Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:3449230.

This remix makes the feet a little stiffer, and rotates 90 degrees in relation to the aluminum extrusion. Finally I made the horizontal sections solid for added strength.

The original snaps on the inner side of both 2020 profiles, for a single, that is not possible.

This is a remix of the original feet, as well as my own PLA-related strength enhancements.

Two variants:

1. Snap-in. These should snap in the extrusion and stay there until forced out. If they don't fit your profile, let me know.

2. Slide-in. The preferred method; these fit perfectly, but you need an open end and unobstructed path to the position you want the feet in. Most likely, end-caps, bolts and other stuff is in the way :)