Fretboard Radius Jig

I didn't find any free design for such feature so this is my first attempt to create a fretboard radius jig that can be used for 7.25", 9.5", 10", 12", 14" and 16".

The trolley and the jig itself are using bearings (8) to slide.
The axles diameter is 7.5mm ,length is 7 mm to comply with standard (inner diam. 8mm, thickness 7 mm outer diam. : 22mm)

It's actually a bearing-mounted carriage. The slides can be interchanged to achieve the desired radius thanks to their tenon fastening.
As I'm not sure the tenons are symmetricals therefore a set of two sliders (Left and right) is available for each radius value.

I didn't create yet the locking mechanism for the bearings.
The freeCad file is available for download, feel free to modify and Remix !