Replacement knob for a variac transformer, although it could be used for many other applications.

Designed to look look like the original bakelite knob. Kind of Art Deco-ish. Kob includes a pointer extending from the base.

Fits a 3/8 inch diameter shaft

Has two set screw holes for securing to shaft.
Each setscrew requires a standard 8-32 x 1/2" machine screw and flat nut.

Has two set screw holes for securing to shaft.
Each set screw requires a standard 8-32 x 1/2" machine screw and flat nut.

Turn the knob over, base side up.
Insert the 2 8-32 flat nuts into the square holes from the base.
Insert the 8-32 x 1/2" machine screws in from the side holes and screw in to engage the nuts.

12 machine screws, when fully screwed in, will extend approximately 1/32th inch into shaft area to secure.

Designed in openSCAD