I have seen a few of these on Thingiverse / Printables etc but none was exactly right and so decided to draw and print my own.
The handle and cover are in ABS and the rotor is in PETG.
You could probably get away with PLA for the body but the rotor needs to be in a more flexible material.
The cover to the handle is a bayonet type fitting and I think works better than the screw / push-fit ones.
The magnet is 8 x 3mm and is optional, it just stops the bit falling out.
If you only have smaller magnets then just glue it in.
The torque when tested was around 1.4Nm. This will depend on print settings and materials used.
Printed on a Voron 2.4 with a 0.15mm layer height.
Printable STL files to enable better print calibration for your Klipper based 3D printer.