Pulse XE TPU printing settings
First I think those speeds are all too fast - even for Nylon. I just started dabbling in flexibles and therefore use Nylon as an example. There are 3 speeds to consider with any material and you should pick the slowest of the 3
1.) is the max speed at which the printer can operate without having too much vibrating. I think on the pulse that is 60mm/sec so do not go above that
2.) there is the max speed the layers can bond well. For Taulman 910 that is about 30mm/sec so you should print that below that. Most manufacturers will list that for HIPS its around 90-100mm/sec so you see every material is different
3.) There is the max extrusion speed your nozzle/hotend/extruder/material/temperature can handle. To determine that load the filament and extrude a little. Then go into the terminal and type in (ignore anything after and including the semicolon ; as that is the comment)
G91; Select relative positioning
G1 E50 Fnnn ; where nnn is the speed in mm/min
Start nnn very low at like 120 which is 120mm/sec for flexible you might even start at 60. When you hit enter some filament will extrude. Increase nn by 60 at a time at some point the extrusion will start to look different, either shorter or inconsistent width or blotchy etc or the extruder will start to slip (click) Now you know you went too far. take the last good number - lets say it was 360. that is 360mm/min or 6mm/sec (360/60) Multiply that number by 2.4 as 1 mm of 1.75 mm dia filament has a volume of 2.4 cubic mm (mm3) so 62.4 is 14.4 - deduct 10% for safety and you get 13. For our imaginary filament the fastest extrusion speed would be 13. So now if you have a slicer like SLIC3R that does volumetric E or at least allows you to apply volumetric throttle you just enter that number and let the slicer do its thing. In MC you got to do a little more math. Take your layer width and multiply it by the layer height. Lets assume you got a .8 nozzle and work with .4 layer height .8.4 = .32 13/.32 is about 40. so the max speed for that .8 nozzle for our imaginary filament would be 40mm/sec.
Now you have those 3 numbers - pick the smallest of the 3 and no number above should be above that number and the outside perimeter should be about 80% or less. You will get that by looking at some test prints. The same for Bridging. Some filaments like HIPS you bridge at the max possible speed with slightly reduced extrusion rate some you go real slow with. Print some bridging tests to establish that number.
To clarify- I started my personal prints with flexible at that slow of speed so I can learn how the material prints. Every machine will print differently. You will definitely want to slow your speeds down across the board. Of course, your mileage may vary and some trial and error are expected. It is difficult to offer a one-size-fits-all type of setting.
Firstly, dry the material in an actively heated chamber like a PrintDry for 4 hours or so then try to attempt to start a print accordingly. That would give you the best possible results.
Sorry for late replay
I've tried to consider all your recommendations, different settings, but the result is far from good.
It starts print first layer fine with low speeds as you've suggested, but then just stops load filament.
Once reason was almost clear, because it was stuck in extruder, at the same time retraction was turned off, what makes it not clear enough, then I was forced open it to remove material manually.
But even worse, with second attempts extruder and filament was not involved when it was stuck. TPU simply stops moving along the pipe, without physical signs, the nozzle stops print material, however, in this case to unload filament I did not have to opened extruder and remove it manually, (as it was when filament was stuck in extruder, it was seen how the material wrinkled between gears), but now it was unloaded automatically successful, and I can't see any damage on the filament, which should not allow pass it through. At the same time printer works fine with NylonX, PLA, Ryno etc.
Also I've watched this lessons:
3D Printing In TPU - Tips and Tricks and TPU Material 3D Printing -
Tips and Tricks and this 3D Printing with Flexible Filaments (on stock hardware!), which describes same problem, but all I found here is almost the same, and by some reason does not helps in my particular case.
Can't figure out, what I'm doing wrong, why TPU stuck. Here is my low speed settings again, and first layer edit:
You got your temp at 190 As far as I know TPU prints at about 240ish so its supposed to get stuck as you are trying to cold extrude. Look at the filament or the web page where you bought it from and it should say
Print temp from .... to ....
or print temp ... +/- 10 degress (i.e 240 +/- 10) that means print between 230 and 250
Before you print make an extrusion test go to control, wait till it reaches that temp and then extrude 100mm or whatever you feel is sufficient, change the temp and repeat - pick the temp where its nice and consistent
I've tried it with 190, 200, 210, 220, 240, 250 but it same result. I got first 1-2 layers printed well, and then filament stops move through the nozzle.
As I've said above, once wire was deformed inside extruder between gears, and reason was more clear, but with all other following attempts, seems like something fails after extruter, because it passes or unloads filament fine, and wire is not deformed after failure. It looks like it stuck in nozzle or somewhere above between nozzle and extruder, maybe inside the tube.
I can't find any additional information for this LeoPlas TPU 1.75mm+-0.05mm, Printing temp: 190 °C Platform temp: 60 °C
Haven't tried it myself yet on the Pulse but on my CHIRON switching to a Capricorn tube made a big difference on all materials especially the more flexible ones. Its diameter is smaller and with that there is less wiggle room for the material.
I also had some problems on some low temp materials with them bunching up in the hotend if the ambient temp (in the room) was too high as the material started to soften before it got into the hotend and expanded and got stuck. So make sure the cooling of the heatsink is sufficient which is a combo between fan operation and ambient temperature
Temperature 16-18 C, but I'm not sure, what must be correct setting for fan:
@lado You might consider trying a different spool of the material if it is still giving you as many problems as it is now even after all of the settings.
I agree with @mpirringer, your temperature is very low for TPU, it should be around the 240 range.
What bed adhesion are you using?
Gluestick, Hairspray, Magigoo...?
Thank you for your feedback
I've already tried higher temperature from 190 to 240, maybe I should try higher, but if particular TPU printing temperature is 190 °C, then 250 °C must be very high, I'm not sure
For cleaning the bed I use cleaning spray without alcohol, mostly to remove leftovers easier and I use Elmer glue stick and have tried Kstick, both works, but as I've said before, it was not required for NylonX, which I have printed about 2 kg successfully small and bigger mechanical parts, and glue was never required, moreover when I've tried glue with NylonX before reset, part was not attached to bed well, and now it is vise-versa, peel off without glue and stick with glue
And I did not used glue for TPU as well, because first layer with TPU sticks very good, but filament stops to move through the tube after 1-2 layers printed, seems like between extruder and nuzzle. I don’t see this, but it seems to me that the wire is bent somewhere, maybe because the pipe is wide for it, I don’t know, how it will behave if the pipe will be narrower, because TPU and NylonX both are 1.75mm, and as far as I can see the tube is not much wider than the wire
So finally I found the reason of mysterious stuck and it is extremely simple, to such an extent that I am a little ashamed to admit
When the extruder turns reel with loading filament at a certain moment it stretches the material and, as a result, contracts in the cavity of the entrance hole of extruder and thereby gets stuck at the very beginning, before entering the gears, what explains successful unloading, when the filament stuck, and printing only 1-2 layers for small part, what is equal to point of reel turn when wire is stretched.
The solution to this problem also simple, I just unwound the wire and keep it free to not stretch and avoid this blockage, which even not looks like deformation, but as a slight thickening on tiny area after release and compression of flexible material, when the wheel turns after pulling the wire, then failure occurs
Seems like problem is solved, now I have to figure out, how can I make TPU printing a bit faster, it is too slow, I will try 30
Thank you for your attentive support