Printing TPU with A250 (or any SM 2.0)

Snapmaker 2.0 (3-in-1)
42

Finally successful with TPU!

IMG_4907
IMG_49072016×1512 2.38 MB

Thank you so much for the adapter idea chazr33gtr!

I kept having problems getting the adapters to print and when I did they were so fragile I ended up breaking them. Then it occurred to me that it is a CNC machine. I created a new version of the adapter in Fusion and then milled it out of a block of teflon I happened to have (my grandfather worked in aerospace as a material and process engineer). Had to do a little whittling and filing to take care of some areas my bit was too big too reach.
No more backup loops!
Printing at 18mm/s to start. Now I’ll have to start playing around and see how fast I can push it. I printed with a brim for the cube. Trying a skirt now. Needed the first half of the loop to be flowing properly.
The best thing about the adapter is not having to take anything apart to add it. Easy to remove (not sure I’ll need to) for other filaments.
-Steve

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Share the file for cnc please!

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Here you go. Fusion 360 files had to be zipped.

Milled profile first. Block I had was 15mm so I just used utility knife to separate from base. Then rotated piece 90 deg to cut the hole/slot using a wooden vise to hold it. Made slot slightly undersized so I didn’t have to be perfect centering it and could enlarge by hand. When you run boundary it shows you pretty well if you’re lined up correctly.
Flattened top and bottom tabs and squared up inside angle with a file.
Door should close with some pressure. I couldn’t install it on the machine. Had to lay head on it’s back to keep it from sliding out.
-S

Archive.zip (374.3 KB) SM2_adapter hole_single pass.cnc (2.8 KB) SM2_TPU adapter single pass 3_175mm.cnc (1.3 MB) Snapmaker 2 TPU adapter.stl (51.0 KB)

45

Finally started working with TPU today and glad i checked back here first for the adapter! I printed that first (thanks @chazr33gtr !!) before swapping to TPU, then just tried higher temp and slower output (to lower the pressure) and that didn’t quite seem to do it. It still output SOME filament, but it wasn’t consistent enough. Without being able to watch the inside of the box, I suspect that the filament would get bunched, slip off, release, and slide back on. But with the adapter, no problem!

I did make an addition to it so I could print the single piece. I hate doing multiple pieces when I don’t have to if I can just add on a support or something that I can remove later. I also hate the generated supports and try to add my own. Attached is a breakaway tab so you can print the single piece easier that you can bend or cut off fairly easy (it just has 1-2 layers of attachment to the model, which should be plenty to keep the surface area up to the base plate).

Since I use Simplify3D, i also tend to print with Single Extrusion enabled and allow for single extruded walls (which is what it did for the side tab and the single small vertical).

snapmaker_flex_feed_adapter_one_piece_w_breakaway.stl (29.9 KB)

Currently printing an ear saver (slated to print a bunch of these for local game store with their logo, and a bunch more for cousin’s group of teachers!). printing at 220 (high end of filament temp) @ 20mm/s all the way around (per the video, but i would bet now with the adapter it could go higher).

UPDATE: Yup, turned out pretty great actually.

IMG_E1490
IMG_E14903622×1177 1.98 MB

For those using Simplify3D, here is my TPU profile (i only used 50% infill for this model, but there was barely any infill anyway, so nearly 100%).

Snapmaker 2.0 - Med - TPU.fff (11.9 KB)

I still need some work on the model itself, but mostly the wording since that was pretty tiny to begin with. That doesn’t really have anything to do with the TPU you as it printed like any other once I got the adapter in there.

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Hadn’t thought of doing it that way. That would’ve solved the problems I was having printing the single piece. Always more than one way to do something. It’s always fun to see other’s solutions.

It’s so nice to be able to print flexible filament. Opens up so many more things to print.
I dropped the controller for my A350 a couple times and was worried about breaking it. Designed a simple bumper case to help protect it.

IMG_4909 2
IMG_4909 23024×4032 2.46 MB
IMG_4910 2
IMG_4910 23024×4032 2.2 MB

-S

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Hi all, I’m trying to print TPU with my A250 for 1st time.
As this thread mentioned about, the max speed should set in 20mm/s. (or lower)

Just wondering, which speed should I set in Luban ?
圖片

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all of them except the travel speeds :slight_smile:

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With adapter this is what worked for me (with Filamentone Pro Select TPU):

Screen Shot 2020-08-17 at 2.08.10 PM
Screen Shot 2020-08-17 at 2.08.10 PM732×1570 124 KB

Haven’t had a chance to try how much I can speed things up. Only printed smaller items so far that weren’t going to take that long anyway.
-S

50

I got very weird print result with TPU…
Here’s my 3D object, clearly, text and plate ware there : (And merged in 1 module)
Plate was 2 mm height, and text was 1mm.

