Router Spline Jig

This is a jig for cutting splines using a router, which is helpful when adding splines to larger pieces that cannot easily be held safely in a tablesaw jig.

The holes are sized to accept M4 heat-set inserts and assemble with 10mm M4 bolts.

The guide rails are not required if the router is equipped with shallow template bushings. When the guide rails are installed, this should fit a Bosch RA 1166 plunge router base and a trim router should fit between the guide rails with about 1/4" of space between the main supports.

Printing an earlier design in PETG with 4 wall loops and 15% gyroid infill resulted in minimal flexing of the support structures.