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Landing Gear Mount - Section 29, p21, step 3

R

RV6-KPTW

Well Known Member
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Hi,

I will call Vans today but am wondering if others have experienced very tight fit of AN5 bolts on the landing gear mount? I don’t think I can get the bolt into this hole without a large hammer. The AN3’s and 4’s seem fine - snug slip fit.

I measured the hole in the spar and the grip on the AN5 and they are largely the same. I could freeze the bolt and maybe get a better fit but I will never get the bolt out. This step is a trial fit for match drilling so that is not appropriate.

Thanks

IMG_0963.jpeg
 
I remember having to use a long piece of something plus a hammer to get that bolt into place. I also think I just didn't put it all the way through for this step. I put in the other bolts got this one a little bit in and then added other bolts as I proceeded with the match drilling.
 
The powder coating can bleed into the holesand make them tight. Be sure there is none there. It can be scraped out. If not, try putting grase on the bolt. Can also tap the mount with a rubber mallet as you drive the bolt to help with alignment.
 
Thanks.

Larry, this is not a mount alignment issue. The hole in the spar is the issue. I pulled the mount and tried appropriate bolts in every hole. Everything was a snug slip fit except the AN5 hole which would not allow insertion beyond the initial grip section. I will freeze some AN5s and see if I can do better.

To get past this, I did as Kirkbaeur suggested.

I did send a note off to Vans asking what size they ream that hole to. I think it is a tad too small and am concerned about a partial insert of the bolt at final.
 
RV6-KPTW said:
Thanks.

Larry, this is not a mount alignment issue. The hole in the spar is the issue. I pulled the mount and tried appropriate bolts in every hole. Everything was a snug slip fit except the AN5 hole which would not allow insertion beyond the initial grip section. I will freeze some AN5s and see if I can do better.

To get past this, I did as Kirkbaeur suggested.

I did send a note off to Vans asking what size they ream that hole to. I think it is a tad too small and am concerned about a partial insert of the bolt at final.
Click to expand...
Possible that they got too much of the anodizing solution in there. Based upon the other holes fit with the bolt, it would seen you may need to ream that hole. Do you have enough access to do that. If the spar is .0310, then something is off. Spec on a bolt should be 0311 or under. Unsure on the tolerance range of AN bolts. I would expect the hole in the spar to be at least .03125 and very possible they ream it to .03135 or 4. Usually a slip fit is .001 or better, so doubt you are going toget that in and be able to remove it later, so resist the temptation to freeze it and slam it in, as you are already at or near a loose interference fit. You could chuck up that bolt and see if you can knock a thou off with files and sandpaper. I often do this on the lathe to take off the last thou. But reaming it back to 03125 would be the best option. Worth checking with vans to get the spec though.
 
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I tried frozen bolts (for fun and education) and got about 1/4 inch into the grip. So that is not a solution. I ordered a 5/16 reamer and await arrival. Access is going to be an issue. Wish I checked this prior to mating mid and forward fuse in Section 28, page 9.
 
lr172 said:
Curious if it was anodizing material or Alum. Wondering if a couple of drips or blobs were in there.
Click to expand...
No sure. Was not able to identify removed material. Must have been pretty small. In the end, taking a look in the bolt hole, I did not see any bare aluminum so I suspect anodize.

Thanks
 
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