Author Topic: Worn landing gear scissors  (Read 2741 times)

Bill Poynter

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Worn landing gear scissors
« on: April 13, 2012, 12:58:33 PM »
While examining the scissors on some Cadet landing gear legs that I recently acquired, I noticed that the bolt holes in the scissors were worn to an oval shape.  The corresponding bushings in the gear legs showed almost no wear.  It appears that the bolts had been pivoting in the thin hole of the scissors instead of the wide, well supported bushings of the gear legs.  When you combine this apparent design shortcoming, with the fact that itís operating in a dirty, gritty environment, you get very rapid wear.  You never see high time Cadets, but there are sure a lot of them with badly worn landing gear.   

I was thinking about how to better lock the bolts to the scissor when I remembered seeing something unusual on the scissors on my project Cadet. 

That Cadet has a couple of gobs of weld adjacent to the bolt holes in the scissors.  The weld has been machined off at a 90 degree angle so that when a bolt is inserted, the weld prevents the bolt head from turning.  It doesnít look too pretty, but it works.

Does anyone have an idea how to improve on this?   

Bill Poynter

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Re: Worn landing gear scissors
« Reply #1 on: April 29, 2012, 08:42:57 PM »
When faced with having to repair worn bolt holes in the landing gear scissors,  It seems to me that the obvious fix is welding and re-drilling them.  The welding part is easy.  It's drilling the holes in exactly the right position and angle that's more complicated.  If after drilling the holes, the front bolts in the upper and lower scissors are not exactly parallel, the alignment of the wheels will be off.  Because the front bolts are so close to the vertical axis of the oleo, a small error in drilling the holes will produce a big alignment problem.  Of course the answer is to make a drill guide/fixture to hold the drill in alignment.  It would be great if we had one that we could pass around to whoever was in need.  Does anyone have an interest in this?