RE: Printing TPU on the MK4
Thanks for taking a look, I really appreciate it. I'll try your suggestions and see how it goes.
Thanks again.
RE: Printing TPU on the MK4
Sure, let us know how it goes. TPU is annoying until you get a feel for it. going from mk3 to mk4 and now the xl too, I've had to relearn it.
Thanks for taking a look, I really appreciate it. I'll try your suggestions and see how it goes.
Thanks again.
RE: Printing TPU on the MK4
ssill2, thanks again for the help. I increased the temperature and decreased the mvs as suggested but the extruder still began clicking on the "bridging infill layer". As the failure is almost always on this layer I decided to make the print solid and increased the top and bottom layers accordingly (I also bumped the temperature up to 230C). Success, a completed key chain with color change and no extruder clicking!
What I don't understand is why a bridging infill layer was causing the problem when I had the speeds for all print moves set to approximately the same 30mm/s. I'm sure I'm missing something but for this particular model a solid print works fine. If you have any thoughts on this though I would appreciate your input.
I'm going to try and decrease the temperature as 230C gave quite a lot of stringing.
RE: Printing TPU on the MK4
I'm not sure why you'd get the clicking on the bridging infill, I've not seen this. I always try to adjust the speed with the mvs, and not via the individual speed parameters. I'm used to printing with ninjaflex(85A) and 30mms/sec seems entirely too fast for tpu. But every variety of tpu is different, which is why it's so frustrating. The string should definitely reduce with lower temp, you can try going back down by 5 deg increments and if you get the clicking again go up in 2 deg increments. It's important to try not to change too many settings at a time though. As I think I've mentioned on this post, if you're going to be printing a lot of something I'd find one or two brands/types of tpu and get them dialed in and then stick with those. For me it's Sainsmart and ninjaflex.
ssill2, thanks again for the help. I increased the temperature and decreased the mvs as suggested but the extruder still began clicking on the "bridging infill layer". As the failure is almost always on this layer I decided to make the print solid and increased the top and bottom layers accordingly (I also bumped the temperature up to 230C). Success, a completed key chain with color change and no extruder clicking!
What I don't understand is why a bridging infill layer was causing the problem when I had the speeds for all print moves set to approximately the same 30mm/s. I'm sure I'm missing something but for this particular model a solid print works fine. If you have any thoughts on this though I would appreciate your input.
I'm going to try and decrease the temperature as 230C gave quite a lot of stringing.
RE: Printing TPU on the MK4
If one enables display of the MVS in the slicer, it is possible to see the parts of the model that have the highest MVS. If that's in the bridging area - then the obvious thing is to reduce MVS. Making one change, (MVS) is a whole lot better than making and keeping track of dozens of tweaks!
For me, the only think that effectively eliminate the clicking was to really loosen the tension. Make it so loose that when there's no filament and the arm is closed, the springs rattle. When there is filament in place there will be slight tension. If it still clicks, loosen even further. I didn't believe it would work, but it does.
It doesn't take much tension to feed TPU. We are talking really loose, just the smallest amount of tension. The assembly instructions tell you to set to a very high tension, and this will fail on TPU!
If later you print with IS and other filaments you may hear rattling, just slightly increase tension a tiny, tiny bit. I can say PETG feeds fine even with this slight tension.
For Overture TPU I was able to get a print using MVS=3.5. But the print quality was not the greatest, there was too much coarse stringing. I got significantly better print quality at MVS=5 using Sainsmart GT-3 high speed TPU and drying my filament at 65C. Prints improved a lot with the 65C drying. I found 55C drying was insufficient to drive out the moisture in TPU.
RE: Printing TPU on the MK4
Thanks to you both for the suggestions, I'll keep tuning.
I did change all the individual speeds initially based on the recommendation on the spool (20-40 mm/s) and then I changed the mvs based on this thread so now I have both changes in place. Maybe I should go back to the Amazon basics profile and only change the mvs?
Just checked the mvs in the slicer and indeed the bridging infill layer is the highest mvs layer within the print. Most layers show around 2.5 and that one is 3.7 (tough to tell from the colors though). Will definitely change that and check again.
RE: Printing TPU on the MK4
Welcome to printing tpu lol. You hopefully see now why I hate it lol. Thankfully you're not printing on an XL and have to worry about tool changes too!
Thanks to you both for the suggestions, I'll keep tuning.
I did change all the individual speeds initially based on the recommendation on the spool (20-40 mm/s) and then I changed the mvs based on this thread so now I have both changes in place. Maybe I should go back to the Amazon basics profile and only change the mvs?
Just checked the mvs in the slicer and indeed the bridging infill layer is the highest mvs layer within the print. Most layers show around 2.5 and that one is 3.7 (tough to tell from the colors though). Will definitely change that and check again.
RE: Printing TPU on the MK4
Try changing only one thing at a time. Makes it easier to figure things out. Change MVS from 3.5 to 3.0, or even 2.5 and see what happens. If it works then you could tweak the bridging infill parameters.
Thanks to you both for the suggestions, I'll keep tuning.
I did change all the individual speeds initially based on the recommendation on the spool (20-40 mm/s) and then I changed the mvs based on this thread so now I have both changes in place. Maybe I should go back to the Amazon basics profile and only change the mvs?
Just checked the mvs in the slicer and indeed the bridging infill layer is the highest mvs layer within the print. Most layers show around 2.5 and that one is 3.7 (tough to tell from the colors though). Will definitely change that and check again.
