Notifications
Clear all

MK3S vs. TPU  

  RSS
mkoistinen
(@mkoistinen)
Member
MK3S vs. TPU

Is anyone having success printing SainSmart TPU with the MK3S? I was able to get a (decent) benchy, but since then, the filament gets caught up in the Bondtech gears before anything useful can be printed, requiring me to disassemble the extruder to correct again.

If you have had success, can you please share your settings for the MK3S + latest Slic3r?

Many thanks.

Posted : 19/02/2019 4:48 pm
Malibusteve
(@malibusteve)
Eminent Member
Re: MK3S vs. TPU

I've had a lot of success with my MK3. I've had the filament squeeze out a couple times but I just replaced the ptfe tube and nothing since. I am upgrading, though, so that it is easier to replace the ptfe tube. One tip I have is, slic3r always performed poorly with TPU, simplify3d, however, has been flawless when using the "pretty profiles" on github. Good luck!

Posted : 19/02/2019 6:53 pm
DaJMasta
(@dajmasta)
Trusted Member
Re: MK3S vs. TPU

Haven't moved to the 3s yet, but on my MK3 the TPU issues have been:
Too much idler pressure
Too fast print speeds

And the big one is the second. Slow down the print and you also slow down the extruder feed rate, which is what jams when the hole of the hotend doesn't keep up and you can't exert much physical force with the filament alone.

Posted : 20/02/2019 3:14 am
Sembazuru
(@sembazuru)
Prominent Member
Re: MK3S vs. TPU


Haven't moved to the 3s yet, but on my MK3 the TPU issues have been:
Too much idler pressure
Too fast print speeds

And the big one is the second. Slow down the print and you also slow down the extruder feed rate, which is what jams when the hole of the hotend doesn't keep up and you can't exert much physical force with the filament alone.

Specifically, what speeds have worked for you? (People say print slowly, but never qualify with actual speeds...)

Even better, what's a good volumetric flow rate to target, especially since the speed settings aren't in the filament settings (volumetric flow is)...

See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs

Posted : 20/02/2019 4:14 am
Nikolai
(@nikolai)
Noble Member
Re: MK3S vs. TPU


Specifically, what speeds have worked for you? (People say print slowly, but never qualify with actual speeds...)
Even better, what's a good volumetric flow rate to target, especially since the speed settings aren't in the filament settings (volumetric flow is)...

I could find my couple posts where I listed all the details, but it's easier for me type it again:
-> Set all speeds to 15mm/s
-> 235C extruder temp
-> No retractions
-> Loosen the idler pressure until it slips then fasten it ( 2-3 times )
-> 0.2 resolution
-> 1.05 multiplier
-> Make sure your Live-Z is up (~-0.1 to whatever is ideal for you)

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram

Posted : 20/02/2019 5:20 am
DaJMasta
(@dajmasta)
Trusted Member
Re: MK3S vs. TPU

A little under half 150um "optimal" print speeds, these are probably not optimal, but they've worked recently using Sunlu TPU (which is a tad hard when printed, definitely flexible but closer to hard rubber, so these probably won't work as well with softer filaments). Most recent adjustment was reducing travel move speeds which has reduced stringing somewhat (still get a good bit, but it's post-processable with hot air).

In the filament info section, use the FLEX pulldown indicator (I think this disables retractions?), max volumetric speed is (5mm^3)/s, slightly higher than manufacturer recommended temperatures and a 1.02 extrusion multiplier (1.05 is probably just fine, but the last parts I made were a pretty snug fit at base dimensions so I didn't want to push it).

My prints have been very tough, haven't been able to mangle one with regular pliers in my somewhat limited testing.

Posted : 20/02/2019 6:54 am
Sembazuru
(@sembazuru)
Prominent Member
Re: MK3S vs. TPU



Specifically, what speeds have worked for you? (People say print slowly, but never qualify with actual speeds...)
Even better, what's a good volumetric flow rate to target, especially since the speed settings aren't in the filament settings (volumetric flow is)...

I could find my couple posts where I listed all the details, but it's easier for me type it again:
-> Set all speeds to 15mm/s
-> 235C extruder temp
-> No retractions
-> Loosen the idler pressure until it slips then fasten it ( 2-3 times )
-> 0.2 resolution
-> 1.05 multiplier
-> Make sure your Live-Z is up (~-0.1 to whatever is ideal for you)

Thanx. I have a spool of NinjaFlex to experiment with.

