carrollcw

carrollcw

Well Known Member
So, I am assembling the horizontal stab for a -7. I am to the point where it is time to rivet the skin to the ribs. When I went to Cleco the skin to one of the ribs, I noticed the Cleco would not grab the rib! I checked the rest of the ribs, and 4 of them will not hold the Cleco! The holes are not large enough for the next bit size (so I know I didn't drill them wrong) but they are clearly too big for the Cleco and rivet! Also, I dimpled all the ribs at the same time, so its not like the dimpler was set wrong.

So, what do I do? I could Cleco from the rib to the skin (since the skin will hold a Cleco) and go ahead and rivet. Or, I can drill and dimple up one size rivet, but that will be a major PITA!!!

So, 2 questions:

1) What should I do?
2) How did this happen? Did I get some ribs that were predrilled too big? It makes no sense!!!

Thanks!
Clark
 
My first thought is it could be your Clecos. There was another thread recently where several builders were complaining about inferior Clecos not holding just as you describe. Try switching your Clecos around or maybe even borrow Clecos from another builder. Hope you find a simple fix.
 
Pictures?

Some pictures might help. How do the rivets appear to fit in the holes? Have you tried to set any? I'm wondering if your clecos are defective.

Tom
 
just a thought, but did you maybe open up the skin a little too much to dimple, and maybe this is just too much spring back pressure of the skin for the cleco to grab hold, I think mine was like this?
 
I was using a pneumatic squeezer with the same dies and setting for all the ribs. As to the rivets, you can definitely tell there is more wiggle room compared to the standard rivets that I have set. Clecos worked fine before dimpling. I am thinking redrilling to next size is overkill. Leaning towards installing clecos from inside and making it work, but waiting for more responses!
 
Cleco little pieces of aluminum properly drilled #40 to back up enlarged holes. Rivet them and forget them. Use proper technique on the next batch.
 
I'm betting on the clecos also....

I must have ordered the 40 size clecos in two different sets or something because mine are distinctly different. You can hold them up and see the tiny ones that only have a small curve in the tangs versus the better ones that have a larger curve. I have mine seperated into two bins, the small ones work ok on metal that hasn't been dimpled but don't work at all afterward....

Good Luck!
 
Are you positive you used the right die set for the dimples? If drilled right and dimpled with the right die set, looks like about all it could point to is clecos IMHO.
 
normal

It is probably normal after dimpling in the really thin skin. You will find that along in the build when you have thicker skins the problem will go away.

bird
 
Isn't Friendswood near Houston? I'm sure there are several RV builders near you. Check the RV White pages and contact an experienced builder to come over and offèr an opinion. Even a phone conversation may help you.
P.S. make sure your pneumatic squeezer isn't affecting your die/hole alignment during it's action.
 
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Hey Clark - you're welcome to come by tomorrow evening if you have a chance and try any of our variety of Clecos to see if by chance that's the problem. Just give a call. Of course, I know you may be on a trip or occupied - whenever is convenient, give a call if you dont' solve it.

Paul
 
This is pretty common for me; out of over 1000 clecos, I have maybe 50 that don't work well with dimpled holes. Sometimes I find that turning a cleco 90 degrees works, as if the hole were oval shaped slightly. Dimpling does enlarge a hole slightly, so if you match-drill and then deburr too aggressively and then dimple too aggressively you might see this more often than you like. But you don't need to replace the part; at worst you might want to go up a half length on the rivets if the extra expansion is making the shop heads too thin.
 
It's the Clecoes

I have my #40 clecoes divided into two groups and color coded. One group will not hold dimpled holes, the other won't go into unreamed holes on new parts. I use each group as appropriate. I live in Clear Lake, contact me anytime.
 
for future work

consider match drilling with a #41 bit, or better yet use a #41 reamer. I made this chang after noticing that dimpling stretched the hole larger than necessary. I used a 1/8" bit or reamer on the -4 dimpled holes.
 
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Thanks everyone for all the help. I am glad to hear it was not an irreversible error!

I like Patrick's idea of just stepping the rivet length up a half size to compensate for the gap, so I think I will do that.

I did more searching and it seems this is a frequent problem with dimpled holes. I am going to make a bunch of the #40 washers to help out with this in the future! Could also buy a different brand of Clecos, but making washers will be a lot cheaper!
 
Vlad said:
Cleco little pieces of aluminum properly drilled #40 to back up enlarged holes. Rivet them and forget them. Use proper technique on the next batch.
Click to expand...

I agree with Vlad, I had a terrible dimple problem on one of the nose ribs where the whole was all crapped up, I just took a small thing piece of aluminum I want to say almost 3/4 X 3/4 put and drilled a #40 hole, deburred it, dimpled, taped it up in there so it would stay while riveting.... I went from a 3.5 to a 4 rivet, set it with the gun and bar, and then took the tape off.

Looked like it pulled it up pretty well and I set it and forget it!
:D
 
No need to panic ...

My experience with this was the same. The lesser quality clecos often do not hold once the holes have been dimpled. Held fine after drilling to size, but wouldn't hold after dimpling. As soon as I tried one of the better-quality clecos, they held fine. (I seem to recall from the other thread that the Kwik-locs are the better ones. In my case they were the shiniest ones and easy to spot.)
 
Enlarged holes

I can't help but wonder what role the dies play in this scenerio. There has been much discussion in other threads regarding clecos. I have clecos of many brands purchased both new and used here on VAF. I have never run into this situation.

I thought about dimpling the wing understructure with my tank dies. I chose not to based on the fact that the hole was much larger when dimpled with the tank dies. I preferred the smaller holes of the standard dies.

We are all using dies from different manufacturers and the die may play a major role in the dimpled hole diameter.
 
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