These knobs fit flatted or flat shafts and are designed to break before the shaft does, thereby protecting the more expensive heater control or timer elements. The only problem is that its hard to find replacement knobs that match the originals.
Step 1: Can it be fixed?
This knob split lengthwise. Sometimes they chip at a diagonal through the cylinder of the knob. Both kinds of damage can be fixed with this repair.
Step 2: What you'll need.
1. Small Pipe Cutter
2. Brass or Aluminum Tubing
3. All Original Parts to Broken Knob
The pipe cutter was about 5 bucks. Get the tubing at a local hobby store. Take the knob with you. The diameters come in increments of 1/64th of an inch (I think). Select the size that fits snug over the cylinder of the knob.
Step 3: Cut the Tube
Measure the knob cylinder length. Cut the tube to cover most of that length, but not quite the whole thing.
Step 4: "Sleeve" the knob.
Step 5: Replace knob
Match the flatted side of the shaft to the corresponding flat side of the knob and slide it back on.
Step 6: Finished Repair
You are now ready to resume making toast! Keep the tubing somewhere you will be able to find it, the other knobs are sure to break sooner or later. Done at TechShop Detroit!