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Skin dimpling question

Palamedes

Palamedes

Well Known Member
Hey guys,

I'm finally to 6-3 Step 6 which has me dimpling the exterior skin of the vertical stab. Exciting times.

I am looking at my dimple die kit and I see the correct male dimple, but there are two female 3/32 ones.

One is thin and a little taller, one is fat and a little squatter. Since I have others that have done this I'm guessing there is a reason.

Is this because one is 100? and one is 110? or something? looking at them with the naked eye its hard for me to tell.. but I *think*(tm) the fat one is slightly shallower (100??) than the thinner one.

Again, wild guess. Am I close? Should I be using the fat one?

Thanks
 
Palamedes said:
Hey guys,

I'm finally to 6-3 Step 6 which has me dimpling the exterior skin of the vertical stab. Exciting times.

I am looking at my dimple die kit and I see the correct male dimple, but there are two female 3/32 ones.

One is thin and a little taller, one is fat and a little squatter. Since I have others that have done this I'm guessing there is a reason.

Is this because one is 100° and one is 110° or something? looking at them with the naked eye its hard for me to tell.. but I *think*(tm) the fat one is slightly shallower (100°?) than the thinner one.

Again, wild guess. Am I close? Should I be using the fat one?

Thanks
Click to expand...

Some have a label stamped on the side. Reply with the markings and I'm sure one of the experts can decipher. Cleveland dies are marked.
Tank dies have "T"
Substructure "SS"
You may also have a close quarter die.
Most dies are 1/2" diameter. Some taller than others depending on manufacturer.
My standard 3/32" dies are not as tall as my Cleveland dies.
I would expect odd angle dies to be marked.
 
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Smaller die

The smaller die is a close quarters female die. The part number (14870) is listed in the kit you reference.
 
Ah sure enough.

Okay so not tank or substructure dies then.

So my next question;

Are Tank and Substructure dies needed/a good idea, or.. feh.. not really?
 
Dies

Palamedes said:
Ah sure enough.

Okay so not tank or substructure dies then.

So my next question;

Are Tank and Substructure dies needed/a good idea, or.. feh.. not really?
Click to expand...

That's almost as debatable as the primer wars. :eek:
Tons of RVs built with just standard dies.
Personally, I use the tank and substructure dies.:D
 
I also used tank and substructure dies on the advice of Van's tech support. He also advised me to paint them different colors, because mismatched 3/32" dies will go together...once. "Ask me how I know."

I followed his advice, but I can't tell you how much better it is than just using standard dies. In the end, I decided they were pretty inexpensive so I might as well follow Van's advice.
 
Palamedes said:
So my next question;

Are Tank and Substructure dies needed/a good idea, or.. feh.. not really?
Click to expand...

They are not listed in the suggested tools lists that are included in the plans of newer kits like the RV-10, 12, and 14. That means the people :rolleyes: involved in writing plans and manuals at Van's say they are not needed (and I happen to know they are not used during the construction of any of the prototypes or demonstrators).
 
Palamedes said:
Ah sure enough.

Okay so not tank or substructure dies then.

So my next question;

Are Tank and Substructure dies needed/a good idea, or.. feh.. not really?
Click to expand...

Just my opinion, but I began with using the specialized dies and felt that the rivet holes were enlarged a bit too much. Been using the standard dies ever since (including tanks) and have been more than happy with my results.
 
I ordered a set of substructure dies a long time ago, and never used them until recently. I used them to dimple the fuselage J-channel skin stiffeners. Everything fits together just fine, of course. What is interesting, though, is that I have had at least half a dozen clecos pop out of their holes while I was riveting the next hole over. That NEVER happened until I started using the substructure dies.

Mine are for sale, cheap, if you want a set. I won't be using them again.
 
I use them religiously (tank and SS), especially if you have a triple stack to work on. I'm pretty sure that only Cleavland makes them (you could make your own), so clearly, there are award winning homebuilts are constructed without them. I like the way the skins nest using them. YMMV.

If youre popping clecos, its because you drilled your hole too large before using the die. I use a slightly undersized drill and allow the nose of the die to enlarge it (debur the hole prior). Never had a cleco pop.
 
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Clekos

DaleB said:
I ordered a set of substructure dies a long time ago, and never used them until recently. I used them to dimple the fuselage J-channel skin stiffeners. Everything fits together just fine, of course. What is interesting, though, is that I have had at least half a dozen clecos pop out of their holes while I was riveting the next hole over. That NEVER happened until I started using the substructure dies.

Mine are for sale, cheap, if you want a set. I won't be using them again.
Click to expand...

