T-Handle Hex Bit Driver (REV 2, Parametric))

This model offers an alternative to standard, screwdriver-shaped handles.  It uses the same parametric model from my hand drill, but with modifications for a hexagon hole.  After gathering several drivers here in the USA (both name brand and budget-bin specials) I consistently measured 6.3 mm across the parallel sides of the hex.  

Revision 2

I updated the design to use socket head cap screws and square nuts.  Button head screws will still work of course.  With more practice, I also improved the CAD file.  It is much harder to break any of the operations.  Screw length now determines the handle thickness, and I double check that the handle length is sufficient.

I also added a feature to lock a bit driver in place using the small rounded section near the end of the shaft.  In case this shape is not universal I also include models without it.  

Supplies

You will need:

• (5) M3 square nuts (DIN 562)
  • or (5) M3x5x4 heat set inserts
• (5) M3x12 SHCS

Clamping & Tolerances

I modeled for several tolerances to make sure you can have a wobble-free fit.  Similar to the drill handle, the tolerance needed a small adjustment to get enough clamping pressure.  (In the parametric design file, the user parameter “hex_tol” has a -0.15 mm adjustment.)

Notes

I recommend using a 0.1 mm layer height and 0.4 mm nozzle diameter for the best success.  I used 0.24 mm for the first layer, but this should not have a large effect.  

If you want to make a custom size hexagon hole, I have included a step file.  Use your favorite CAD to extrude the hole.  If you want an entirely custom handle or other modification, I include the f3d file with design history.  The primary design elements have user parameters.  

Minor update: I reorganized the downloads so that individual parts are separated into their own file, and compatible parts are bundled together into a zip file.  I still include stl and step files.

Minor update: Updated pictures.

Thanks for visiting, and enjoy!

I remixed my own design to fit a magnetic hex bit driver.