When I last wrote, I was in the middle of making a new set of rotors for Goliath to address the RPM/power mismatch between the rotors and the engine. After a lot of work, the last of the new rotors was pulled out of the vacuum bag two days ago. Here is a shot of the four new propellers after having the excess material trimmed off.

All that remains now is to cut out the center hole, sand the rotors smooth and apply a final coat of paint.

One other item that has to be addressed before the next test is to swap out the rotor mounting bolts again. Previously the 1/4" grade 5 bolts were replaced with 1/4" grade 8 bolts. They seemed to work, but the other day it was found that one of the new bolts had broken in the same manner as the old bolts. If you haven't seen it, this is what happened previously:

The 1/4" bolts will now be replaced with 3/8" bolts. This will require drilling larger holes through the pulleys and the bushing.

In the future, the plan is to make a custom pulley. The custom pulley will be aluminum and will be a single piece instead of the pulley/bushing combination. To prepare for this, a 3 in 1 Smithy (Mill, Lathe, Drill Press) was obtained to make the custom pulleys and this week, the aluminum pulley stock arrived.

The pulley stock is 10" long so I can make 7 or 8 30mm wide pulleys with it. It's been a long time since I've worked on a lathe, and I haven't made a pulley before, so we'll see how it goes.

With some luck, the next post will be a summary after the next test is completed.