Drilling axles for cotter pins
I got all three gear legs lifted and blocked up high enough to get a wheel on one leg at a time. I started with the left main. I installed the wheel after cleaning up the axle enough to get the bearings on. I then threaded on the nut. The next trick is to figure out exactly how tight is “sung”. I decided snug, in this case, meant the nut only tightened by hand and only so much as to eliminate any play in the wheel and cause just a hint of rotational drag in the bearings. That is the tightness of my wheel axle nuts. Ok, so then I used the automatic center punch to mark one top cotter pin hole. Hmmm… It landed directly on top of a thread. I looked at it and thought about this for a few minutes before I made a big fat mess of things. I just barely hit the thread with the center punch, not enough to deform it. I took the nut and wheel back off (no problem spinning the nut back off because I was careful not to hit the thread too hard). More looking and thinking about how I was going to drill the hole on the other side of the axle (bottom). Yeah, I could get under it with a right angle drill or something, but I sensed hours of frustration down that path. Ok, we’re going to pull the gear leg back off of the plane and do this on the bench. Oh yeah, and I’m drilling the holes with an electric drill by hand. I can do this kind of stuff (drilling a hole through a threaded axle) better by hand than in my current drill press. Yeah, I have a little disdain for my old crappy Jet drill press, but I’m about to resolve that :). A big pretty Clausing is in my near future.
So, I jacked the left side up a little more and put a saw horse under the fuselage just in case and pulled the one bolt that holds the gear leg. It slid right out as expected and was up on the bench in just minutes. No need to do all that mess on the floor with limited access. What next? Up on the bench, I clamped it in a drill press vice just for some stability. I then ground down the thread with my punch mark on it. I used a tapered grinding stone in the dremel. This created a flat spot where I could start the drilling and worked like a charm. I turned the drill pretty slow and kept it lubed. I opened the hole up to #30 and touched up the threads a bit with a file. I threaded the nut back on and indexed the hole to mark the other side and repeated the process. It all worked out pretty much as expected with little frustration or misalignments.
Ok, so this all took me a couple of hours to drill two slightly tricky holes. I got things cleaned back up and the gear leg reinstalled with the wheel on it. One down two more to go .
