TPU 95A Benchy Overhang Issues

Bambu Lab X1 Series Troubleshooting
1

Hello All,

I am noticing when trying to print the Benchy I am getting some overhand issues with the print.

You can see in the front of the print the layer lines seem to be sagging downwards.

Using 0.4 nozzle and 0.2 layer height. Using 30 mm/s print speed.

Any suggestions would be appreciated!

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2

what is the temp might be too hot

3

Here are the settings for the filament:

Filament

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Cooling

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4

try putting the fan to 200%

5

Lowering the print speed gave some noticeable improvements. I’m going to make another run with this speed settings and try and few more changes.

I don’t see how you can set a fan speed above 100% @sharcrypto?
100% is the max and 0% is the min.

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6

put the aux fan on 100 like i did

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7

Hi. I tried printing with overture TPU and have a very similar result. The front-wall bends inwards and deforms. Reducing the print speed helped a bit. Did you solve the problem?

8

I had similar issues before! Printed using Bambu TPU 95A-HF in X1C.

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I actually figured out it was not a cooling issue. You can see that your overhangs on the port and cabin are actually good. And when I reduced extrusion temperatures it actually became worse.

From my testing, this defect occurs where extrusion rate changes quickly. I think the elasticity/viscosity of the TPU plays a role.

I found what helped was the following:

  1. Reducing print speeds and accelerations. In particular for outer walls.
  2. Increasing nozzle temperature.
  3. Adjusting PA value.
  4. Extrusion rate smoothing.

In a similar vein, stringing is better with slower retraction/de-retraction speeds.

You will have to do your own testing but I found making following changes impactful:

  • Extrusion temperature from default 230 → 250ºC
  • Outer wall speed at 50 mm/s with 2000 mm/s^2 acceleration
  • PA = 0.068
  • Extrusion rate smoothing 300 mm^3/s^2
  • Reduce retraction speed & de-retraction speed from default 30 mm/s to 10 mm/s
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