Hi Roy
I believe you. In my mind, the only way that there can be any up and down movement is if the slot in the u1013 is wider than the diameter of the inner most an960-616 washers on the axle bolt.
I’m sure that’s the case by a very small amount. 1/32 I suppose is possible. And the geometry then would allow maybe 10/32 or 5/16 total movement at the pant TE.
Which could be what you are describing.
But I don’t have that. I know that when I grab my wheel pants there is negligible movement. There is barely discernible flex if I muscle it but no play. 250h too and plenty of gravel and grass so it’s had a chance to loosen up. I generally give all 3 pants a push/pull on walk around so it’s familiar.
One possibility is wear in the screws that hold the pant to the U1013.
As this isn’t my first rodeo, all my pants have a few layers of CF plus another layer or 2 of BID between the pant and the bracket. This adds a fair bit of thickness.
So countersinking the wheel pant for the #8 screws goes nowhere near creating a knife edge in the fiberglass. It’s rock solid.
Maybe check for play there.
Cheers
Rich,
Totally possible. My pants only have about 60 hours on them, and I didn't notice it until after paint. After looking at it and contemplating, I chose to live with it, and applied the rubber around the gear leg hole, to kill any sound of the hole area rattling on the gear leg, and a bit for aesthetics. I haven't seen any wear in the rubber, but that only has about 25 hours on it. I painted over the set screws for the mount, because, hey, I don't need to mess with those anymore, right????
So I'm reticent to go full throttle on what I deemed a minor nuisance, and add all that repair work for the paint. For me, it's a monitor for now. But like I said, I don't have major movement, and I'm not bumping my gear leg fairing like the original poster. I just wanted him to know that I have seen something similar, maybe not as extreme, but similar. I should add that I have to provide a fair bit of force for it to move, but I think it's less force than say the break out for the nose wheel to turn, it's a pretty long lever arm.
For the original poster, I did have to increase the gap between the leg fairing and the nose pant (taken out of the fairing) because I found that when taxiing in a tight turn near the stops the pant would rub the bottom of the leg fairing. Maybe that's your culprit for the paint rub?
I have looked at the track and don't see any wear that would have created the movement, nor scarring, or brightening or deformaties in the aluminum. But you bring up a good point in that I could replace those an washers pretty easy and see if that makes a difference. Or at the very least micrometer them against a new washer and see if there is any difference. It wouldn't take much play to create the movement I see, but they are pretty tight during install.
I didn't add layers when fabricating.... man, hindsight... so I definitly don't have the rigidity you do. I don't think the screws are moving, as I'm not seeing any deformation in the paint, but like I said, you can see the whole part flex a bit if you push on it vertically. If you can imagine, pushing down on the TE causes the front top to move up and the front sides to pinch in, not a lot, but it's there. I filled per plans, and used a pretty rigid flox, but I didn't add layers to the wider area. That alone is probably a bit of the difference.
Last thought for the original poster is to double check break out force for the nose wheel turning. Basically checking the clamping force on the pinned nut on the bottom of the gear leg, I know that I had to tighten that nut twice while flying the 40 off to keep the force correct, and is really apparent when it's not correctly set on the loose side, as that nosewheel can and will flutter back and forth when setting the nosewheel down. I don't know if that looseness can translate to the seesaw motion described, but it's worth checking. And if you have a rub when the wheel is hard over in taxi, then that flutter will definitly cause it to happen.