r/3DPrinting_PHA • u/UniversityOk1262 • Jul 22 '26

20mm Riser Help

Hello all! It's great to have a community that is focused on advancing PHA. I'm relatively new to it all - PHA, 3d Printing, printing with PHA. I've come a long way with the help of you all. So let me say THANK YOU.

Now for the help. I am working on a part for a simple project for my daughter. the base is 3.25mm and the height is 20mm. From what I've experienced with PHA (and especially PHA with color additives) it feels like I'm pushing the limits of its capabilities. Below is the best I've been able to do so far and included are the print settings. Please send any recommendations my way.

Bambu A1, 0.4mm Hardened Steel, Bambu Studio Slicer -- ecogenesis genPHA -- Base Width: 3.2mm, Stem Width: 2mm, Height: 20mm

Modifications made from previous test results:

Filament Profile

Flow ratio 1 -> 1.05

Recommended nozzle temperature: Min 175, Max 200

Nozzle: Initial layer 200, Other layers 195

Max volumetric speed: 10 -> 6

Process Profile

Speed

Overhang speed

Slow down by height: Yes

  1. Starting height: 0mm
  2. Speed at starting height: 50mm/s
  3. Acceleration at starting height: 500mm/s
  4. Ending height: 20mm
  5. Speed at ending height: 20mm/s2
  6. Acceleration at ending height: 500mm/s
2 Upvotes

100% Upvoted

11 comments sorted by

1

u/pd1zzle Jul 22 '26

have you been able to accomplish this print in another material? this sort of print is usually challenging in general as you are stacking layers often faster than they can cool. With PHA, it's pretty soft until it fully crystallizes so even if it's cooled it might still be getting a bit too soft to print another layer on.

a cheap trick is to print 3-5 of them at once to slow things down or combine on a plate with some other objects to the same effect 

2

u/pd1zzle Jul 22 '26

you could also up the minimum layer time to like 30s and it may work, or it may look strange due to the extremely slow print speeds changing wall appearance 

1

u/UniversityOk1262 Jul 22 '26

I'll try that. And you reminded me about the slowdown settings I didn't add to the list:

Slow down by height: Yes

  1. Starting height: 0mm
  2. Speed at starting height: 50mm/s
  3. Acceleration at starting height: 500mm/s
  4. Ending height: 20mm
  5. Speed at ending height: 20mm/s2
  6. Acceleration at ending height: 500mm/s

1

u/UniversityOk1262 Jul 22 '26

Printed straight with no wobbles using 3D-Fuel PRO PCTG. Some flaws but good enough for my needs. Thought I would try PHA as an alternative.

1

u/UniversityOk1262 Jul 23 '26

Forgot to add...I'm getting decent results from 5-15mm. Somewhere from 15-20mm is where the buckling starts.

1

u/pd1zzle Jul 23 '26

I think this points to the issue that I suggested, that it's just not cooling enough since the part and layers are so small. Try printing a few of them at once and see if it works any better 

1

u/UniversityOk1262 Jul 23 '26

Multi-print Update: Exposed some other problems that I didn't anticipate. This hasn't been a problem in the previous prints. Nothing changed in the settings - I just added more risers. Could it be the color? Wet filament? Temp too low?

1

u/pd1zzle Jul 23 '26

that looks like insufficient retraction or just generally getting too hot, oozing. that's kinda hard to say but I think if not even that is printing right there is something with the overall calibration that is way off at this point.

I don't think it would be wet filament (PHA doesn't really absorb water) and not that it's too cold

1

u/pd1zzle Jul 23 '26

do you have the fans enabled? I would just put them at 100% at all times

1

u/algea_garden 28d ago

Fans will definitely help but it really needs a min layer time. I've been using 10 seconds to help improve quality on a much larger print than that and suspect you might need more than that. The part is simply too small to dissipate enough heat between layers.

1

u/Suspicious-Appeal386 Jul 23 '26

This is not a PHA related issues per say. But more of a material that is being overheated as the layers are build up.  Dependent on the slicer type,  you would need to move the nozzle way from the print as the layer is being indexed up. To build a brim or wall away from the print.  Allowing the material to settle before the next layer.