Issue With Print Lifting From Supports on One Side with PETG
Hi all,
I am new to 3D printing, and after having some fun with PLA prints, I finally decided to try PETG and got slightly defeated 🙂 so I decided to ask for some advice.
I am printing a small model with a slight slope that is placed on supports, and the issue I am having is that no matter what I try (with my limited knowledge), it always lifts from the supports on one side — always the same one. It does not matter how I rotate the model on the build plate. I thought maybe uneven cooling was causing it, and rotating the model would either fix it or at least move the issue to the other side.
The lifted part is circled in red in the pictures.
I am printing on a Core ONE with a 0.4 nozzle using Prusament PETG.
I tried lowering the extrusion multiplier first to 0.95 and later to 0.93. At the beginning, the prints had small blobs on the sides, which this adjustment got rid of.
I also tested different settings and configurations:
I tried layer heights of 0.15 and 0.20, as well as variable layer height.
Nozzle temperatures: 255, 250, 245, 240
Bed temperatures: 80, 85, 90, 95
Fan speed minimum: 10%, 20%, 30%
Fan speed maximum: 25% and 30%
Support styles: Grid and Organic
Top contact Z distance: 0.1, 0.15, 0.2
Interface pattern: Rectilinear
I also tried printing with the top cover closed, open, and completely removed.
Depending on the settings, I get either a matte or shiny finish and more, less or no stringing, which I understand. However, regardless of the settings or the model rotation on the plate, I always get the same part of the model lifting from the supports.
I would greatly appreciate any help or advice. If anyone wants additional pictures or the file itself, I can upload them.
It's hard to be sure from your pictures but I suspect the problem lies with the geometry of the part. For a more precise reply save your project as a .3mf file
Files > Save Project as
Zip the .3mf and post it here. It will contain both your part and your settings for us to diagnose.
However:
When an overhang rises at a shallow angle - whether supported or not - thermal contraction dominates.
Each new overhang perimeter is supported only on one side and adheres to nothing beneath so when the layer is complete and begins to cool there is nothing to resist the thermal contraction and it warps to curl upwards, the next layer repeats and reinforces the effect and eventually the growing overhang visibly lifts - sometimes this is enough to interfere with the movements of the print head and the print fails with a head crash. Unfortunately the layers have to cool so increasing the chamber temperature rarely helps.
Often it is possible to reduce the effect by tilting the part to change the slope of the overhang 'though that might require more, or at least different support.
I would first try tilting it 30° - 45° in the Y plane, if that doesn't work try the X plane.
As a newcomer to 3D printing you will encounter a number of such subtle design and print constraints; welcome to the learning curve.
Cheerio,
RE: Issue With Print Lifting From Supports on One Side with PETG
Big thanks for the response and help. I’m posting the 3MF file with the settings from my last attempt ( razor_distance12 ).
I think you’re right, because the print where I lowered the temperature to the point where the PETG came out matte and brittle was also the one where the lifting was the smallest. It was almost good, but unfortunately, due to the low temperature, that part also became very easy to break.
I will definitely try changing the printing angles. But at least I’m a little calmer knowing that this is not some major mistake in my settings, but rather a problem with the topology or the general shape of the object.
Maybe I will also design the part with supports fused directly into the model on the sides, in areas where I can later easily remove them with a knife and light sanding.
Once again, big thanks for the prompt help.
RE: Issue With Print Lifting From Supports on One Side with PETG
Armchair thoughts, but I'd try printing with the part resting on the curved blades, using a brim. Use organic supports painted just on the couple overhangs remaining on the one side. Everything else stays more or less vertical.
That's an awkward shape for 3D printing. Try @conrad-2's suggestion or even consider splitting it into two parts for later assembly.
But I reckon I was right about difficult geometry.
Cheerio,