going to buy the mentioned octocoupler. Is it sufficient to put a 2 - 2,2 k Ohm resistor between the input of the octocouplers LED side and the 24V Output of the probe, to lower the current and voltage enough to work with the octocoupler?

ok, with the changes it is clearly a different question - though I would use a proper optocoupler board...

Where do I get a proper optocoupler board from? I am somewhat limited to conrad.de and maybe ebay.de and amazon.de

TL;DR
Yes, a 2 kΩ resistor is sufficient to limit the current to about 12 mA through the optocoupler. With a maximum current specification of 60 mA you require at least 400 Ω; any resistor in between the values should be suitable for this optocoupler component when used at 24 V. More information is found below.

Having a glass bed and using an inductive probe may not work optimally. In such cases a 3D touch sensor is a very good alternative. For inductive sensors, remember that these sensors optimally detect steel, aluminium is harder to detect (about 60 % less than iron; a glass sheet in between the bed and the sensor requires you to acquire a sensor with a large detection range, e.g. 8 mm or more. To optimize the detection distance such sensors need to be powered to the maximum voltage they can handle (usually 36 V) or the highest voltage you have available (e.g. power supply 12 or 24 V). To protect the board, that is only allowed to receive up to 5 V, an optocoupler is an excellent way to guarantee the separation of voltage levels.
Considering your questions, it is fair to assume you are not an experienced electronics tinkerer, purchasing an optocoupler module is the best alternative, you just screw the wires into the respective input screw terminals as shown in this answer.
As the optocoupler separates two circuits, you can safely use 24 V on the one side and the 5 V on the other side, you do not need an additional resistor when you use a module board. If you plan to buy separate components to build your own circuit, you need to look at the maximum current that the optocoupler can handle on the input side (that will be 24 V). From the documentation from the optocoupler one reads that it is limited to 60 mA. A maximum current would therefore require a resistor of:
$$ R=\frac{U}{I}=\frac{24}{60\times10^{-3}}=400\ \Omega $$
My 12 V optocoupler module uses a 1 kΩ resistor implying a 12 mA current. In your case allowing 12 mA of current yields a 2 kΩ resistor.

Ok, so when I understand this correctly, I do not need to use as much as 2 k Ohms, as e.g. 400 Ohms would already be enough. However, it should be better for the optocoupler, if I use some more resistance, isn't it? I would say, 1 k Ohm should be a good value... As I do not want the maximum of 60 mA to flow.
One question to the linked thread and the wiring: There they connected the Black Signal Wire and the Golden +12V Wire to the input of the optocoupler. Why is this? I mean, I want Signal and GND, don't I??


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OpenSCAD 2018 Command line
First, I'm using Linux Mint 18.3 (Sylvia). Until now, I've been using OpenSCAD with the GUI and never experienced issues. Now I try to start OpenSCAD from the command line, but it always opens an empty file, even if a file with the specified name exists.
Since I have a rather big script, I'd like to generate the STL's via the CLI. Due to this error, I can not even do any tests for parameter passing.
What I'd like to do is to issue a command (flom the command line or in a shell script) that says "Set objectID to 1, render and export the result to stl".
Here is my M(N)WE:
// test.scad

objectID = 2;

if (objectID == 1)
difference(){
    cylinder(d=20, h=50, center=true);
    cylinder(d=16, h=50.2, center=true);
}

else if (objectID == 2)
difference(){
    cube(50, center=true);
    cube([35,35,70], center=true);
}

Any help will greatly be appreciated.

If I understand the question right, we are right at the edge of where it is 3D printing and starts to be programming, but still inside: getting the STL is clearly on the OK side imho

Did you run a full cmd-line, e.g. openscad test.scad -o test.stl ?

Everything in the GUI works fine.

Yes, I ran a full command line and got an error "could not open file" although the specified SCAD source file exists (copied file name from ls output).

have you tried a fully qualified path?

I could finally solve the issue. Calling openscad from command line with parameters does NOT work with the AppImage I used. It works fine with a "standard" installation, though.
Thanks for your support.

did you ever figure out how to do this with the AppImage or just abandoned it and went to a different installation type?

You can specify variable values from command line using:

openscad     ...\
             ... \
             [ -D var=val [..] ] \
             ... \
             ... \
             filename

See the OpenSCAD Manual.


