SonexBuilders.net

I'm trying to figure out the best practice for dimpling my leading edge skins; I've read through every previous thread on this and contacted Sonex.

Basically, I goofed up and drilled the first five rows of the fwd skin (top) to #30, and drilled the remaining holes to #32. I have the Sonex simple dimple die. Sonex says it's alright to go ahead with the #30 holes but to go easy on the dimpling. On some practice holes, I'm really not happy with how much the dimple enlarges the hole. It seems like the rivet is really loose.

I'm wondering if anyone has any thoughts on this. I was considering ordering the expensive dimple dies from Cleveland - does anyone know if they limit the stretch of the hole any better than the SDD? I'm leaning towards trying this but wondering if anyone has any experience or better ideas. Thanks.

I have the good dimple dies. Actually I have two sets since my overzealous teenager broke my first set. I bought 2 in case of a repeat performance. How he broke the first one I have no idea. You will also need a C frame dimpling tool. It goes pretty fast.
https://youtu.be/hdVYxRO9QU8
I agree with Sonex - don't stress over it.

Thanks Bryan - Did you find that they did a good job of not overstretching the hole? If so, I'll order up a set from Cleveland.

Mike,
Seemed ok to me. I drilled all mine to #31, as I could not get clecoes in a #32 hole. They all did seem slightly ​looser than normal before I set them. Afterwards, they were fine. The dimpled parts give you a lot of extra shear strength. I have dimpled some #30 holes and they turned out fine too.

This may be out of date, but the dimple die set I got from Sonex about 7 or 8 years ago looked to be designed to make a much steeper and deeper dimple than necessary and thus over stretched the hole. I made my own (on a small, 110 year old lathe) that worked much better. If interested, PM me with your e-mail address and I will send .pdf drawing of both the Sonex die as received, to compare to yours, and the one I made.

David A.

I have built 2 RV-6's and 2 RV-7's and an RV-8 over the last 30 years. I bought the "C frame" and dimple dies from Bob Avery in 1988 and still use them today building my Onex. I use the C frame lots of times for RIVETING both flush and dome head rivets and not just for dimpling, wouldn't be with out it. All the 1/8" flush rivets on the RV's were drilled #30 in the early days and now these days they have went to #31. Remember this.....it's just an airplane.....it's not the space shuttle, it will be fine with the #30 holes.......and yes, a #32 hole is too tight for the cleco.

When I started the Onex (my first Sonex experience) I bought the special dimples from Mike at Cleveland. I found they are ok but nothing special..... when I look at the finished product I can't say they do any better........sorry Cleveland....that's my opinion.

The Sonex "simple dimple dies" are the same as the ones I bought from Avery Tools back in 1989 and also still use today.....I also bought the 3/32" version as well. I like them for doing the curved area of the forward section of the leading edge. You can use your C frame for that but will need a helper to keep the skin nice and flat and 90 degrees to the dimple die.

Hope that helps you out Mike L.

Gordon......Onex....Hummel 2400

Thanks everyone. I wanted to post an update in case anyone can use this info later. I am definitely guilty of overthinking many things on my airplane, but I'm glad I took the time to go with the Cleaveland dies. Here's what I found experimenting with some scrap:

Sonex simple dimple die: When used to dimple a #30 hole, it really stretched it. I could dimple it "lightly", but then the dimple was subpar and the hole was still loose. Putting in a proper dimple left a hole that was really way too big for the rivet. It does a much better job on a #32 hole, but still stretches it some.

Cleaveland die: Makes a beautiful dimple in a #30 hole with very little enlargement. The pilot on the dimple does not fit through a #32 but you can coax it through with the rivet squeezer. Overall, this made the best dimples.

The Cleaveland die is expensive at $39 but worth it in my opinion. If I could do all over, I would just get the DieNQ from Cleaveland (works on a #40 hole, specifically made for Sonex/Panther aircraft); expensive, but would save some time and make the best dimples. I may still do this on the other side.

Hi all ,
Yes ive mentioned the cleveland DIENQ dies a few times in different threads. #40 hole & dimple . Nice tight fight for ss 1/8 rivets. If u drilled larger holes and used other dimple dies and the holes are too large for 1/8 rivets , u may want to think about 5/32 rivets. Have fun!

WaiexN143NM
Michael

GordonTurner wrote:http://www.cleavelandtool.com/mobile/Dimple-Die-Set-for-1_8-Adel-N-or-Q-40-Pilot/productinfo/DIENQ/#.WiQIeWJOlR4

Expensive but worth it .