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An oddball dimpling question

cdeerinck

cdeerinck

Well Known Member
I have the need to put two holes in my fuselage skin. To be specific, the F-820-L-1 on an RV-8.

The bolt for the holes will be an AN509-8R10, which has a 100 degree countersunk head. So I will use a #19 drill for the hole, and a #8 die for the dimple.

My problem is that the skin is installed, so I can't use my DRDT-2 to do the dimple. Further, I can't think of any way to hold the female half of the die to back up the skin.

Does anyone here know of a way to dimple a hole in-place on a skin like this?
 
Drill a 3/16" hole in a chunk of steel. A chunk that is heavy and that fits on the inside of the surface you're dimpling.

Insert the shank of the correct female dimple die into the 3/16" hole.

Attach the male dimple die to your rivet gun. Some riveting kits come with a set which is drilled to hold dimple dies. If you don't have one, make one or buy one.

Now, dimple the hole using your chunk of steel/female die and your rivet gun/male die.

Here's a store bought version of the tools you need:

https://www.aircraftspruce.com/catalog/topages/buckingblocks.php?clickkey=9213
 
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You need something like this, in an appropriate size.

DIE426CQ_lg.jpg


Put the nail and one die on one side, nail poking through the hole. Place the other die on the stem on the other side, and use a rivet puller to squeeze it.

What this is, is this product at Cleaveland.

If they don't have the size you need, they've been known to make one. Custom ones cost more, though, and take a little while - but work nicely.

Dave
 
Just today

Just used a gun and bench top dimpling bar to dimple the heater box on a RV7/9 fuse. If using a gun, turn down the air, otherwise you could be like me and break off the guide point on the dimple die. It doesnt take much to get a good dimple using a gun. This is the really old a school technique.
 
Thanks!

No only answers, but good answers, and a variety of choices!

I really appreciate you guys taking the time to help. Thank you!
 
The other thing you can do in that situation is dimple the piece using your screw, a nut, and a homemade die.

Through-drill a piece of 1/4" (or thereabouts) aluminium or steel to the hole size you want. Countersink it to make yourself a female die. Radius any sharp edges. Run your screw into the hole you want dimpled and through the tool you made. Attach a nut to the screw where it protrudes through your freshly made dimple die.

Tighten the screw/nut and that'll give you a nice dimple.
 
Kyle Boatright said:
The other thing you can do in that situation is dimple the piece using your screw, a nut, and a homemade die.

Through-drill a piece of 1/4" (or thereabouts) aluminium or steel to the hole size you want. Countersink it to make yourself a female die. Radius any sharp edges. Run your screw into the hole you want dimpled and through the tool you made. Attach a nut to the screw where it protrudes through your freshly made dimple die.

Tighten the screw/nut and that'll give you a nice dimple.
Click to expand...

I was about to type the above, with the exception of using a junk mushroom set in the rivet gun to set the dimple. You should get a more 'crisp' dimple using the gun than you can pull with the screw.

I've found the nail-pulled dies to be my 'last resort' for dimpling; the nail will break before giving a good crisp edged dimple.

Charlie
 
I reached out to Cleaveland Tool, and they sent me this link:

http://www.cleavelandtool.com/8-SCREW-DIMPLER-SET/productinfo/1026/#.XKJP9qeZNSN

I agree that the nail puller didn't give such great results, but since this one is larger, I think it will do the trick.

I was going to go with Wirejock's recommendation and make bucking bars, but I can't figure out how to put the male die into my gun. I don't have any "junk" rivet gun heads.

After I use this tool from Cleaveland, I might give it a few taps with the gun to cleanly set the dimple.
 
Chuck,

I'm in the same spot. I do have the drilled rivet set in rv7charlie's post, and just yesterday I drilled a bucking bar for the dimple die. Tried it on scrap of the same thickness (.040) and it works perfectly.

Now all I have to do is conscript a helper to crawl inside with the bucking bar. I couldn't help noticing how close we are to each other...just sayin'
 
I've used the dimpler cleavland sent you, actually have it for a #8 and #10, works well, but easy to mess up the threads on the allen bolt, probably why they give you three. ;)

cdeerinck said:
I reached out to Cleaveland Tool, and they sent me this link:

http://www.cleavelandtool.com/8-SCREW-DIMPLER-SET/productinfo/1026/#.XKJP9qeZNSN

I agree that the nail puller didn't give such great results, but since this one is larger, I think it will do the trick.

I was going to go with Wirejock's recommendation and make bucking bars, but I can't figure out how to put the male die into my gun. I don't have any "junk" rivet gun heads.

After I use this tool from Cleaveland, I might give it a few taps with the gun to cleanly set the dimple.
Click to expand...
 
rv7charlie said:
....I've found the nail-pulled dies to be my 'last resort' for dimpling; the nail will break before giving a good crisp edged dimple....
Click to expand...

Cheap nails will break.

I got a pound of hardened finishing nails from Home Depot and they rarely break. I've only used a few.

What happens is that the puller grips the nail and leaves a serrated grip indentation. After a number of dimples, the serrations no longer let the nail to slide back out of the puller and I have to work it loose. Even then, I don't bother replacing the nail. Instead, I file down the serrations and it works fine again - I only do that one time, replacing the nail afterwards. I probably get a dozen excellent dimples per nail.

Dave
 
Chuck,
I believe I used the chuck that came with my C-frame to hold the die in the gun.
It came with a short and long set that a dimple die fits into.
 
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