Judging when supports are required?
I got my Prusa Mini+ a few days ago and have been printing a bunch of random stuff as I learn the basics. Im a bit confused on the auto generated supports PursaSlicer is giving me and how supports should work in general. For example, I was printing this gorilla from thingiverse and here are the auto generated supports with a overhang threshold of 45 degrees (which I saw was commonly recommended as the angle limit without needing supports):
However as a test, I printed this without any supports at both 1" and 2" tall and both printed just fine. I also noticed that the Benchy boat that comes with the printer prints just fine without any supports despite having a canopy. Anyone have any tips on how to get an idea of when you do and don't need supports? Am I using the auto generated supports correctly? Thanks!
Best Answer by FoxRun3D:
One can write a treatise on this subject! Here are just some thoughts:
The Prusa can easily print overhangs larger than 45 degrees, so that number is conservative. You'll develop a sense of what's reasonable. You can also print an overhang test model to see what it looks like and what you consider conservative. There are ways to adjust layer height, extrusion width, temperature, etc. to get by with a surprising amount of overhang. Also, overhangs away from the parts fan tend to be more fragile.
I usually look at autogenerated supports but most of the time end up using the paint-on support function to manually place supports where they're really needed.
I've never printed a Benchy in my life, so I can't comment on the canopy question but it it's a straight horizontal surface, many horizontal surfaces can be "bridged" by the printer, with no supports required.
Here's my set of basic support settings (for 0.4mm nozzle, 0.2 mm layer height):
Style: Snug
0.25mm top z distance
3mm pattern spacing
4 interface layers
75% xy distance
0.2mm interface layer spacing
0mm first layer expansion
RE: Judging when supports are required?
One can write a treatise on this subject! Here are just some thoughts:
The Prusa can easily print overhangs larger than 45 degrees, so that number is conservative. You'll develop a sense of what's reasonable. You can also print an overhang test model to see what it looks like and what you consider conservative. There are ways to adjust layer height, extrusion width, temperature, etc. to get by with a surprising amount of overhang. Also, overhangs away from the parts fan tend to be more fragile.
I usually look at autogenerated supports but most of the time end up using the paint-on support function to manually place supports where they're really needed.
I've never printed a Benchy in my life, so I can't comment on the canopy question but it it's a straight horizontal surface, many horizontal surfaces can be "bridged" by the printer, with no supports required.
Here's my set of basic support settings (for 0.4mm nozzle, 0.2 mm layer height):
Style: Snug
0.25mm top z distance
3mm pattern spacing
4 interface layers
75% xy distance
0.2mm interface layer spacing
0mm first layer expansion
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...