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C-Frame Dimpler/Riveter Table with Retracting C-Frame

R

ROTARY7

Well Known Member
http://www.numatx-tools.com/index.html


Anyone looking to do some serious dimpling / riveting with a 22" reach C-Frame, may appreciate this post. See the link.

PDF Drawings for the C-Frame and Table are free. See the "DOWNLOAD" page.

The C-Frame will accept the Numatx 3060-1 standard riveter, which further accepts standard C-yokes. The C is substanially stiffer than other Frames out there and can be waterjet cut at a local steel supplier. The table is 2x4 / plywood construction, and can be altered to suit. The 22" reach C-Frame can be readily retracted when not needed, via a sub mounted shear pin.

Also, I have introduced a solenoid controlled intensifier, which can be controlled via a head mounted trigger switch, or electric foot switch.
 
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I have a 22" bench yoke for my CP-214 and it dimples perfectly...I can set 3/32 rivets with no problem. Its 1" thick 4140 steel so 1-1/2" is probably a bit overkill.
 
Not Overkill

Bob,

The plate thickness isnt overkill. It has been engineered, not purely guessed at. I can say that because if you take a look at my website, you will see the FEA results that pointed in the direction of how thick to make the C. It would have been nice to make the C from 1" thick plate as you have. However, for my 1-1/2" thick version, the tip deflection with 3K of force is still 1/8". This deflection robs from the stoke of my squeezer head, which is .5", so I was trying to minimize that. A 1" thk plate would probably deflect 50% more, or about 3/16".

You mentioned that you are setting 3/32" rivets just fine, but some might like to set 1/8" rivets, thus the need for more rigidity. The plans I offer are free, and one can make the thickness however thick one wants, although it would need to have a different connection method for the squeezer yoke if it is made thinner than 1-1/2".

One last point, is that for your CP-214, unless you are using a remote foot switch for operation (not standard when you buy one), you can only have one hand on the skin, to allow for one hand on the squeezer trigger. For my unit the foot valve is standard, meaning both hands can be holding the skin. This makes moving the skin from position to position easy.
 
Just saying mine works fine for what I do with it being 1" thick, and because its that thickness I can physically pick it up and put it away. Last year I stumbled across a CP-214 squeezer and foot pedal for $75 on ebay and the seller had no idea what it was for...so they didn't list it as an aircraft tool.
 
Sounds like you found a great deal, and I can't blame you for buying those tools at those prices. I'm in the business of making new tools, competing against the tools that were designed 50 years ago, not rounding up used tools and reselling them. If someone can find great deals as you have, I applaud them. The same holds for used engines and used aircraft for that matter.

I've posted before about the 3 lb weight advantage I have over the CP-214, and the fact that the CP types are not constant force, so I wont go into that in greater detail. My tools aren't cheap, as they aren't made in India.

I only replied in response to your statement that the giant C yoke I designed was "overkill" as you stated. I put a little bit of time into running Ansys FEA to optimize the stiffness and stresses, and I think your statement implied I might have held my thumb up to the screen.
 
C-Frame

Hi there, first time poster...but have been lurking around the site for a little while now...!!

A big thumbs up to Mark at Numatx-Tools. His HP riveting system not only looks the goods, it works exceptionally well. After purchasing, Mark followed up with a couple of emails asking how I was going with it....how's that for customer service..!!

I intended to build a DRDT dimpling frame. Mark provided his C-Frame drawings and his testing results for its stiffness. It was clear that Mark has put a bit of work into it, and on checking the numbers, he's spot on. Also, it was a little more cost effective to go with the C-frame.

Have attached a couple of photo's of the finished product, and very happy with it.

Now running out of excuses with the RV8 (std kit) build.... :)))) Looking forward to the long road ahead..

Thanks very much Mark.

Cheers
Ken Osbourne

C-Frame1.jpg
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C-Frame2.jpg
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Plate costs.

Danny,

According to my local metal supplier, Alro Steel:

http://www.alro.com/Welcome.aspx

A 4140 material 1.5" thk 30 x 18" plate will cost $390. A Hot rolled A36 plate of the same dimensions will run $283. These cost are for NEW material, that is saw cut from plate. One might be able to do better by scrounging for the plate from cutoffs at a supplier (they often sell these at deep discounts), or visiting a local scrapyard.

Or...one might reduce the thickness from 1.5" to 1", with some reduced stiffness. Another alternative is possibly three plates of .5" thickness stacked together. I am only presenting options here.

A waterjet shop I use charges $75 for setup and would likely charge another $100 for the cut based on the thickness and path length.

If you can find an EQUALLY STIFF solution for less money, I would go with it.
 
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