Drilling main gear axles for cotter pin

[647jc]

I’m ready to drill the main gear axles for cotter pins and really dreading it from all the horror stories I’ve read regarding misaligned holes and getting the aluminum nut threads all screwed up. I have an A series plane and I drilled the nose axle last month with the supplied steel castellated nut in place. I drilled through the castellated slot keeping the bit up against the bottom of the slot and drilled from one side and then the other, had no problems getting the nut off afterwards and the axle threads did not appear to get mangled in the vicinity of the hole. So, I’m thinking I could use the same method and steel nut on the main gear axles. The distance from the bottom of the castellated slot to the face of the steel nut appears to be the same as on the aluminum nut, I would need to be sure and keep the bit held up against the bottom or end of the castellated slot (probably with a piece of wood) but other than that it shouldn’t be any different than drilling the nose axle. This method would insure in the holes are aligned and the aluminum nut doesn’t get damaged. Any comments from others, has anyone else used a similar method?

[andrew phillips]

I tried the vans method on the main gear first and it did not work well on either side. Months later when I went back to finish up and re-tightened the wheels I found that the pin location was not all that good do I drilled another one. I drilled the holes slightly undersized with the method you used for the nose wheel. I then removed the nut and drilled out both holes to a larger size. Worked perfetly for me on both sides.

[ArVeeNiner]

You know, I was dreading it but when I did it, it was a piece of cake. No problems at all. Nothing galled or got screwed up.

I used a method that I got on this board. You basically drill with the nut in place. It was the Tony Spicer method here: http://www.vansairforce.com/communit...light=axle+nut

Kelly Johnson
RV-9A Finishing

[647jc]

Just a follow-up post on drilling the axles with the method I described earlier using the nose gear steel castellated axle nut as a guide. I just finished drilling the axles and had no problems, procedure worked great, the holes came out aligned and I didn’t mess up the aluminum nut threads in the process since I used the steel castellated axle nut off the nose gear (one advantage of building a nose dragger I guess). After drilling both sides (front and rear) with a 12” #30 bit, wheels still on but deflated (also taped thin aluminum scrap sheet over the rim so the drill bit didn’t scratch or gouge it), I removed the wheels and enlarged the holes with #27 bit to make inserting the cotter pin easier. Job wasn’t as bad as I thought it might be.