Just after I bought my Wolverine Jig system with the jig for side grinding
gouges, I dropped that jig and broke the plastic knob into a million pieces.
Ever since, I have been making do.
A couple days ago, I turned 2.25" dia knob to replace the broken one.
Frankly, I recommend you breaking your plastic knob off and doing the same
I find it more user friendly....
Ridgefield, Wa USA (10 miles north of Portland, Ore)