If I do my calculation right, 15mm/s print speed with 1.05 multiplier gets me 1.4175mm^3/s. Very close to Prussa's preset for "SemiFlex or Flexfill 98A" which is 1.5mm^3/s (granted Prusa's multiplier is 1.2).

Your last point about Live-Z, do you mean raise the Live-Z that works for the rigid filaments by about 0.1 for the flex? Instead of futzing with a working Live-Z, would adjusting the Z offset in Slic3r PE printer settings do the same thing?

See my (limited) designs on:
Printables - https://www.printables.com/@Sembazuru
Thingiverse - https://www.thingiverse.com/Sembazuru/designs

Posted : 21/02/2019 7:49 am
ThaliaFP
(@thaliafp)
Eminent Member
Re: MK3S vs. TPU


I could find my couple posts where I listed all the details, but it's easier for me type it again:
-> Set all speeds to 15mm/s
-> 235C extruder temp
-> No retractions
-> Loosen the idler pressure until it slips then fasten it ( 2-3 times )
-> 0.2 resolution
-> 1.05 multiplier
-> Make sure your Live-Z is up (~-0.1 to whatever is ideal for you)

Thank you very much! It works like a charm for me. Idk what you mean with the live-Z up, but with no change here it worked fine!

My designs in Thingiverse
Posted : 22/03/2019 6:00 pm
Nikolai
(@nikolai)
Noble Member
Re: MK3S vs. TPU

I'm glad it worked for you!
By raising Live-z I meant to bring your nozzle up for the first layer. The first layer shouldn't be squished like for ABS and sometimes the perfect PLA first layer is too close for TPU. You might build too much pressure in the nozzle during the first layer and then it tends to fail on the second,third.
Based on the size of the first layer, it's more or less an issue.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram

Posted : 22/03/2019 6:10 pm
levi.k
(@levi-k)
New Member
Re: MK3S vs. TPU

Sorry to bug everyone here but has anyone else noticed a difference with the new MK3 firmware 3.5.2?
I was previously able to print a few parts with NinjaFlex if I was careful and helped it load a bit but with the new firmware it seems to do a more aggressive purge at the start of the print that jams the NinjaFlex filament every single time now, I have found some success by pausing the print before it starts and then reloading the filament but it seems to be under-extruding when I do this and I can't figure out why.

Am I missing a setting that can slow down the purge or even shut if off for flexible prints?

Posted : 24/03/2019 6:36 pm
George
(@george-8)
Eminent Member
RE: MK3S vs. TPU

Hi, I'm struggling with Sunlu TPU....

I took the default settings for FLEX 98, then I modified with the setting you showed in this post and I slightly tweaked it.... since I was having the filament getting tangled on the bowden gears...

I increased the temperature to 250°C and I put the multiplier at 1.00, all speeds at 15 mm/s

Here attached a Slic3r profile (to whom it may be interested) 

MK3 updated to MK3S / mainly textured steel sheet (also have a smooth one) / PLA and PETG

Posted : 17/07/2020 4:53 pm
George
(@george-8)
Eminent Member
RE: MK3S vs. TPU

Hi again, 

After a good print, I thought I had the right settings, but I launched the same GCode 5 more times with no success.... the filament gets tangled on the bowden gears... I tried different load on the spring screw, same results. 

The printer works for about 10 minutes, and very often on the half of the second layer it gets jammed. (basically is a cylinder 50mm diameter at 100% infill) 

Any help? 

MK3 updated to MK3S / mainly textured steel sheet (also have a smooth one) / PLA and PETG

Posted : 17/07/2020 8:03 pm
George
(@george-8)
Eminent Member
RE: MK3S vs. TPU

a little update, it might help others. I believe 2 things drastically improved my prints:

1) the screw for the bowden gears: I loose it 3/4 of a turn I put a sticker and made marks with fine permanent marker...

2) I put back the original Prusa spool holder I believe this is the spool holder with the less friction on it... I guess that my main problem was the filament being pulled "hard" therefore becoming thinner, thus finding its way out of the PTFE tube..... 

 

I hope this helps some people.

 

MK3 updated to MK3S / mainly textured steel sheet (also have a smooth one) / PLA and PETG

Posted : 30/09/2020 2:58 pm
Share: