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Breaking Male Dimple Dies

Jamie

Jamie

Well Known Member
Fellow Forum Users:

I'm now well into my wings on my -7A and last night was dimpling the bottom skins in my c-frame tool. About half-way through the first skin, the #40 dimple die broke!!! I wouldn't really be that concerned about it but this is the third one that I've had break (one was a tank die that I had borrowed from a friend). I can't understand what I'm doing wrong.

When I'm dimpling, before striking the c-frame I always gently press down to bring the male/female dies into alignment, then I release and press down again to ensure that they are still aligned.

I'm dimpling with usually two blows with the rubber mallot and I'm making the dimple at the same 'crispness' as my pneumatic squeezer.

Are any other builders having the same problem?

Oh Yeah, I got my dies from Cleaveland.

Thanks,
Jamie
 
Breaking dimple dies

Don't worry, I've already broken two male dice. This is normal.
On the bright side, you get all those extra female dice that you can grind into special shapes for tight areas.

I buy my tools from Brown Tool, so I don't think the supplier makes a difference.

For new builders, I'd recommend buying three sets (or two extra male dice) right up front.

Vern Little '9A
 
I haven't had any trouble with my Cleaveland dimple dies and I'm part way through the fuselage. I'd check to make sure the top and bottom plunger on the C-frame are lined up. Your routine with the C-frame sounds like the same thing I do. I also make sure I don't have any side load on the skin I'm dimpling, like pushing sideways on the skin.
 
...what he said!

I am done with the emp and no broken dies yet.

I think you may have an alignment problem.

Have you checked for that?

:confused: CJ
 
I'm almost done with my -6A and have never broken a die. As others have said, make sure you C-Frame is aligned properly. Variance there will break things.
 
Breaking dies

Jamie said:
Are any other builders having the same problem?

Oh Yeah, I got my dies from Cleaveland.
Click to expand...

Well, first, who's C-Frame are you using?

I was using an Avery C-Frame and Cleveland dies and was breaking them frequently also. After about 3 of them, I started talking with Mike at Cleveland. He said that the Cleveland dies are tighter tollerance than Avery to make the dimples crisper and figures some mis alingment with the Avery unit caused the breaking. So I got some Avery dies, same problem. I then returned the Avery c-frame and got the cleveland one. Broke some more dies. Then got a new Cleveland c-frame from Mike. That finally solved the problem and I used the last die for the entire wings and fuselage to finish out the project.

So, from all that, I seem to have learned that it's critical that the welds on the c-frame are perfectly true and the dies come thogether perfectly. No amount of visual inspeciton seems to detect it, just the indication of breaking dies.
 
shop practice

I hold the female die against the skin, partially engaged with the male die, before hitting the arbor. This minimizes die breakage due to any misalignment between the two centers on the C-frame. Cleaveland all around.

Steve
90979
 
FYI, I'm using an Avery's C-frame and dies from US Tool. I'm just starting on the fuselage and have yet to break a die.

One thing I am doing is using the male die on top and female on the bottom. Like Steve, I hold the male die in the hole and try to hit it only once with a hard plastic hammer.

What type of hammer are the rest of you using and do you have the male die on the top or bottom?
 
I usually try to have the female die on the bottom to avoid scratching the skin underneath. However, there are times when I've had to use the mail die on the bottom and it's been fine.

At the beginning of this project, I was using a black soft rubber mallet. It was obvious after a few sessions that it wasn't going to last long. I bought an orange, hard plastic hammer from Home Depot that sounds like it is filled with lead shot. That thing has worked great.

One other thing I always do with the C-frame is use it straight on the concrete floor. I used to use it on the bench, but I get a much better dimple with less effort and noise on the floor. It's just not as comfortable.

Next time (if there is a next time) I'll get a QB. But if I didn't get a QB, I'd get the DRDT-2. It wasn't available when I started this project.

Dave
 
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