Step 12: Drill the metal angle brackets
- one Simpson GA2 and two Simpson A34 angle brackets.
- cutting oil.
The GA2's center hole is perfectly located for widening. If your propeller wheel has a hollow axle and a quick-release skewer, drill out the GA2 center hole only to fit the skewer, 13/64". Otherwise, widen it to 13/32", to fit the axle.
The A34s already have holes suitable for screws. On the GA2, on the other face from the axle hole, widen the top and bottom holes to 3/16".
If you're not experienced in drilling through sheet metal:
- Make a dimple where the hole is to be, using a hammer and a centerpunch or large nail.
- Drill a small-diameter hole first, then enlarge it with larger bits.
- Keep the bit tip wet with cutting oil (or 3-in-1 or WD-40 as a second choice) to ease the work and save drill bits.