Drilling bottom side of leading edges

[kevinh]

To ya'll who have gone before... A quick question before I do it tonight: I've used the straps to pull the LE edge down so I can cleco to the spar and everything lined up nicely. When I go to drill bottom side of the LE ribs, do I leave the straps on as I work from spar towards nose? Thanks for any advice (so fun!)

[NWade]

Kevin -

Double-check the plans and assembly instructions, but IIRC the proper order is to ratchet the skins so you can cleco to the spar. Then you start drilling through the skins into the forward ribs, working your way from the spar forward towards the leading-edge, and from the middle of the spar outwards in both directions (towards both the wing root and the wing tip). You should cleco as you go.

Bringing the skin down to the ribs will push the skin "forward" and make the leading edge a "sharper" / tighter bend. Trying to do this with the straps still tight will cause problems, as it will prevent the skin from moving forward and re-shaping properly. Once you have securely cleco'ed the skin to the spars, you should carefully/gently remove the straps. As long as you've cleco'ed through the spar at every 2nd or 3rd hole, the force will be distributed across the spar enough that you're not in any danger of the holes elongating/tearing out. :-)

Good luck!

--Noel
Sonex #1339
Center-stick, TD, Flush pulled rivets, Acro-ailerons, Turbo AeroVee

P.S. I have tons of wing construction photos on my Sonex album here:
https://picasaweb.google.com/1039641523 ... redirect=1
[Note that the photos are in reverse order, so scrolling down takes you backwards through time]

[kevinh]

Thanks Noel - that's what I was thinking but your comments really helped!

[kevinh]

It worked! (wow the amount of spring that needed to be moved towards the front was daunting...)

[NWade]

Nicely done!
...Wait, you have a helper to drill all those wing holes? Man I'm jealous!! ;)

--Noel

[kevinh]

One more question for anyone who can help: The second row of rivet holes from the front required a lot of pressure to get the skin to fit with the rib for drilling. When I look at the wing from the side I can see some flat spots where the cleco (and eventually the rivet) is pulling the skin to the rib. I'm considering adding a .025" spacer there to make things fit better. Thoughts?

[Bryan Cotton]

Kevin,
I riveted the top first. It looks better than the bottom. I decided to get over the dimples underneath, they are not too bad.

[Darick]

Kevin, I remember adding a few spacers here and there throughout the building process, anytime there would have been an unusually big dimple. I don't remember the exact number but maybe 10 places on the wings and fuselage.

[kevinh]

Thanks guys - I think I'll do something similar.