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RV-9A: Flap Motor & Landing Gear Mounts - 1/22/2010
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Time to install the Landing Gear MountsTime to install the Landing Gear Mounts
I took quite a few pictures of this installation. So you will see the best pictures from both left and right installations. First off, I had to use my rounded file to remove part of the flange from the main wing spar, using the existing gear leg hole as pattern. After the fit of the gear mount I noticed that I didn't have to remove any of skin metal in the rear of the existing gear leg hole, only the forward part of the hole. I also found that I had to remove more of the forward part of the gear leg hole than was there originally, just to make sure that the gear mount didn't hit it after all the bolts where tight.
Time for trial fit of the Landing Gear MountTime for trial fit of the Landing Gear Mount
Before mounting the mount (arr-arr), I put in some of the bolts into the holes on the mount and found that the powder coating inside the bolt holes was preventing the bolts from sliding in. So I scraped off the powder coating with my pocket knife. Now the bolts go in without any problem.
Don't forget the shim washer!Don't forget the shim washer!
I decided to be a smartass and experiment with taping this shim washer to the back of the gear mount where one of the bottom bolts go through to the wing spar. To my surprise, it actually stayed in place!
First tryFirst try
The damn thing wouldn't go in! Surprised? At this point, a thousand things went through my head. Do I need to make the hole bigger? Is there something interfering with it on the fuselage. Since I couldn't see under it, it could be anything.
Ah-Ha! Found the problemAh-Ha! Found the problem
There is one nutplate on the flange of the center spar that stops the gear mount from going into place. You can see it in the mirror. So, I simply pushed straight down on the gear mount, past the nutplate, and it popped into place.
Time for the top and bottom boltsTime for the top and bottom bolts
I'm saving the side bolts for later. The top and bottom bolts establish the correct position of the gear mount in front of the main spar. I'm glad I bought this universal joint. It will definitely come in handy here.
The frugal man's extended wrenchThe frugal man's extended wrench
The nuts in the bottom spar are WAY down there. So I grabbed another wrench and taped them together. I also put some scotch tape backwards on the end of the wrench to get the washers onto the bolts.
Put tape on your nuts!Put tape on your nuts!
Oops, sorry, couldn't resist that one. I put a piece of duct tape on the back of the wrench and stuck the nuts on it. This made it really easy to install the nuts in the main spar abyss.
Top and bottom bolts are in!Top and bottom bolts are in!
One additional adjustmentOne additional adjustment
Oops, sorry, I forgot to mention this. I had to remove a little of this angle piece with my Dremel to get the mount in place.
Now for the side boltsNow for the side bolts
The instructions say to drill these holes using the gear mount as drill guide. There ain't no way to get anything, not even an angle drill behind the support that covers these holes. So used a #30 drill bit and drilled straight through the support piece and into the gear mount.
On the flip sideOn the flip side
Here's why I started with a #30 drill bit. I knew that I had to countersink the skin and the part behind the skin, and the only countersink bit I had was a 1/8" countersink. So I did my countersinks and checked them with the screw head that goes in these holes. If I had drilled these holes to their full size, the countersink bit would have danced around and made a lousy countersink.
Now to drill the holes to their full sizeNow to drill the holes to their full size
Pretty simple. I just used the 1/8 inch holes as a drill guide for the larger holes. Now I have a nice countersink around the larger screw holes.
Screws are in!Screws are in!
Here's the flip sideHere's the flip side
The green arrow shows where I drilled a hole in the support to get to drill the hole in the gear mount.
Now for some easy stuffNow for some easy stuff
I drilled the bolt holes and then used my pocket knife to clean out the shavings from under the skin. Then I put the bolts in after deburring all the metal parts.
Here's the flip sideHere's the flip side
Nuts and washers on and torqued.
Tadah!Tadah!
My RV has been mounted!! (oooh)
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