Forward wing skin dimpleing

[Sonex1243]

Curious as to how everyone dimpled their forward wing skin and ribs after piloting to #40. The plans revision tells you to use a #32 pilot for dimpling, but, that size is too large to hold with a #40 and too small for the #30 cleco.

[Rynoth]

Good question. You'll want to dimple the skin and ribs separately, so you only really need to cleco #32 holes while updrilling. Dimpling opens up the holes and the copper clecoes will fit better once dimpled. I believe I was able to mash enough copper clecoes into #32 holes (with some difficulty in places) to finish the up-drilling process. Then take it apart, deburr/dimple, and it went back together with copper clecoes.

Or, you could cheat a little and use a 1/8" bit (which is somewhere between #30 and #31.) that fits the copper clecoes better.

This question makes me wonder how builders handle this issue when choosing the full dimple rivet option.

[saddler]

Cleco caps are the way to go. If you use the cleco caps on the silver 3/32 clecos they will hold in a #32 hole. I flush riveted my entire airplane and this method worked for the whole thing. Yes it is an additional expense but it works great. The grey caps are used on the 3/32 silver clecos.

[DCASonex]

About 6 years ago when i got my dimple die from Sonex, found it was much steeper angle than needed for the rivet and even if drilled to #32, rivets would not always hold, die just opened the hole too much. A 3/32" die I had from Avery Tool had much flatter angle, essentially copied that and made my own die set for the 1/8" rivets. Common 118° drill bit provided the seat in the female die, and turned male die on lathe to about 122°±, that combination worked well with #32 drill bit into which most copper (1/8") Clecos would fit. Sonex may have changed their dimple dies by now, but worth looking at what you have and comparing angle of dimple to what rivets require.

David A.

[WaiexN143NM]

Hi all ,
Here is a solution u may want to try for dimpling. Cleveland aircraft tools sells a dimple die set for 1/8 pop rivets (120 degree) . U drill with a #40 pilot hole then dimple die , the hole will be the right size for a 1/8 pop rivet. Also one note of caution is a lot of dimple dies for solid rivets is 100 degrees.
The dimple die from Cleveland tools is item # DIENQ cost $50.

WaiexN143NM
Michael RADTKE

[Sonex1243]

Great recommendations everyone, thanks!
I have been experimenting with a piece of old wing skin and it seems to be the best outcome, so far, with a lightly dimpled #40 pilot hole for the skin with a snug rivet fit. Haven't tried it on a rib yet. I tried #33, #32 and 1/8" with a light hole debur and it would open the hole up too wide for a rivet, but, I may still be doing something wrong. I tried with light pressure and the dimple hole would be out of round. I ordered another dimple die from Sonex as I used my current one recently on some .032 material for a cowling repair and might have tweaked it.

[Sonex1243]

Update- My suspicions of my current dimple die possibly being the culprit was correct. After receiving a new one, it was very obvious that the male portion of the die was not the same shape of the new one after using it on another project at work. Much better dimples with a #32 drill. Finished upsizing the forward skin and now in the process of fitting the wing tip before the tear down for the dreaded deburring.