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CubePro Duo Filament Cartridge Replacment Problem
So I just got this CubePro Duo and the guy we bought it off had 3 filament cartridges to go with it, two installed and one spare. The one spare was white PLA while the two installed were colored ABS so I wanted to try out the white PLA for printing so I followed all the instructions on the printer up to put the cartridge in and now its stuck on "Material Validation" step and just isn't doing anything. I followed everything as closely as I could and even started over again in case I did something wrong but it still won't "validate" the material?
I have no idea what's going on and I would really appreciate some help, thanks in advance!

The CubePro Duo is a discontinued 3d-systems printer. It uses their standard proprietary cartridges to prevent to use other filaments. In comparison to other printer filaments, their filaments range between 100 and 150$ per spool, which is listed as "1 kg" (though if that is with or without casing is not clear).
From what I could find out about the cartridges, they should contain some kind of identification method to the printer. That it is stuck in Validation means, that it might not be able to read this. So let's try installing the cartridge again, following the handbook p.17!

Take out the cartridge
boot the machine
wait for the machine to ask for filament
remove the thumbscrew so the filament spool inside the cartridge can turn
pull out the 30 cm
cut 5 cm off the end
insert the material into the Bowden tube of slot 1
push the material till you get some goop coming out
mount the cartridge into the slot, make sure it is clamped in tightly.

This should start the validation of the material, at which point you might get told that the colors don't match the print defined colors. Should the cartridge not be validated again but works on the ABS cartridges, the validation method might be broken on this cartridge. Should it not recognize either, the firmware or the detector might be broken.


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Magnetic heatbed options - can I trim these to size?
I'm looking at options for removable heatbed surfaces for my Prusa Mk2 clone, which has a MK42 bed, 250x210mm
I have a removable spring steel plate at the moment, but it is not dependably flat - there are often issues with patchy filament adhesion or oversquashing, as it has bumps in it.
I'm looking at a magnetic solution instead.
Does anyone have experience of this type of stick-on magnetic surface?

Any drawbacks?
Can I trim it to size? I can't see any which are 250 x 210

I have a spring steel plate but it is not dependably flat -> wouldn't that result in a bumpy magnetic plate when you stick it on?

This magnetic surface would be in place of the spring steel plate, which is removable. I'll edit the question as that's not clear.

Adhesion and sizing
First of all, the product you link is very likely a BuildTak clone or a similar product. My Ender 3 came with a similar one and I have changed to a different one after I ripped it off accidentally to mount a similar one. I have yet to find a sheet of this material that you can't cut to size, as it is pretty much only a polymer with a strong tape on one side and a rough surface on the other. So trimming is not a problem at all.
Mounting
To mount your new surface, you need to get a surface onto your heatbed that has

good contact on all the area
securely holds the bed in place
is as flat as possible

So you surely want to get a metal sheet that is as flat as possible to mount your surface on. If your bed is heated, your mounting method needs to transfer the heat as good as possible, so a direct contact to the heated bed would be good. This, however, rules out most thin magnets, as these magnet sheets demagnetize under heat, limiting the usability for higher temperature materials, for example, ABS. The original Prusa uses a spring steel bed and high-temperature magnets embedded in the heating platform to work around this.

OK, yes I'd forgotten about the PINDA probe - it needs a metal surface to sense proximity. In my heated bed there are 9 metal inserts for this. And obviously it wasn't a problem when using my metal sheet. Would this be a problem if I put BuildTak on my heated bed? If so perhaps I should be looking at a replacement removable metal sheet instead of this magnetic surface?

@Lemmy I don't see it making problems with sensing as it is usually less than 1mm thick, making no problems with the sensors

OK, thanks. I wonder if that is also the case with this kind of product, as it is in two pieces, one which adheres to the bed and another removable one which sticks to the first magnetically. I'm looking for a solution with a removable plate.
If I want to print ABS it seems like I will need high temperature magnets. I've only used PLA so far but would like to have the option to use PLA in future.


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PLA wood filament: a special treatment?
PLA wood has a beautiful natural texture that I wanted to try. But when I used it in my second print, it clogged the nozzle (solved). I know this filament is composed of 70 % PLA and 30 % recycled pine wood fibers.

Are there special indications for this kind of filament?
Should I modify the temperature, or other settings?

