I've added a hemicylinder to make this a knob with a D shaped fitting to replace a broken knob on a crock pot. At the given scale, the knob will fit a D where the diameter of the (imagined complete) cylinder is 1/4 an inch; the void is thus the radius or 1/8 an inch. This is in progress until I determine if the D needs to be inset for flush mount.Print with full fill or it will probably break really quickly where the inside meets the outside near the end of the print--you can see as much in the photo, which was printed at 25%. If done on a heated platform you may need to trim the flare at the bottom for it to fit.