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01751×418 76.8 KB

Also in Luban :
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Setting was followed with @sdj544 's hint, but the result …

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031024×512 174 KB

My A250 shows print progress was 100% complete, but there is no text…
and there is no failed filament when print finished, so it seems not just print fail. (Both are just 2mm height)
How is it happening ?

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It may caused by Luban’s slicing … maybe a bug ?

I just re-create whole stamp to 140 x 90 mm, so that I can make text larger.
When Luban slice finished, I swap Outer Wall on/off in preview, here’s result :
Outer Wall ON

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Outer Wall OFF, some text are totally disappeared, no Inner Wall and Skin

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Looks like it stopped extruding by the time it got to top layers and letters. Nozzle clog? Do you have it set to print at same temperature whole time? Might try increasing temp 5 or 10 degrees.

Your layers don’t look great to start with. TPU needs very little offset. Unlike PETG it needs to be squished.

You can increase height of top layer in Luban to make sure it considers both letters and flat top surface to be top layer.

Sometimes prints just fail and you try them a second time and they’re fine.
-S

53

Nozzle isn’t clog, and it’s temperature was start with 205°c, and down to 200°c when print final layer. (in that part, I just followed default PLA settings)

The Z-axis I had set it about -0.1 ~ -0.3mm after auto leveling, this is just for print with TPU.

I had rebuild 3D model, increase letter height to 2mm(it was 1mm in my original design), sliced and printed, same result, still no lock.

For a reference, I printed them with PLA(using Luban’s default PLA fast print), here’s result :

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圖片1280×640 160 KB

So maybe something wrong with my TPU setting … ?

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The nozzle doesnt have to have clogged to stop extruding when using TPU. Likely you are trying to print at too high a speed and this causes the TPU to bunch up where the extruder gear contacts the filament.

try slowing your print speed down

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Print speed was followed this thread, I tried 20mm/s and 18mm/s, but no lock. :slightly_frowning_face:

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Have you tried printing and applying the adaptor shared earlier in this thread?

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Nozzle isn’t clog, and it’s temperature was start with 205°c, and down to 200°c when print final layer. (in that part, I just followed default PLA settings)<

You can’t just use PLA settings for TPU. (That’s the whole point of this thread)
First of all, most TPU needs higher nozzle settings (220-250). Your supplier will have recommendations on product page and probably on the reel. Mine needs 235. So it was struggling to extrude to start with at 205 and then stopped when it went to 200.
Is retraction off? TPU needs no retraction.
Print speeds need to be much slower than PLA
-S

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Retraction is OFF, and speed was set to 18mm/s to 20mm/s, as this thread mentioned about. No luck.

I’ll try higher nozzle temperature soon, just wondering why my plate been printed well, but not even single letter printed …

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PLA & TPU - They’re two completely different kinds of filament with different temperature requirements and different flow rates depending on those temperatures. If your temperature isn’t high enough to melt the filament it’s not going to come out of the nozzle. (or too high and it may just drip out).

Even within the same types of filament you’ll have different settings depending on the manufacturer and color. White tends to need slightly higher temp than black.

-S

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Finally done with TPU, took me 72 hours …
Thanks for all your suggestion, it helps a lot :slight_smile:

Here’s my TPU print setting :

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The result (black part) :

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@RossCHT sweet you got it to print! But again, it’s NOT just the settings in Luban. The other things mentioned above are the inserts printed that go inside the 3D module that help hold the TPU filament in place.

If it’s not clear why: the door to the mechanism for the 3D module has a wheel, which has a spring pressing that wheel against the filament, attempting to “hold it straight” so that the feeder can apply enough force to push filament through the nozzle as it melts. Since the pressure travels down the length of the filament, it’s important for it to stay “straight”. the small adapter (models linked, and I added the same model with a different base) is nearly a “requirement” for this!

The second I put it in, I had immediate success in printing MANY things with TPU. I received on Friday a new nozzle that I will be trying soon that should help further (i will post results here) in reducing pressure and increasing the life of the nozzle (since TPU is quite ‘sticky’). Currently my heated bed is not heating (i have to check the connections, and i have a few other things to do, so i’ll be taking pretty much everything apart tomorrow).