The job
Knobs are the most common discontinued plastic part on appliances, test equipment and control panels, and the bore is where they fail. This knob is a parametric family, diameter, height, shaft diameter, flat width, grip scallops, pointer and set screw are all inputs.
The bore is modeled at the size that prints to a snug fit on the shaft. Hole shrink on the printer is size dependent, so the model applies a banded growth measured on calibration coupons rather than a single offset, and the slicer's own hole compensation is left at zero.
Because the knob is built as a solid CAD model, the same file exports a design intent STEP for the customer's records or a machine shop, and a mesh for the printer that passes the same gate as every other part.
