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  #1  
Old 11-16-2013, 05:16 PM
Jasonm Jasonm is offline
 
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Default Rivet quality issue

Hi all,
Before we start riveting the VS and rudder we started some test riveting on our C-frame and hydro-pneumatic hand squeezer and issues quickly arose with the results. All the rivets squeezed seem to "push" or lay over to one side. We cannot get a rivet to squeeze perfectly for anything. We've tried adjusting the air pressure, travel length of the squeezer, different dimple dies, and using different backing plates. Nothing will produce an acceptable result. Take a look at these pictures and help me figure out what's going on. All the rivets are 426 3-3. After match drilling using a #40 bit the hole was .101-.103 but after dimpling the holes opened up to .106-.110! The pictures seem to indicate the dimple hole is too big.


This one was set in the C-frame by itself and squeezed.


Here's our C-Frame


Take a look at the two on the right. They're "pushed" over.


Another one "pushed over"


Last one

Are we being unreasonable or is there something wrong here?

Thanks all.

Last edited by Jasonm : 11-16-2013 at 05:53 PM.
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  #2  
Old 11-16-2013, 05:32 PM
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az_gila az_gila is offline
 
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Smile

They seem to work as links to pages - in the same order as the OP -

http://www.flickr.com/photos/108923716@N06/10894143286/

http://www.flickr.com/photos/108923716@N06/10894103735/

http://www.flickr.com/photos/108923716@N06/10894100055/

http://www.flickr.com/photos/108923716@N06/10894402075/

http://www.flickr.com/photos/108923716@N06/10894257544/
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  #3  
Old 11-16-2013, 05:32 PM
BillL BillL is offline
 
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Default

The real experts will weigh in here, but that stand alone rivet did not look straight. If I put one in my hand or pneumatic squeeze, they compress straight.

I would say something is wrong. Something is wobbling or deflecting or not square.

Oh - your pictures don't show. Check in preview before posting and you should be able to see them. Sorry, I don't know how to fix them either.

Good luck in your investigation.
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  #4  
Old 11-16-2013, 05:47 PM
Jasonm Jasonm is offline
 
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Default

I updated the image host and they work now.
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  #5  
Old 11-16-2013, 05:58 PM
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bret bret is offline
 
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That is one fancy C frame, I would check for any measurable deflection or any longitudinally movement while squeezing the rivet. And check for Parallel die surfaces while under load. I built my own frame and bought the head unit, but had to go back and reenforce my frame with more material to minimize load induce deflection.
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  #6  
Old 11-16-2013, 06:02 PM
AK-Models AK-Models is offline
 
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Default several reasons

Rivets will do that if:
1. pneumatic squeezer is not perfectly vertical to the rivet itself.
2. rivet is too long for the material
3. rivet will not form correctly by itself, needs material to form to
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  #7  
Old 11-16-2013, 06:03 PM
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Mike S Mike S is offline
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Default

To my way of thinking, this is a dimpling tool, and not a riveting tool.



Where did you get the pneumatic setup??? I like it.
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  #8  
Old 11-16-2013, 06:04 PM
Jasonm Jasonm is offline
 
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Thanks Bret. Deflection on the frame is less than 1/16" under full load. We've checked to make sure the head is square and perpendicular to the bottom plate. What makes me think it's the hole diameter after dimpling is that if we hand squeeze a 426 the result is the same.
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  #9  
Old 11-16-2013, 06:06 PM
Jasonm Jasonm is offline
 
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Quote:
Where did you get the pneumatic setup??? I like it.
Thanks Mike. The head came from Numatx and my father built the rest.

It does make one heck of a dimplier though!

Last edited by Jasonm : 11-16-2013 at 06:09 PM.
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  #10  
Old 11-16-2013, 06:07 PM
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blueflyer blueflyer is offline
 
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Quote:
Originally Posted by Mike S View Post
To my way of thinking, this is a dimpling tool, and not a riveting tool.



Where did you get the pneumatic setup??? I like it.
Yep, I have tried to use my DRDT a time or two for riveting and they turn out just like that. For a test, try a hand squeezer and see if they don't turn out as they should.

I never bothered to try and figure out the way to make my DRDT smash a good looking rivet.
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