How to drill WD-409 tailspring mount to F-711?

[java]

So I've searched the archives, and found lots of stuff about modifying the bottom of the rudder, how to get at the nut holding the tailspring in the mount, and whether to powdercoat or not, but for the life of me I can't figure out how to drill the mount to the second most rearward fuse bulkhead (F-711).

I have a QB, and F-712 was only attached with a few pop rivets, so I've drilled them out and removed it. F-711, however, is fully riveted in place, and something tells me I'm supposed to be able to do this without drilling out all those nice flush AN426's. I can get a drill inside the tailcone to matchdrill through the holes on the two "prongs" (can't remember their numbers), but how do I hold the tailspring mount in position on the backside of F-711 while I'm drilling?

Do I measure from the plans and drill one of the holes with the mount outside the tailcone (i.e. on the drill press), then bolt in place through that one hole to hold the part to match drill the other?

What did you QB builders do?

Thanks in advance.

[java]

Oh come on... surely someone else here is building a seven tailwheel as a quickbuild?

[Caveman]

Originally Posted by java

Oh come on... surely someone else here is building a seven tailwheel as a quickbuild?

Well I was hoping someone with a better method would answer. I just did this last week and couldn't find any info other than what was on the prints and Dan C.'s site.
I drilled & installed the holder rivets in F712 by carefully measuring to get them where I thought they should be so they miss the rudder hinges. Then I leveled the fuse, leveled the tailwheel best I could with a "string level" (used on chalk lines) across the tailwheel spring triangular plates and drilled away. There really isn't a good place to lay a "Smart level" or Tri-square bubble. I got lucky and hit it pretty close. Be very careful about the bottom rivets on the rear bulkhead as they may be impossible to buck unless you have a special tool. I think most guys are using cherrys and that is what I did on two of them, (It was the second row from the rear and the bottom on each side. If you are off very much you can't even get a blind rivet to seat all of the way in.
Watch the edge distances on the tabs when you go to rivet on the rudder stops. I hope this helps but there has got to be a better way. Use at your own risk!

[mburch]

I did about the same thing: Measure 50 times, measure again, drill the holes, and use CherryMax rivets for those @#$% ones down below that are impossible to buck.

good luck,
mcb

[java]

Originally Posted by Caveman

Well I was hoping someone with a better method would answer. I just did this last week and couldn't find any info other than what was on the prints and Dan C.'s site.
I drilled & installed the holder rivets in F712 by carefully measuring to get them where I thought they should be so they miss the rudder hinges. Then I leveled the fuse, leveled the tailwheel best I could with a "string level" (used on chalk lines) across the tailwheel spring triangular plates and drilled away. There really isn't a good place to lay a "Smart level" or Tri-square bubble. I got lucky and hit it pretty close. Be very careful about the bottom rivets on the rear bulkhead as they may be impossible to buck unless you have a special tool. I think most guys are using cherrys and that is what I did on two of them, (It was the second row from the rear and the bottom on each side. If you are off very much you can't even get a blind rivet to seat all of the way in.
Watch the edge distances on the tabs when you go to rivet on the rudder stops. I hope this helps but there has got to be a better way. Use at your own risk!

Thanks Joe. Just to make sure I understand, I'm reading it as that you attached the tailspring mount (WD-409) to the aft most bulkhead (F-712) using the keeper rivets, outside the tailcone, then mounted the assembly back in the tailcone to drill through the second most aft bulkhead (F-711) into the tailspring mount (now held in position by F-712)?