Dimpling problem

[psalter]

It is certainly preferred to use the smallest hole that the rivet will still drop into easily. Rivets like bolts have tolerances they are made to. Solids range from .124 to .128 so a #30 fits all of them. Cant find the tolerances on the bsc/bsp rivets, just says .125 diameter, and recommends final hole size of .129 to .133. Dimpling usually increases the hole diameter slightly, and that depends on the dies used. So, it might be that while the rivets you have now fit, a later batch may not, and would require a larger hole.

Chris, I do use the dies with the male on the bottom, but still had the debris issue.

[Sacpilot]

One way to prevent debris is to have the male die on the bottom.

[GlenNJ]

Paul, as usual more good advice. I haven't had a problem yet with the male and female dies sticking together. I'll try to keep them clean, and hope this doesn't happen. I'm having a problems when I drill a #31 hole, and the male die gets stuck in the metal I'm dimpling(while using the Cleaveland DIECS4-4 dimple die set, 1/8" x 120 degrees). It wasn't bad on the thinner metals (up to .032), The thicker the metal, the harder it is to pull apart. When I tried to dimple the .040 hinges, it actually got stuck in the metal, and it took minutes to pull the die out (I tried this 10 times, and finally gave up). I wasn't aware that the 1/8" drill bit is between the #31 and #30 sizes. I drilled a 1/8" hole (in the .040 hinge), and the die fit perfectly. I dimpled, and the rivet seemed to fit perfectly. I tried to push a #30 drill bit through the 1/8" dimpled hold, and I could only get it through if I pushed it hard. It almost seems like the 1/8" drill bit is the perfect bit for the dies and the rivets. This brings up a question. I understand why you drill a #30 hole for a solid rivet. As you said before, the solid rivet will expand to fill the hole when driven. You also said pulled rivets don't expand as much as a solid rivet when driven. If a 1/8" hole allows a part to be dimpled, and the rivet drops in place, why up drill to the slightly larger #30 hole? I checked with Avery, The Yard and Aircraft Spruce. They all sell 1/8" jobber drill bits (for some reason Cleaveland doesn't). Wouldn't it be better to use a slightly tighter fitting 1/8" hole instead of a #30 one (as long as the rivet will drop in the hole)?

Glen

[GlenNJ]

Let me correct myself with the DIENQ part number. When you order this dimple die set from Cleaveland tools, that's the part number on their web site. The part number on the package the die set comes in says NQDIE. DIENQ and NQDIE are the same thing.

[Tony Spicer]

Can anyone tell me who makes a good #30 x 120 degree dimple die, that won't have the male end get stuck every time you squeeze a dimple?

Thanks,
Glen

Bob Avery does: http://www.averytools.com/prodinfo.asp?number=14877
!0,000 Panther dimples and never an issue.

Tony

[psalter]

Glen,

One thing we found after using the DIENQ for a while was that very small debris from the dimpling process would start to fill the female portion of the die. After enough buildup, the male end would slightly mushroom at the end and stick in the female die. To fix it, I chucked the male portion in a lathe, and with sandpaper/file I cleaned up the mushroomed portion, until it fit nicely in the female portion (make sure to clean out any debris from the female portion). You should be able to clean up the male portion by hand, but the lathe was faster/easier.

To stop the problem, we started to clean the debris out of the female die after every 15 to 20 holes or so.

You might be having the same problem with the 1/8" dies.

If a #30 bit works best with those dies, then go ahead and use it, there is only 0.008" difference between them. As has been stated some testing with dimpling goes a long way to work out problems (there are so many die combinations, that it is impossible for us to test every one. For solid rivets, the #30 is the preferred size, we found that sometimes, the hole after dimpling could be too large for pulled rivets. Another bit size to try is a standard 1/8" as it is in between a #30 and #31.

The manual was written before the DIENQ dies came out, that is a perfectly acceptable means of dimpling, and we at SPA have started to use them as our primary dimpling dies.

[GlenNJ]

I'm having a problem when I try to dimple for flush riveting. I'm using Cleaveland, 120 degree dimples dies. When I use the Cleaveland NQDIE dies (drill a #40 hole, dimple, up-drill to #30), I have no problems. If I drill a #31 hole and use the Cleaveland DIECS40-4 dies (1/8" x 120 degree), the male end of the die gets stuck in the dimpled part every time. It can take me several minutes to free the die (I have to be careful not to damage the part). I guess Cleaveland machines their dies to ultra close tolerances. I want to do as the manual says, and drill a #31 hole (instead of a #30), before I dimple. Can anyone tell me who makes a good #30 x 120 degree dimple die, that won't have the male end get stuck every time you squeeze a dimple?

Thanks,
Glen