5.4. Working with removable supports
Removable supports are a contradiction. You need supports to keep overhangs in place, but you want them to be easily removable after printing. These notes cover some PrusaSlicer settings that produce easily removed supports when printing PLA.
Note
These notes are based on my experiences with the Prusa i3 Mk3 and Artillery/Evnovo Sidewinder X1 printers. If you are using a different printer, please verify the hardware details are similar.
The key to removable supports is providing enough separation between the supports and the supported part that the support can be easily removed, while still providing support for overhangs. Unfortunately, supported layers are never going to look as good as layers printed without overhangs.
For support to be removable, there has to be a gap between supports and supported layers.
That gap means the supported layer is literally printed in thin air.
You often need to increase the size of the gap (Z contact distance) to improve ease of removal.
The supported layers print without any squish onto layer beneath, so have a circular cross-section and tend to sag slightly.
There are a few things you can try to improve appearance when using supports:
Re-orient the part on the print bed to reduce the need for supports.
If you are designing the parts, you can design in some easily remove “sacrificial supports”.
Slice the part into smaller portions that don’t require supports and assemble them after printing.
Otherwise, finding a good balance of separation is important on the XY and Z axis. Here are the settings I change:
Setting |
Value |
|---|---|
Contact Z distance |
0.25mm |
Pattern spacing |
3mm |
Interface layers |
4 |
Interface pattern spacing |
0.2mm |
Interface loops |
Off |
XY separation |
75% |
Don’t support bridges |
On |
Support settings can be found under Print Settings->Support material in PrusaSlicer.
I find these settings work well for PLA with a variety of prints. PETG can be a bit tricky since it is usually printed with less cooling.
Other slicers handle supports for flat areas a bit better, at least for now.
I use |IM|| for areas with large flat surfaces that need support.
Ultimaker Cura tree supports are very good for miniatures and prints with lots of detail.
PrusaSlicer is improving constantly and quickly, and supports will no doubt get some additional attention soon. It’s one of the few remaining problem areas for PrusaSlicer.
Contact and feedback
You can find me on the Prusa support forums or Reddit where I lurk in many of the 3D printing-related subreddits. I occasionally drop into the Official Prusa 3D discord server where I can be reached as bobstro (bobstro#9830). You can email me directly at projects@ttlexceeded.com.
Last edited on Apr 04, 2021. Last build on Oct 22, 2021.