Propeller

Tonight I finished safety wiring the prop attach bolts. I had previously wired two of the 6 bolts, but had left the others so I could move on with other tasks. At the time I was working towards a deadline – moving the fuselage to the airport – and didn’t want to spend more time on the task. The first two bolts had been a real pain, and I had redone the wiring several times before I was satisfied that it didn’t suck too badly.

For the remaining four bolts, I started by practicing with the thinnest safety wire I have, which is much easier to work with. After figuring out the routing, the length required, and any other relevant details, I switched to the large diameter wire and completed the task. The bolts are wired in pairs, and each bolt has a hole through the center where the wire passes. Because of the varied orientation of the bolts, each one presents a unique challenge in getting the wire through the hole. I was lucky that only one bolt needed loosening and reorienting, and I was able to get all the others to work without adjustment.

In the end I was quite happy with how it turned out, and found that a little practice and lots of patience definitely helps.

It’s hard to reach the prop bolts with a regular crowfoot, so I bought a special prop-torque crow foot. I looked at a few options and decided on the Anti-splat Aero tool. It’s well thought out and did an excellent job. There’s a good video here that shows the tool in action.

The first step is to torque all bolts to 40 inch pounds, then to 60-70 foot pounds as the final torque. With the extension tool, I calculated 35 and 57 foot pounds. I measured the length of the arm of the torque wrench and the length of the extension and used the formula T1 = T2 * L1/L2 where T1 is the torque on the wrench, T2 is the target torque value, L1 is the arm of the torque wrench and L2 is the arm of the torque wrench plus extension.

Then final torque to 60-70 foot pounds (calculated as 57 on the tool). by holding the prop in one hand and torquing with the other I was able to torque all 6 bolts up myself.

The next step is to safety wire these bolts in pairs. That will be challenging due to the orientation of some of the bolt heads. Undoubtedly I’ll need to back some of these off to thread wire through and then re-torque.

Today was a major milestone day, we installed the prop! This was something I’d be holding off on, but with my parents here to help, it was a good opportunity to get it installed.

The first step is to remove the a cap which then allows oil to pass into the constant speed prop hub. There are different methods, but having never done this before I thought it was best not to drill anything, and instead try to remove it with a rod and hammer. Since I couldn’t bring myself to hammer away on the end of a very expensive engine, I let Dad do the job. His steady hand made this an easy task, although we were surprised at how much force it took to eventually pop it out.

The prop needs a couple of spinner plates mounted before it’s attached to the engine, so we followed the manual and Vans instructions to install these.

I also cleaned out the area behind the cap we removed to ensure the prop would mount cleanly.

Borrowing my neighbor’s engine hoist, and with a strap suspending the prop, we carefully hoisted, positioned and installed the prop. It only goes one way, and cannot be rotated at this time, so we had to carefully measure the clearance between the tip of the prop and the garage door, and other shelving. It fit with about 1 inch of clearance. I think I’ll find a way to put the plane into the garage nose first, which will solve the clearance issues, and maybe allow me to keep the canopy installed.

Everything went well today, and I’m stoked to have the prop on now. None of the prop bolts are final torqued, I’ll wait until I’m confident it won’t need to come off again before doing that.

Today I unboxed the propeller, which has been sitting in its original shipping box for about a year. I wanted to verify I had everything, and to see how it all fits together. I also decided not to install it right now, as my panel is coming soon, and I’ll be working on that next. Once I’m done with the panel, and all associated wiring, I’ll come back to the engine, prop, and the cowling.

I started working on the spinner mounting plate, which needs some match drilling and cutting to get the two pieces aligned. I managed to get all the shaping done, and to spray a coat of primer on it.