Printing TPU

[mvdveer]

Well in printing the parts for the Turtle Box - there are two components that needed printing in TPU. I have previously successfully printed TPU on the Trident 300 with CW2. However that has been upgraded to a Galileo extruder as has the other printers. Just could not get TPU to print - got snagged in the extruder. Did a lot of research and some even suggested drilling out the portion between the feeder gear and fitting a 4mm teflon tube there (was in relation to on orbiter extruder) - did not think it was an easy option. And I needed something to work on any printer.

After a lot of reading, fiddling with settings and experimentation, I have found a solution that works for me and is replicated across all my printers. No drilling or alteration to toolhead required.

I thought I would share if it may be helpful to you. Please remember this has worked for me and is NOT a recipe for guaranteed success.

1. Setup:

• Dry out the filament - no option here. Either in a dry box or the oven at 60 degrees for 4 hours at least.
• Have the filament spool rotating freely - and I mean freely - you do not want tension on the filament - it stretches.
• Remove your Bowden tube from the toolhead and feed the TPU directly into the extruder - minimises friction this way.
• Loosen the tension spring on the guilder - you don't want to squash the filament in the extruder.

2. Slicer Setup:

• Use a slow print speed - I use 35mm/s
• Have the print speed uniform across all aspects (infill, walls, bridges, etc)
• Disable retraction
• Avoid crossing perimeters to decrease stringing
• Set extruder temp to around 240 - don't want it too hot as stringing will increase. Bed temp = 60

 

 

 

 

3. First Layer Squish:  

• Increase the Z-Offset to have LESS squish. (I had a lot of trouble figuring this one out but in the end - it was the most crucial part and it was not mentioned anywhere in my research). I had to adjust my Z-Offset by 0.15 in order to get good flow. If you have a PETG setting, then I guess it would be similar. Having the nozzle too close to the build plate obstructs flow and because TPU is soft, it "bundles up" in-between the extruder gears.

4. Other:

• Non - heated chamber. 
• Preferable print on a smooth plate - much easier to remove the print.
• This is not a "click and forget" print - you need to watch the first layer go down to ensure that the filament is flowing and you don't have too much squish.
• Print one component at a time - this will avoid "blobs" on the part and stringing between multiple components.

Hope this will help someone wanting to venture into the arena of TPU printing. 

Happy printing TPU!

[SuperBoppy]

Thanks for sharing your experience with some solutions that help.

I have a 4 year old Voron 2.4 with Afterburner and Dragon all metal hot end. Could never successfully print TPU. The first layer or two would print well, then the flow would diminish after that until almost nothing was coming out of the nozzle.

I have an 8 year old TEVO Tarantula. With the original hot end (PTFE), it printed TPU well. I upgraded the hot end to a V6 all metal and I had the same exact problems printing TPU as I had with the Voron.  I replaced the metal heat break tube in the V6 with a PTFE lined one, and the V6 printed TPU just fine. It appears that TPU, as it crosses through the metal heat break and into the hot zone before the nozzle, wants to stick to the metal as it transitions from solid to molten. At least that’s my theory .

The idea to use the PTFE-lined heat break to print TPU came from someone on the Voron Discord site.

So, when I need to print TPU, I do it on the Tarantula.

[mvdveer]

2 hours ago, SuperBoppy said:

At least that’s my theory .

And a valid one - makes sense. Maybe having a dedicated printer for TPU is a good idea, Just don't use it that much to warrant that. Suppose I can modify one of the V0's for that purpose.

[Methos]

I have just printed my Box Turtle TPU parts; I'm using a Rapido High Flow and a VZ Hextrudort in a Stealthburner body. 

I loaded a default TPU filament profile for the Voron, and as I always print volumetric, I set the following:

• reduced the max 6mm3/s
• Disable retraction in the filament override
• Set 240 first layer and all others to 235
• Set Avoid crossing perimeters

The result of this is that the speed is reduced, but I do not have to change any other speed or acceleration details

[Penatr8tor]

8 hours ago, mvdveer said:

And a valid one - makes sense. Maybe having a dedicated printer for TPU is a good idea, Just don't use it that much to warrant that. Suppose I can modify one of the V0's for that purpose.

