These are replacement feet for the Prusa i3 MK3 to be printed in TPU or other flexible material. They will not work unless printed with flexible material!
The original rubber feet of the Prusa i3 MK3 have a tendency to come off when the printer is moved. They aren't doing a very good job at spreading the weight of the printer either.
These feet are designed to be pushed into the aluminium extrusions without having to disassemble the printer. If printed correctly, they can also be pried out again without unscrewing the end plates, but they definitely won't come out easily.
My printer resides on a stainless steel table, which is prone to vibrate and amplify printing noise at certain speeds. Printing these feet longer (50mm) helped spread the printer weight over a larger area and shrink the open space between the feet, which acted like a drum.
I've added a customizer for this, so anyone can print whatever length required.
STL files are attached for three lengths:
- A short 8mm piece which is good for testing whether there is enough flex to insert and remove the feet. See printing instructions below.
- A square 30x30mm foot.
- My preferred 30x50mm size.
Print settings are really important for this one. Depending on your filament, you may have to vary the settings to get the right amount of flex.
I recommend first printing the 8mm test piece and checking whether you can push it straight into the extrusion. This one is easy to remove, since it can be twisted 90 degrees and just pulled out. Longer prints are more tricky to remove. Mine can still be removed starting at one corner. Once a single corner is out, the foot can be pulled out quite easily.
Mine were printed with Hatchbox TPU. I found that 2 perimeters give the optimal flex to be able to insert and remove the feet. 3 perimeters make the foot too stiff with my material. In order to get some vibration damping, I've used only 15% infill. However, printing one solid infill layer every 10mm helped reinforce the middle. Without that, the middle gets rather squishy, while the ends are less flexible due to the walls. I'm attaching my Prusa Slic3r config file for reference. This can be loaded into Slic3r to get all the same settings, but you can also just inspect the contents, as it's a plain text file. To avoid jams with the Hatchbox TPU, I've had to slow down the print by setting a volumetric limit for the filament and turn off retraction. The latter means that I could only print one foot at a time, as stringing would be horrible when moving between multiple parts.
OpenSCAD. Source is attached. Customizer is set up to allow modifying just the length, but everything else can be tuned in the SCAD source. Sorry about the utter lack of useful comments.