Related: https://3dprinting.stackexchange.com/q/14402

PLA and wood fibres = wood filament
Most wood filamet consists of about 60-70 % PLA and 40-30 % wood fibres. This basically implies that PLA temperatures should be used. It can be printed with standard 0.4 mm nozzles, but it is adviced to be printed with a larger diameter nozzle. A larger nozzle will less likely to cause nozzles to clog (more area for the fibres to pass through).
Basic printing advice
Start experimenting with relatively large layer heights (0.25-0.3 mm layer heights). Printing speeds should be held high to ensure relative short residence times in the hot end (in the range 50-80 mm/s). Short residence times prevent   degradation by heat resulting in clogging. It is best for wood fibres filled filaments to not have the filament to stagnate (e.g. pausing). A higher retraction speed and distance might be needed because the filament usually is a little more runny compared to plain PLA.
Beware
After printing, you should retract the filament from the hotend so that during next printing jobs heat up cycle, the filament doesn't degrade and clogs the nozzle. Alter the end script G-code and also use priming scripts at the start and/or do not forget to use a large skirt of multiple lines or a considerable length. As always, you shouldn't leave the printer unattended, regularly check the printer and shut down the printer when there is something wrong, e.g. not extruding. Also note that wood filled filament is reported to be abrasive to brass nozzles, a (hardened) steel nozzle or a Ruby nozzle should mitigate wear problems.
Basic settings
These settings have proven to work, but are not a guarantee, these settings should provide a reference to start experimenting on your own printer:

Temperature: 190-205 °C
Layerheight: 0.25 mm
Speed: 50 mm/s
Minimal layertime: 8 s
Bowden type extruder

Retraction speed: 40 mm/s
Retraction distance: 5.5 mm

Direct extruder

Retraction speed: 25 mm/s
Retraction distance: 1.3 mm

I would add that deliberate changes of hotend temperature during a print can cause varied darkening of the extruded material (carbonization), and if done well looks almost like grain lines in real wood.


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CubePro Alternative Slicer
So, having bought this cube pro duo 3d printer a few days ago I have come to see how significantly limiting the default slicer software that comes with the machine is. For the prints that I am doing I've been looking around at alternative slicers however the cube pro has its own file format for builds and I'm not sure if any other software has the option to export those specifically and I also have no idea id the CubePro can read any files other than its own. On top of this whenever I download some other slicer it gets to the printer setup and there's a whole bunch of settings and parameters for the printer that I haven't been able to find, stuff like Firmware or Nozzle Diameter (Something that id expect to be easy to find).
In particularly a software called IdeaMaker is what I'm interested in since I've seen that you can make custom supports and that would be very useful for what I'm doing.
Does anyone know what I can do? Or is this a case of there's nothing I can do without some serious modification that I'd rather not do?
Any help is appreciated thanks! :D

The consequence of a 4000$ printer being locked down like that should be a refund.

As far as I understand, the CubePro 3D printers use their own format: .cubepro or .cubex.
It appears that a:

.cubepro file format and found out that it only does a Blowfish ECB encryption of the .bfb file

This implies that you need to find a slicer that outputs .bfb tool path files (similar like G-code files) and a tool to encrypt the tool path file. The dubious CodeX tool and this alternative can do that for you.

It doesn't work on firmware version 2.00 in cube pro trio - any idea what to do ??

firmware version 1.10/V2 in cube pro trio is not working for me.  @baressa did you happen to find anything?


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Sparkmaker SLA resin not curing
My model layers are printing much as I expect but the parts when removed from the plate are very soft and flexible and fail to harden any further in sunlight or UV lamplight.  A tall or slender part will bend and distort under its own weight while printing.  I am using LCD-T resin, I have increased time and reduced thicknesses and am now using 0.04 mm layers at 20 s and 255 brightness with no improvement.
Can anyone suggest what I need to change?

Could it be something wrong with the raw resin? How are you storing it (temperature and lighting conditions)? How old is it?

can you run a hard-test of the resin by pouring a tiny sample onto a glass surface and leave it out in the sun? Don't tough it though

This has nothing to do with post-processing.  If the part is sagging in the chamber (or when removed from the plate), then the cure-time per layer (illumination time) is probably set  too short.

It might be the case that the resin separated into layers in the tray. Try mixing the resin well in its container.
I have also heard it can help to filter the resin prior to mixing.

Thank you folks.  The issue was bad/old resin and left in the tank too long.  Replacing all my stocks with fresh and following rigorous stirring and decanting I now have resin curing well during the print.
Sorry to have taken so long to get back to it.