Elevator countersinking question

The manual on page 6-10 states to countersink for the E-705 to E-606PP and also in the next step countersink E-705 attach holes on the forward face of E-702 (where the elevator horn covers them). In both cases, I can't see why Vans have suggested countersinking rather than dimpling? Any ideas? I countersuck the E-702 on the right elevator but the material is quite thin and I wasn't sure it was the udeal way. Did it anyway 'cos the manual said so, but am still wondering for the left elevator. If you can shed light on this I'd sure appreciate it...

Jeff...

Just doing the elevators. Have to confess I just looked at the drawings here, saw they were 426 rivets, and dimpled 705/9 and the spar. 705/9 need a dimple grip type tool since the angle is such you won't get a squeezer in there.

I can only agree with your thoughts that you should not be c/sinking sheet this thin...

Andy
just joined forum - RV-8 QB on way, half way thru' Emp, UK

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Kiwi Jeff,
I have just finished a -7, but I had the same queries
Regarding 606PP to E-705 I have just looked in my Manual to find I had written a ? next to paragraph you refer to.
I am sure that, as I saw no sense in it, particularly as besides requiring a countersink, it said that the countersink face could go EITHER on 606PP or E-705, so I DIMPLED it.

I am vague about E-705 to E-702, but I think I dimpled it.

What I did find is the same countersinking query popping up throughout the manual for inexplicable reason. In the end I had the feeling that different sections were written by different blokes and that one of them was obsessed with countersinking.

But the MISTAKE I made was to Dimple E-606PP where the piano hinge attaches. I then tried to De-dimple it with the squeezer and it took up a curve due to the stretching of the metal. Be careful. I had to order an new one.

Hope that helps,
Aussie Pete.

Thanks guys. In the end I elected to dimple and it worked out just fine. I did csk the top of the 606PP though. The elevator itself is doen now and I need to do the trim tab.

Trim Tab

Jeff,
i made a mess of the first trim tab as I didn't use a strong enough 'G' clamp to hold the bending blocks. They moved inside the tab skin and the bend was off line.
Clamp it tight.
Pete.

Cheers Pete. I used [old] double-sided tape to hold the blocks in place when I did the elevator; took me ages to get the damn stuff off again. At least it didn't move though!