The original plastic knob on my MasterClass Kitchen Blow Torch had failed where it connected to the D shaped shaft that controls the gas flow.

The housing needs to be disassembled for replacement as the knob flange is retained in a groove in the housing.

I increased the dimensions of the hole that engages with the shaft by 0.3mm to allow for print shrinkage.

I've also included the Fusion file in case you wish to make any changes.

Printed up side down (flange up) with supports.
PLA
0.2mm layer height with 6 walls and 25% infill
0.4mm nozzle