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-   -   dimple comparison (https://vansairforce.net/community/showthread.php?t=113098)

aturner 06-02-2014 05:56 AM

Make the countersink deep enough to properly accept the dimple. Most figure put proper countersink depth via trial and error, but here is another approach.
http://www.vansairforce.com/communit...288#post472288

Tom023 06-02-2014 10:04 AM

Quote:

Originally Posted by Tom023 (Post 881847)
I'm still trying to decide the future of the SS dies; I like the way they nest, but I think they are headed for retirement as well.

After running some more test pieces and having a tech couselor take a look at the dimples and rivets (just as part of an overall inspection, not just because of any concern), I've decided to continue on with the SS dies. I like how the pieces nest and I will just fall on the side of a longer rivet vs. a shorter one if it comes to that.

Tom Martin 06-02-2014 10:32 AM

As a follow up to this discussion I wanted to look at the final product. I really do not care how nicely the parts nest before riveting but what the final product will look like. Both the Cleveland and Avery dies were what they call spring back dimple dies.
I took two pieces of .025 metal and drilled them all at the same way, they were all dimpled with a C frame.
I used standard Avery dies, Standard Cleveland dies and a standard cleveland die with a Sub Surface die on the lower sheet.

Before riveting the Cleveland dimple with the Subsurface dimple did in fact nest together better then the Avery dies, or the Cleveland dies.
In this picture the left one on your screen is the Cleveland with the Sub Surface die
The centre picture is the standard Cleveland dies
The right one on your screen is the standard Avery dies
There was some warpage during the cutting process but the one on the left did "nest" together better. The hole of the Sub Surface die was visually larger, similar to what was found in my original post on this thread.



Then I riveted the parts using a squeezer and set the heads all the same. The part was cut and the surface buffed.
My apologies for the orientation of the picture
The top picture is the Avery dies.
The middle picture are the Cleveland dies
The bottom picture is the Cleveland die on top and the Cleveland Sub Surface die on the bottom.
Note that all three test pieces are nested firmly together. For overall appearance my preference would be the Avery dimples
I draw your attention to this bottom picture, note the small gap between the top and bottom sheet, next to the rivet. I believe that using the slightly larger Subsurface die on the lower sheet means that there is not enough "material" on the top sheet, with the smaller Cleveland dimple, to fill the hole between the parts and the rivet.
Over the years I have purchased tools from both Cleveland and Avery, they are both excellent suppliers and I have no affiliation with either supplier.
Based on my experiences with the Sub Surface dies I can not recommend their use.


Jake14 06-02-2014 11:45 AM

Tom, Verrrrry interesting, great work.

I would really like to see similar x-section comparisons on a dimpled surface nested into a countersunk surface with various countersink diameters/depths (see my previous post on this thread)

az_gila 06-03-2014 09:43 AM

Quote:

Originally Posted by Tom Martin (Post 885006)
....

Since the deeper dimple dies were originally sold as "tank rib dies" - your picture shows that the gap created is just right for creating a sort of proseal "o-ring" in the middle of a tank riveted joint.

David Paule 06-03-2014 10:16 AM

The tank dies, designed for that job, are different yet.

Dave

Tom Martin 06-03-2014 11:15 AM

Yes the dies that I purchased were not the tank dies and were not advertised for that purpose, at least according to the website.http://www.cleavelandtool.com/Substr.../#.U43vgV63A-Y

wirejock 06-03-2014 12:43 PM

Testing
 
Interesting. Thanks for posting it.
I don't use a SS die unless the dimple going into it is a tank die dimple. I used them on the tank and areas with three layers where the top layer is standard die, middle layer tank die and bottom SS die. The wing walk was a good example and they seemed to nest together very well but I have not cut samples to test. It would be interesting to see. For two layers, I dimple the bottom layer with tank dies. All are Cleveland.


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