For some reason I've been having quite the time with my gear towers. When fitting the first one into the fuselage (haven't tried the second one yet), all of the bolts went in fairly easily, but the whole outboard portion of the upper and lower weldment that fits against F-904C doesn't sit flush. I've checked and checked, and there's nothing that is interfering and keeping it from sitting flush. Am I missing something, or is this common and it'll all suck together once the wing spar bolts go in?
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Gear Tower Fit
- Thread starter skelrad
- Start date
PaulvS
Well Known Member
Something must be amiss because those are both rigid parts and there isn't that much flex when the spars are in and therefore the bolts shouldn't be expected to fix whatever is causing the misalignment.
If you put the gear leg bracket on a known flat surface, does it sit true? If it is held in position against the spar, without any bolts, does it sit flush?
If both parts are flat then something else is binding or interfering. Maybe it will be more apparent in the morning!
If you put the gear leg bracket on a known flat surface, does it sit true? If it is held in position against the spar, without any bolts, does it sit flush?
If both parts are flat then something else is binding or interfering. Maybe it will be more apparent in the morning!
I took the gear tower out to look at it again. When placed on a flat bench, it does have a slight rock to it (about 3/32"), so it's not perfectly flat. If I bolt that inner portion to the bulkhead first, it pops the outside portion up that extra 3/32". There is also an issue where a weld on the mating surface sticks out quite a bit as well, which even if the part were flat wouldn't allow it to lay flush. I emailed Van's to see what they recommend doing. I can grind the weld flat, but not sure what to do about the part being slightly out of flat to begin with.
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Good call. I did already find that interference and ground down the weldment there to clear the rivet. I was sure that was it, but it didn't make a difference unfortunately. As soon as I bolt the inner portion of weldment to the bulkhead, the outer portion won't lay flat. The weld that is sticking up is part of the problem, but I think the overall flatness is as well.
I heard back from Van's. I can file the weld down, but that's not going to fix the issue of the part as a whole not being flat. I'll have to use washers or shims. Even that's not going to be straight forward, given that the part is not uniformly offset, but is bowed. I'll start by fixing the weld first, then see what that leaves to correct.
kentlik
Well Known Member
If it were me I would take a known good straight-edge tool and with the weldment on a bench check the trueness of the surface that aligns with the spar along its total length. It may be flexing out on both ends. If it is just the one end pictured I would start searching all the areas it should be 90° on the weldment in that area. You may have distortion due to welding and the weldment may need to be adjusted. It happens often when welding parts together.
If it can be adjusted into the correct alignment you will likely need to work the material beyond where it needs to be to get it to stay in the correct true position.