Dale
Don't sell them. It's not the dies. I also use them for multiple stacks.
Look at the clekos. All clekos are not equal. Clekolock brand have a thinner center pin. They tend to pop out of dimpled holes. Wedgelock brand are better IMHO. The center pin is thicker. Never had one pop out. I marked all my Clekolock. They work fine for initial assembly but after dimpling, I use the Wedgelocks.
On the dies, for all but the tank, I use Standard on skin, Tank on the middle layer, Substructure on the bottom layer. Or Tank on the bottom if two parts.
For the tanks, I used Tank on skin and Substructure under. The parts nest nicely.
 
maniago said:
If youre popping clecos, its because you drilled your hole too large before using the die.
Click to expand...
Yes, obviously if I use the same #40 drill bits and reamer I've used all along and something else happens when use the SS dies, I must have been doing it wrong all along. :rolleyes:
wirejock said:
Dale
Don't sell them. It's not the dies. I also use them for multiple stacks.
Look at the clekos. All clekos are not equal. Clekolock brand have a thinner center pin. They tend to pop out of dimpled holes. Wedgelock brand are better IMHO. The center pin is thicker. Never had one pop out. I marked all my Clekolock. They work fine for initial assembly but after dimpling, I use the Wedgelocks.
Click to expand...
Considering that I can see no real difference in the fit & finish with and without the SS dies, and the fact that thousands of RVs have been built without them, I've decided I'm not going to substantially change how I'm building (and sort through 400 clecos) to accommodate someone's idea of a better mousetrap. The substructure dies may have their place, but that place is not in my tool chest. I can either buy different size drills and reamers to use them, or pass them along to someone else who wants to use them... and my results will be the same. It's a pretty easy choice for me.

For you guys who choose to use them, good for you. Build on.
 
My decision to discontinue their use was based on the holes looking unusually large, followed by my "scientific" c-frame/micrometer test:D. 100 ways to skin a cat. Some swear by one technique, others curse it. Definitely try things for yourself before putting the kibosh on something:

BC073CD4-B86E-432B-B2C9-0BB99C6EB99B.jpg
 
maniago said:
If youre popping clecos, its because you drilled your hole too large before using the die. I use a slightly undersized drill and allow the nose of the die to enlarge it (debur the hole prior). Never had a cleco pop.
Click to expand...

I suggest caution to builders using this technique.
As has been mentioned before, the normal dimpling process with standard dimple dies already stretches the material and enlarges the hole diameter.
Ramming a die pilot through an undersized hole amplifies this even more.
Yes, deburring helps but is no guarantee of no cracks in this scenario.
As an example of how sensitive it can be, Vans has now established a standard process of pre-punching all screw holes slightly under sized and then specifying they be final drilled and then deburred on both sides before dimpling. The reason is because of the variability of surface finish on the interior of the hole. In some instances, even if you carefully deburred both sides, radial cracks would still occur when it was dimpled. Final drilling to clean-up the hole finish, deburring and then dimpling greatly reduces the likely-hood of cracks.
So my point is.... Inducing other elements into a process, can in some instances cause unforeseen results.
I have always said, and will continue to say, forcing a dimple die pilot through a hole is a bad idea.
If someone wants to use a process of a smaller diam. hole, my recommendation would be to get a custom set of dimple dies that have a proper diam. pilot.

BTW, this is the same reason I discourage dimpling pre-punched holes without final drilling (except on the RV-12 and RV-14, where the holes are final punched the appropriate diam.).
 
rvbuilder2002 said:
I suggest caution to builders using this technique.
As has been mentioned before, the normal dimpling process with standard dimple dies already stretches the material and enlarges the hole diameter.
Ramming a die pilot through an undersized hole amplifies this even more.
Click to expand...

Did I say ram it in the hole? Please. I said slightly undersize. The hole is going to stretch no matter what so do some test pieces first and verify.

I think the cleco difference is a good take however. I haven't noticed that with any of the brands I have, but I'll look for it if I start popping them.
 
maniago said:
Did I say ram it in the hole? Please. I said slightly undersize. The hole is going to stretch no matter what so do some test pieces first and verify.

I think the cleco difference is a good take however. I haven't noticed that with any of the brands I have, but I'll look for it if I start popping them.
Click to expand...

Not good choice of word for the difference of a few thousandths, but the point is the same, it is stretching the hole even more than if the holes was proper size.
The point being that the pilot has to forced into the hole. Not a good thing based on my experience., and why at Van's we specifically recommend not ever doing so.
 
Hey fellas, I am traveling now and with the iPad I am limited a bit. Could someone please post links to a couple of my prior threads on this issue. They are in the RV14 forum, dimple comparison, and, the perfect rivet.
Both are relevant to this discussion

Tom Martin
 
rvbuilder2002 said:
....and why at Van's we specifically recommend not ever doing so.
Click to expand...

That's right! And its a good recommendation, because you can't control someone elses interpretation of "slightly", so I have no problem with the factory KISS answer. None at all.

But I have, oh IDK, a couple of thousand substructure dimples that I've done, all without cracks under 10x mag, so it works for me. Note: I do this on SS dies only, not on regular dies. Is there a difference, again, IDK, because I find the shop heads sit nice on the regular stretched holes - and not so nice on normal drilled SS died holes.

There is margin in building; but yes, not everywhere, not all the time, and not for everyone.
 
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