Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4856403.
A pair of arm guards/protectors with motor protection for the FBXPro215 frame - a knockoff of the DQuad Obsession: https://www.cyclonefpv.com/products/fbxpro215-drone-racing-frame?_pos=1&_sid=1d30b4bf8&_ss=r
Each guard attaches with a single zip-tie - I prefer that so the motors are solidly screwed to the arms and screws are easily accessible for repairs. The center "strap" should easily push aside if you need to change a bell.
13 May 2021: Revised part with tighter tolerances, removed excess overhang that needed a bunch of support (but kept a little on each side to make it snap on nice and snug), added locator pin and motor protection
This was the first thing I ever made in F360 and this video was extremely helpful in learning how to do it. Definitely recommended if you'd like to try it yourself, especially for knockoff frames that don't have any prints available for them. https://www.youtube.com/watch?v=QfPJMprkIz8