GlasairProject.com Propeller Information

Propeller:

This project started with the idea of keeping it simple. I initially thought I could use a fixed pitch propeller and compromise the top end performance. I purchased a full composite Global Aircraft QCS-10 ground adjustable propeller. This propeller turned out to be a work of art. However, after lots of calculations and some practical experience from a Glastar builder with a similar ground adjustable propeller on a Subaru, I decided that it just wasn't safe to use anything but an in-flight adjustable propeller for this engine.

I recently purchased a Quinti three blade, electric, in-flight adjustable propeller. I designed a control unit for this propeller to allow operation from a set of remote, stick mounted switches. It isn't constant speed, but does have the capability with an upgrade from the manufacturer. At this point, I am happy with the non-constant speed setup.

To install the Quinti on the Marcotte gear drive, I had to fabricate a way to mount the brushes that transfer the electricity to the slip rings. I used the machined surface of the drive unit casting as my attachment point. After carefully lining up the brush assembly, I used a 12" long drill bit, through the brush holder mounting holes, to drill the pilot holes into the casting. Then I tapped the holes with a 1/4"-28 tap. I used some 1/4" id x 7/16" od aluminum tubing, cut to the proper length, as the stand-offs. Last, I ran long bolts through the holder, through the aluminum tube and into the casting.

The Marcotte prop flange had to be slightly modified as well. The Quinti came with 5/8" drive lugs and 3/8" studs installed in the back of the prop hub. The gear drive only had 3/8" holes for the studs. I had Davis Tool Inc machine the gear drive hub for the drive lugs. Doing this required that special washers be fabricated to keep the nuts from pulling through the hub. I had them make me these washers from stainless steel while they were machining the hub.