These are meant to be attached via 2 m3x8 screws and 2 heatset inserts in the bottom frame. I bet that a friction fit using only the frame rods would work just fine though, and that way you don't need to reprint your whole bottom frame.
BOM (for 3 feet) is:
3x Rubber Feet (CAD was made with Voron Trident spec in mind)
3x M5x16 Screw (BHCS or SHCS doesn't matter)
6x Heatset Insert (voron spec)
6x M3x8 Screw (BHCS or SHCS doesn't matter)
Post a make or tag me on the Rolohaun server if you end up using these, thanks!
@sasha hehe
The author marked this model as their own original creation.