Brief Description: landing gear prep work for lower skin riveting
I did some landing gear prep work as the lower front skins will be riveted on soon and I will lose access to this area. I saw the two sets of front facing nutplate holes first and freaked a little that they aren't dimpled when you look at them from the underside of the skin...thinking I would need to dimple those holes, I climbed under the flipped fuse and was preparing to dimple the holes when I noticed that they had already been countersunk! Good deal.
Grove spec'd the outer landing gear pads holes/bolts at 5/16" - up from 1/4" so the first order of business was to up-drill the holes. I stepped it from 1/4" to 9/32" to 5/16" to keep the hole nice and centered.
Then it was on to the inner landing gear plates - which only have the middle holes drilled in them so far. There are two semi-necessary holes in each pad that gets drilled to 1/4". I say, semi-necessary, because those pads aren't going anywhere with that bolt going thru the middle of the landing gear - they would probably rattle a bit so I will go ahead and secure them to the floor. Those four holes took quite a bit of time because each time I would measure for two of the holes, I wanted it to be accurate, so I re-installed the landing gear. Then I would un-install it to drill them, then re-install it to check the holes...etc. etc. 3 of the 4 turned out perfect - but the fourth I had to upsize the hole to a 9/32" as the hole was very slightly misaligned...not a problem, like I said, that inner landing gear pad won't be going anywhere.
I also measured and drilled the brake line hole in the bottom floor so the brake lines can go into the top of the landing gear - where the brake line hole has been predrilled.
landing gear prep work
Inside looking up
brake line hole in floor skin and the drilled LG pad