The square handle on the previous version seemed like it would be better if it were rounder, so I modified it in OnShape to add chamfers to the handle and it's still printable. Feel free to modify the OnShape CAD file!
I printed it in PLA with 50% infill for strength, and it seemed strong enough. You could probably use less…
The author remixed this model.
Imported into Onshape and redesigned with rounder handle.