V-Minion would be a perfect TPU printer.

As long as you don't need to print anything over 180mmx180mm

[nvanstaden]

i print functional seals for gear drives in TPU its about 90% of my printing.

they are all 28mm thick and range from 4" to 7" in diameter with concentric rings to act as a labyrinth for grease.

i can second everything mvdveer said, however i print on sailfins instead.

these need to be printed in under 2.5 hours to make it so that if something happens i can reprint a seal the same day.

on a regular sliced profile these parts take 12-17 hours.

i have managed to bring that down to sub 2.5 hours.

o.8mm cht nozzle on a high flow dragon, but the filament is the most important part.

i use overture high speed TPU.

for smaller parts i agree that a non heated chamber is good but for bigger ones i have found that it shrinks too much and either lifts the plate from the bed or comes loose.

all in all about a 95% success. only thing that still remamins to be solved is the bulging z seams. no amount of pa can get it down since i switched to klipper. in all honesty marlin x cura did a better job on the seams.

[claudermilk]

Good tips there! I've managed to print a couple of TPU parts, but they were ugly if functional. There's some settings in there that make sense & I will have to try next time I tackle that hellish material.

[SuperBoppy]

The only brand I have used is Sainsmart 95A TPU. Have had good results as long as I use a PTFE heat break.

I attached a photo of a trailer safety chain holder I made out of it.

Edited December 2, 2024 by SuperBoppy

[Methos]

11 hours ago, Methos said:

I have just printed my Box Turtle TPU parts; I'm using a Rapido High Flow and a VZ Hextrudort in a Stealthburner body. 

I loaded a default TPU filament profile for the Voron, and as I always print volumetric, I set the following:

• reduced the max 6mm3/s
• Disable retraction in the filament override
• Set 240 first layer and all others to 235
• Set Avoid crossing perimeters

The result of this is that the speed is reduced, but I do not have to change any other speed or acceleration details

I forgot to mention I'm using a 0.5 tungsten carbide nozzle.

[Penatr8tor]

47 minutes ago, Methos said:

I forgot to mention I'm using a 0.5 tungsten carbide nozzle.

Where did you find a .5mm nozzle?

I've been trying on and off to pick up a 5.mm bozzle nozzle but have not been able to catch anyone that has one in stock.

[therm_virtual0y]

22 hours ago, mvdveer said:

And a valid one - makes sense. Maybe having a dedicated printer for TPU is a good idea, Just don't use it that much to warrant that. Suppose I can modify one of the V0's for that purpose.

I use my old trusty Ender3 for TPU and it does great.  Can’t have too much squish like you said and I do have to watch the first layer at least.  The only flexible material I have not been successful with so far, is Taulmans  PCTPE filament.  It swells in the heatbreak and jambs every time no matter what I tried.  I’ll try the setting you recommend and see if that helps.  Thanks 

[Methos]

10 hours ago, Penatr8tor said:

Where did you find a .5mm nozzle?

I've been trying on and off to pick up a 5.mm bozzle nozzle but have not been able to catch anyone that has one in stock.

I've had them for well over 2 years; one is a form of bozzle nozzle that I got from a company in Perth, Australia and the other Phaetus.

[mvdveer]

12 hours ago, Penatr8tor said:

Where did you find a .5mm nozzle?

Seems the bozzle nozzles will be coming back in stock mid December. Local at Uniqueprints, Australia. Can get the nickel plated 0.5 locally from Rising Sun FPV

Else the bozzle nozzle will be available mid December in Europe at 3do.dk , in Canada at Northprint3d or at Fabreeko in the USA. Maybe just add yourself to the mailing list for availability and order then. 

[Penatr8tor]

@mvdveer Thanks,

Fabreeko is probably who I'll go with, had good service from them in the past. 

[sixfoxs]

Thank you for your share