Ariens Snowblower Knob

Replacement knob for Ariens Snowblowers, part number: 07509600 (maybe, not 100% sure)

here's a link to buy one, they're $24.55 currently (!): https://www.repairclinic.com/PartDetail/Knob/07509600/1770004

I bought my snowblower and it was missing the knob to rotate the chute. The shaft is 3/8" diameter. I bought a 3/8" push nut at the local hardware store for 30¢, and printed the rest. filament cost: $1.05. I saved $23 printing this vs. buying it. The code (sans variable definitions) is rou