N

N208ET

Well Known Member
Was wondering if the 888 mid-longeron is suppose to be countersunk or the skin is suppose to be countersunk, same with the 889. I think with 889 I am suppose to countersink the bottom skin, dimple the side skin and leave the longeron untouched.

Randy
 
Randy,

As I remember, I dimpled all the skins and countersunk the longerons. In the case of the 889, where the two skins overlap, I dimpled both skins and countersunk the longeron again.
 
Bit of advice ...

Take the time to read ahead in the build instructions ... several pages if necessary. It will save time and answer a lot of questions and it will avoid making mistakes ... ask me how I know! :eek:
 
888

I think there is a couple different ways to do this, was wondering what people have done, the directions get a little hazy here. Vans told me to countersink the sandwiched skin, dimple the outer skin, and leave the longeron untouched for 889. They also said to countersink the aft side skin instead of the 887 upper longeron. I had already countersunk the longeron, so I went back in the directions thinking I had screwed up, definately not the first time. But they say to countersink the upper longeron from tip to tip per-instructions. I haven't had to countersink a skin yet, think I might countersink the lower aft skin.
 
Dimple vs C/S

Hi,

I did a search and found this thread as I have today and yesterday asked Vans the exact same question about my RV7 in three spots namely:

1. The front lower skin (772 on and RV7). I asked would it be better to dimple the top skin, cs the second and leave the longeron ountouched.#
2. The aft skin has two rows of holes where it connects to the centre section. I asked about C/S ing the forward row of holes on the sandwiched skin, leaving the underlying bulkhead alone and finally
3. The main longeron has two skins above it. Should I simply countersink the sandwiched skin and leave the whole main longeron alone.

Vans referred me to section 5, but I asked the question again, for a recommendation, and what do Vans to on these sections on there aircraft?

Others any thoughts?

Andrew Butler
RV 71700
Galway, Ireland.
 
I countersunk the longeron

After 2 calls to Vans, they recommended me to dimple the outside skin, countersink the sandwiched skin, with the longeron behind it. I practiced countersinking on a piece of .025 skin, the countersinks came out ugly, and in order to get them deep enough, the back side of the countersink was knife edge sharp, and the hole was larger than AN3. I also talked to a couple RV friends, they recommended countersinking the longeron, which is what I did. If your longeron is .063 or bigger, than countersinking for a AN3 hole should work fine. I am sure either way would work, just seemed to make more sense to me they way I ended up. I have looked through the instructions a couple times, I might be missing the step in there, but I can't find it. Anyway, build on.

Randy
 
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