Bicyle Rear Rack holder, parametrized

not a full part, must be fused with a holder part. This is just the part that fasten to the rear rack, it won't hold anything as is.

Fully parametrized, so compatible with rear bike rack. The hex head screws will mount flush.

Default values matches the holes on my Topeak brand rear rack and PlanetBike light holder. May match other brands. but again, it's fully parametrized, just measure yours update the values

versioned source at https://gitlab.com/gcb/3dump/