Left Elevator

Greetings,

I'm a little stumped here - when riveting E-705 to E-606PP, the plans say to machine countersink so that the flush head is on either the forward face of E-705 or the aft face of E-606PP. If it doesn't matter, why countersink at all? Why not just use a 470 rivet? Seems silly to take metal away for no reason. Or... is there something I'm not seeing here? What have y'all done?

Thanks, Greg
San Diego

I'm not sure where you are seeing that information exactly. There is nothing done to the 705 end rib. But just countersink the front of the 702 spar. The 605 elevator horn mounts directly on top of them and obviously needs a flush surface. Then you use 470's to attach the horn. Basically the plan for the right elevator is a little more clear and the left elevator is done the exact same way in this area.


http://www.jeffsrv-7a.com/EMPENNAGE/04-01-29.htm


Jeff

Greg, I read the same thing in the -8 plans. I figured it had something to do with trim tab clearance, but now that I have the empennage done I can't see any reason for countersinking. E-705 and E-606PP are pretty thin as it is. The 470 would make more sense here. It might be worth asking Vans.

Truely odd. I noticed the same thing. I thought about it for a bit and figured that there couldn't be any interference problems in the rib area, so I went ahead and dimpled them instead, with the flush face on e-606pp. But after seeing it all assembled and having more time to think about it, a 470 would have worked just fine there.

And another tip, since I just finished this part. When machine countersinking the top side of e-606pp, don't do the last 4 holes on the narrow end. Dimple them instead, look at the plans carefully and you'll see why. No big deal if they're countersunk, but dimpling is definitely better there.

zsadecki said:

And another tip, since I just finished this part. When machine countersinking the top side of e-606pp, don't do the last 4 holes on the narrow end. Dimple them instead, look at the plans carefully and you'll see why. No big deal if they're countersunk, but dimpling is definitely better there.

Click to expand...

Gee, thanks Zach. I already countersunk them all yesterday. I wish you would have told me a day earlier! (or maybe I shoulda' posted a day earlier).

Greg
San Diego

I just called Van's this AM - dimpling E-606PP and E-705 is fine. The reason for not using 470 rivets here is that the kit DOESN't contains 3/32" 470 rivets! Thanks for all of the advice.
Greg
San Diego