Dimple Dies

[BillL]

Early in my building I noted the same gap and cheated by spinning a deburring tip in there lightly a couple of times and the rivets were perfectly flush. I used Avery dies.

The only time you will notice is before paint or during polishing the skin. The little gaps will wick in black goo in the polishing process and it must come out or leave streaks in when buffed.

[RV3Kev]

Check that the dies are not the Tank or Substructure dyes that are made by Cleaveland. This are oversized and may create the problem that you are seing

[MS1095]

Originally Posted by Captain Avgas

What type of device are you using to form the dimples. When I see dimples like yours it?s usually the device that?s the problem rather than the dimple dies.

I am also curious as to what you are using? Good chance it's the tool.

[Jarrett]

So I went ahead and dimpled my rudder skins with the Brown dies and I am very happy with how they turned out! When rivets are placed in everything fits together nice and snug. I did get the chance to do one dimple with the Cleaveland dies and this is how it turned out.
https://photos.app.goo.gl/TSEC7d3zgoA3bjKdA
On the left is the Cleaveland die and on the right is the Brown die. For these dimples I used the DRDT-2, and the results are same as when I dimple with my TACTO hand squeezer. Moving forward I will be using the brown dies on the skins and Cleaveland dies on ribs (substructure). I'm not exactly sure why the Cleaveland dies are producing this gap... Some builders have experienced these results in the past, so maybe it's just how they're manufactured? In the end, once it's all painted I won't notice these gaps on the vertical stabilizer, so I think I'll have to relax (I've started dreaming about the build ) Thanks everyone!

[BrianDC]

It almost looks like you have a tank die vs the standard die. Give a shout to Cleaveland tool and they may be able to help you out.
Regardless, I'm sure the brown dimples will work just fine for you.

[birddog486]

I see you linked my question so my .02 is this. The cleveland dies have a slightly different angle/shape to them which creates this gap/appearance which could be considered a con.

The pro side to this is when comparing two large sheets that are side by side, one using cleveland dies and another brand the skin deformation around the holes is much lower using the cleveland dies.

I used the DRDT-2 during my build but also tried the C-Frame and had almost the same results with the cleveland dies.

My plan was always to polish the plane so I was shooting for smooth skins without deformation around the rivets. If your planning to paint that may not be an issue for you.

I'd suggest on the thicker skins, setup the DRDT with a fairly tight preload and give each hole a double pull on the handle.

Good luck on the build, I've got 65hrs on mine and she hasn't fallen out of the sky yet...

Walking around at Oshkosh the past few years and looking at other RV's its a 50-50 mix with planes having the gap and not.

[JDA_BTR]

I've used only the Cleaveland dies and I have no gaps. I don't see on all your samples the "coin" impression around the dimple. When I dimple I get a definite impression of the die, using a DRTD2. Is it possible the height of the brown die is slightly higher so you are getting more driving pressure with it?

Are you dimpling with the plastic on? I don't.

Also it is possible that the method for dimpling the rib isn't getting a deep enough dimple there. It is possible to setup the squeezer so it isn't generating enough pressure, esp if it is pneumatic. It will act right but takes more fiddling than the DRDT2.

[vlittle]

Originally Posted by JDA_BTR

I've used only the Cleaveland dies and I have no gaps. I don't see on all your samples the "coin" impression around the dimple. When I dimple I get a definite impression of the die, using a DRTD2. Is it possible the height of the brown die is slightly higher so you are getting more driving pressure with it?

Are you dimpling with the plastic on? I don't.

Also it is possible that the method for dimpling the rib isn't getting a deep enough dimple there. It is possible to setup the squeezer so it isn't generating enough pressure, esp if it is pneumatic. It will act right but takes more fiddling than the DRDT2.

+++!

I've been invited to 'review' several new builder's workmanship over the years. The #1 issue I find is improper dimpling. I get explanations from builders, such as ?I used my expensive ?hydro-dynamic electoflux confabulator?, so they must be right!?

Wrong.

Dimples must be crisp. Under dimpling produces waviness in the skin and the rivets improperly nest. If you look down a row of dimples, the light reflection in the skin must be flat.

When I demonstrate how to adjust their dimpler, or how hard to whack with a c-frame dimpler, the light bulb comes on. It's about seeing the halo around the dimples... No halo means it's a problem.

The difference between manufacturer's dimple dies has not been an issue for me, but they could be contributing.

Try again. Whack harder or adjust your dimpler in or out. Get the halos and you should be good.

V

[wirejock]

Originally Posted by vlittle

+++!

I've been invited to 'review' several new builder's workmanship over the years. The #1 issue I find is improper dimpling. I get explanations from builders, such as “I used my expensive “hydro-dynamic electoflux confabulator”, so they must be right!”

Wrong.

Dimples must be crisp. Under dimpling produces waviness in the skin and the rivets improperly nest. If you look down a row of dimples, the light reflection in the skin must be flat.

When I demonstrate how to adjust their dimpler, or how hard to whack with a c-frame dimpler, the light bulb comes on. It's about seeing the halo around the dimples... No halo means it's a problem.

The difference between manufacturer's dimple dies has not been an issue for me, but they could be contributing.

Try again. Whack harder or adjust your dimpler in or out. Get the halos and you should be good.

V

Finally. Thank you for bringing this up.
I get asked as well and underdimpling is often the issue. If someone asks, I help.
If they don't, oh well. I've seen entire airplanes underdimpled.
Burnish doughnut is good. Distorted pillow is not.

[mturnerb]

Originally Posted by vlittle

+++!

I've been invited to 'review' several new builder's workmanship over the years. The #1 issue I find is improper dimpling. I get explanations from builders, such as ?I used my expensive ?hydro-dynamic electoflux confabulator?, so they must be right!?

Wrong.

Dimples must be crisp. Under dimpling produces waviness in the skin and the rivets improperly nest. If you look down a row of dimples, the light reflection in the skin must be flat.

When I demonstrate how to adjust their dimpler, or how hard to whack with a c-frame dimpler, the light bulb comes on. It's about seeing the halo around the dimples... No halo means it's a problem.

The difference between manufacturer's dimple dies has not been an issue for me, but they could be contributing.

Try again. Whack harder or adjust your dimpler in or out. Get the halos and you should be good.

V

On the DRDT-2 you feel a definite end-point, slight "pop" perhaps when the dimple is fully formed. If you don't feel that, it's usually not a great dimple - easy to fix though, just hit it again to feel the end point.