billy's plans built sonex 1735

[Rynoth]

What # drill bit for leading edge skin have you used pre- dimpling. Thanx billy

I used standard 1/8", which basically falls between a #30 and #31.

[Area 51%]

It says specifically on page W07 not to use a #30. The holes can end up too big after the dimpling causing proud rivet mandrels and the possibility of the rivet pulling completely through. It calls for either a 31 or 32.

Seems to me I remember someone offering a dimple die set that has a 3/32 pilot for the 1/8 rivets. Then you can open up the holes to 1/8in after the process.

[WesRagle]

It says specifically on page W07 not to use a #30. The holes can end up too big after the dimpling causing proud rivet mandrels and the possibility of the rivet pulling completely through. It calls for either a 31 or 32.

Seems to me I remember someone offering a dimple die set that has a 3/32 pilot for the 1/8 rivets. Then you can open up the holes to 1/8in after the process.

Hi Randy,

I think this is what you are thinking of. Works just fine as far as I can see.



BTW, back in the day I drilled a sonex leading edge to #30 and then dimpled. Of course, while riveting the mandrels started pulling through. Another Tony S. tip was to use a hand puller and "pump" the rivet as it was being pulled. Apparently the pumping work hardens the mandrel and caused it to break before pulling through. It was a pain but very few mandrels pulled through using that method.

For the second wing I drilled to #32. I also chucked up my #30 dimple die in a drill press and "machined" it down to #32 with the edge of a file. Besides permanent damage to my #30 die, that worked just fine.



Wes

[Rofomoto]

Thanx guys.

[DCASonex]

This is from 7 years ago, but then the Sonex supplied dimple dies where made at a much steeper angle than necessary for the angle of the rivet heads, and that was major contributor to expanding the holes over-sized. Do not know what they are supplying today, but worth taking a look at. That die set had a 100 degree seat and an 80 degree nose. A 3/32" die set from Avery tool was a much shallower angle so made my own 1/8" die set, Used a 118 degree drill bit for the seat in the female half, with the nose part turned to 115 degrees. Did not open the holes anywhere near as much. Used a #32 drill bit for nice tight final fit, and selected suitable mandrel (nail) for the new die set to fit that # 32 hole..

David A.

[Rofomoto]

I have a 120 deg 1/8” die set from Cleveland tools. I did some practice dimples through #32 holes. It seems to work pushing through that size hole. Still thinking

[Rofomoto]

Done dimples and deburring. Ready to close up. Not going to have lights but thinking of running wire. What size and number of wire should I run? Also how did you secure it? Thanx billy

[GordonTurner]

Maybe larger than you will need.....I ran a twisted pair of 18GA to each wingtip for landing light (+ and -), plus a shielded 3-conductor 20GA for:

NAV
STROBE
STROBE SYNC
shield for ground.

Gordon

[Rofomoto]

Maybe larger than you will need.....I ran a twisted pair of 18GA to each wingtip for landing light (+ and -), plus a shielded 3-conductor 20GA for:

NAV
STROBE
STROBE SYNC
shield for ground.

Gordon

Thanx Gordon. How and where did you route them

[GordonTurner]

In conduit through the larger of the nose rib lightning holes, held with adel clamps on home made brackets.