SonexBuilders.net

Hi

Does anyone have the text of what Sonex Aircraft wrote about the new rivets?

I save a lot of emails from the Yahoo list, and apparently this one is not one of them.

I tried searching there but....well.....not so much luck. I even tried an advanced search...

I just need the text they wrote so I know what to do when I begin riveting my wings on Wednesday.

Thanks and Merry Christmas to all!


Robbie
Sonex 1517

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http://groups.yahoo.com/group/onexplans/message/1315
Cheers for the season.

Thanks!


Robbie
Sonex 1517

Sent from my iPad using Tapatalk HD

Has anyone had problems with the new style rivets recently?

I used these when I riveted my wing ribs to the spar and had one problem where a mandrel broke proud - I blame that one on the riveter. Me. I had pulled it by hand, not with the pneumatic riveter, and used a jig as I could not get the nose of the hand puller into the space. Not exactly a typical pull.

From reading the Yahoo list it does indeed appear there are valid concerns, but some of the posts mentioned psi ranges way above what I was told to use and have used with success. I expect some real challenges.

Tomorrow morning I start my final riveting of the left wing and have been looking over the rivets I got from Sonex with my wing sub kit in fall 2011. After digging through my bags of CCP-42 and CCP-44 it appears I have a mix of the round and flat head mandrels. Most of the -44 are flat, but the -42 are a complete mix. All my -46 appear to be round.

I had been having great luck using my Harbor Freight pneumatic rivet gun at about 37 psi, and plan on doing this again for the wing skins. Obviously I will use the round heads first until I run out.

I will update this with the results and hopefully some photos.

If anyone has recent experience I would really appreciate their input.


Robbie
Sonex 1517

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Robbie, all I can tell you is that I only had problems with the CCP42's.I used about 35lbs pressure and had approximately one in 10 break proud .After talking with Kerry ,I took his advice and drilled 031 first then 030 and never had another mandrel break proud(Apparently it gives you a true round hole with a tight tolerance from what I understood) but that is a lot of extra work so I am going to accept the Sonex offer and replace my remaining CCP 42's with their new stock ......though I might try turning the pressure down even lower and squeezing a couple of times to see if that works first.

Thanks Mike!


Robbie
Sonex 1517

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Even the old rivets werent immune from issues. I used the old type round mandrel rivets and had 2 problems.

Some, not many of the CCP 44 rivets had a chamfer under the head and wouldnt allow the rivet to sit flat. This was only about 1 in 40 or so. Just needed to have a good look and make sure the rivet was sitting flush before pulling the trigger.

The bigger problem I had was with the stems on the CCP 46s. About 1 in 6 of those would break prematurely and needed to be drilled out :cry: Breaking mostly before the mandrel had even started to enter the rivet. Obviously a problem with the stems on that batch.

I just finished a 6 hour riveting session, and completed the lower left wing. Tomorrow I will do the upper skins.

I took some notes.

I used CCP-44 rivets with chisel mandrel heads, CCC-42 flush rivets with chisel mandrel heads, and CCP-42 with round mandrel heads. All of them came from Sonex Aircraft as part of my wing sub kit about a year ago.

First, when I riveted the wing skins to the main spar using CCP-44 rivets with chisel heads, I found that using 35 psi and 6 short pulls per rivet worked perfectly. Not one single problem all the way across the spar.

And then came the fun.

For the leading edge CCC-42 rivets, I first tried 6 pulls at 35 psi and every one broke proud. I tried 3 pulls at the same psi and they still broke proud, bit not as badly. Eventually I settled on 2 long slow pulls or a single slow pull. About half of those left a very slight mandrel stem, the rest were good.

Using a dremel and grinding disc worked, but wow is that nerve racking to use on flush rivets adjacent to the wing skins. Only one tiny mark on the skin. Whew. But I didn't like all the grind marks on the flush rivets. Oh well.

Finally, I had CCP-42 with the round mandrel head, Every one of them came out perfect.

My experience only - your mileage may vary....


Robbie
Sonex 1517

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Short follow up.

Much better luck with the CCC-42 flush rivets using low pressure and pulling the Harbor Freight rivet gun half a squeeze instead of all the way. A lot less rivets broke proud today, but I still have some clean up to do with a grinder.

For anyone not familiar, attached is a couple of photos comparing the rivets - chisel style and round. Chisel style on left.


Robbie
Sonex 1517

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Just a quick note, for any interested parties, I have been using bremick in Australia for the ccp 42 and 44 rivets and to date after 400 rivets I have only had 3 break proud all the rest are perfect.
From what I can see they don't make the countersunk rivets though so will need to source elsewhere.

Cheers