3D-Printable thumbscrews for 7x10/14/16 Minilathe change gear cover

[Saltfever]

Since you are 3D printing them I assume only moderate torque is being applied in use. Just buy socket head screws the correct size. Turn some knobs from aluminum and drill a hole with an interference fit to the socket head. Squeeze them together in a vise.

If you search enough you will find some with serrations around the head. That will greatly enhance the "bite" (i.e., press fit).