Broom repair coupler (fluted)

Repair coupler for a 21.2 ± 0.3 mm broom handle with internal flutes for rotational stability.

The STL can be stretched to adjust sizing, alternatively the FreeCAD file can be adjusted to accommodate other sizes by changing both, the half-distance from z-axis in the revolution sketch and the corresponding diameter in the pad sketch. I can move this to a spreadsheet variable if requested.

The version I tested (r0) included 1mm flutes. These have been adjusted to 0.8mm for easier use. While it didn't seem needed in my use, CA glue was applied to the seam after joining.