RE:
This 100%. Be prepared to burn some filament initially to get things dialed in.
Try changing only one thing at a time. Makes it easier to figure things out. Change MVS from 3.5 to 3.0, or even 2.5 and see what happens. If it works then you could tweak the bridging infill parameters.
Thanks to you both for the suggestions, I'll keep tuning.
I did change all the individual speeds initially based on the recommendation on the spool (20-40 mm/s) and then I changed the mvs based on this thread so now I have both changes in place. Maybe I should go back to the Amazon basics profile and only change the mvs?
Just checked the mvs in the slicer and indeed the bridging infill layer is the highest mvs layer within the print. Most layers show around 2.5 and that one is 3.7 (tough to tell from the colors though). Will definitely change that and check again.
RE: Printing TPU on the MK4
Thank you all for great advice. With very similar settings I managed to print Filatech`s FilaFlexible 40 (Shore D40) on Prusa MK4 feeding via short PTFE. I first pushed filament into nextruder and only then inserted PTFE tube.
I cranked temperature to 235, maybe that's why I had some stringing, but it was easy to remove. Detail was also acceptable.
RE: Printing TPU on the MK4
Question for you guys who upgraded your MK3S printers to MK4. If you could go back to an MK3S for printing TPU would you do it if you could have more than one printer?
I have a pair of MK3S+’s that I put in enclosures for printing ASA, PC Blend, TPU, etc. I upgraded them with Bondtech LGX extruders and Mosquito hotends to make printing TPU less painful and nozzle changes much easier.
I’m now trying to decide if I should sell these and then eventually get two MK4’s, but after reading this 10 page thread I’m wondering if perhaps I should upgrade to MK3.5 to get the IS speed bump and stick with what I got.
So, based on your experience with both printers, given my situation would you upgrade or sell for the MK4’s?
RE: Printing TPU on the MK4
I wouldn't. The MK4 is a much better printer. However, I hadn't invested in non-stock extruders or hot ends.
I upgraded my MK3S+ to the MK4 via the upgrade kit. Really the only thing that was annoying for me on the MK4 was the extruder jam/clicking for TPU. Once I was alerted to needing to change the tension, jams went away. The MK4 printed PETG flawlessly after the kit upgrade. And only the slightest wispy stringing with TPU after extruder tension adjustment.
RE: Printing TPU on the MK4
Yeah, I like the MK4 better now that things are dialed in. I love not having to remember steel sheet profiles etc. I'm not even using the IS profiles for the printers.
I wouldn't. The MK4 is a much better printer. However, I hadn't invested in non-stock extruders or hot ends.
I upgraded my MK3S+ to the MK4 via the upgrade kit. Really the only thing that was annoying for me on the MK4 was the extruder jam/clicking for TPU. Once I was alerted to needing to change the tension, jams went away. The MK4 printed PETG flawlessly after the kit upgrade. And only the slightest wispy stringing with TPU after extruder tension adjustment.
RE: Printing TPU on the MK4
Yeah I feel the same way as both of you. If I did not already invest in the Bondtech and Mosquito I would just sell and get new MK4’s. I really like the ease of my XL and every time I print with it I am ready to drop down on a MK4.
I am just a bit torn between the two options, especially since I’m pretty sure I won’t get much at all for what I already have. Not the end of the world but is what’s giving me pause to consider the MK3.5 upgrade.
Thanks for your thoughts on the matter, now just have to make a decision.
Yeah, I like the MK4 better now that things are dialed in. I love not having to remember steel sheet profiles etc. I'm not even using the IS profiles for the printers.
I wouldn't. The MK4 is a much better printer. However, I hadn't invested in non-stock extruders or hot ends.
I upgraded my MK3S+ to the MK4 via the upgrade kit. Really the only thing that was annoying for me on the MK4 was the extruder jam/clicking for TPU. Once I was alerted to needing to change the tension, jams went away. The MK4 printed PETG flawlessly after the kit upgrade. And only the slightest wispy stringing with TPU after extruder tension adjustment.
RE: Printing TPU on the MK4
Ninjatek Edge on my MK4 with .4 nozzle.
Trying to track down under extrusion.
When extruding, with the screws are their normal factory depth, I can pull the filament right out, like the gear isn't even engaged.
I have speeds at 25mm/s for most but infill and solid are at 50mm/s, mvs is set at 2, extrusion multiplier is set at 1.3. Printing at 245c
I have similar issues with Cheetah, but not as pronounced
RE: Printing TPU on the MK4
I do:
1.12 Extrusion multiplier
238C
1.2 MVS
1.5 retraction length
20 retraction speed
20 detraction speed
it's slow but with the softer filaments slow and steady wins the race.
It's been a while since I did ninjaflex on the MK4, I mostly do it on XL which usually has similar settings.
I just checked, yes, my xl and mk4 settings are same.
RE: Printing TPU on the MK4
what about the tension? When it's printing, can you just pull the filament out? Seems like there should be resistance from the extruder gears
RE: Printing TPU on the MK4
The tension should be as light as you can get it and have it feed, but not jam. On my MK4, this is very, very light, the springs are just barely compressed. Less compression and the springs would rattle. I wouldn't be surprised if you could pull the filament more than the feeder pulls, but I haven't tried that. Too high a tension, at least for me, would result in jams, especially in parts of the model that needed higher MVS. But I see your MVS override is very low, so unless your filament is super soft, you should be ok. HTH.