I didn't see these anywhere else. I lost/broke the caps when moving my rack, so I threw these together.
They are designed to fit a steel angle measuring 32 mm x 2mm.
Use infill at 100% or enough walls to be solid under the lag for the boot. I used PET-G, but TPU would work well.
The caps are great to prevent damage to items stored on it, they are short enough to not interfere with the rack in it's uppermost position. The feet have a longer boot for stability.
In particular, I modeled it for:
Home Depot Husky 5-Tier Heavy Duty Boltless Steel Garage Storage Shelving Unit in Black (48 in. W x 78 in. H x 24 in. D)
The author marked this model as their own original creation.