I modeled up some replacement base plates for my 18v Ryobi trim router, I made a square version as well as a round version. Additionally I made versions to fit some template bushings I bought from harbor freight
https://www.harborfreight.com/router-template-guide-set-9-piece-59369.html
It may work for other template bushings, here are the dimensions to check:
Hole size dimensions:
Center hole I.D = 1.2 inches
Center hold counterbore O.D = 1.4 inches
Center hole counterbore depth = .1 inches
I printed mine in ABS with 30% infill and .2mm layer height, but I imagine PLA, PETG, ABS, PC, or any reinforced nylons would work just fine as well. Supports are not required for the non-template bushing versions, however the template bushing versions will need supports for the center counterbore. Additionally for the square bases I added little pads 1 layer thick at the corners to help fight against warping for materials prone to warping. The intention was for them to be trimmed off after printing.
The author marked this model as their own original creation.