JerryBaumchen 1,048
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erdnarob 1
Hello Jerry, pchapman just asked me the same questions.
I designed my swaging press according a picture seen from Ron Dione's one. When Ron saw it he told me that mine was nicer.
1) since I figured out that the top horizontal bar was going to resist to the flexion (6 tons+) I made sure to make it from 2" thick tool steel. On Ron Dione picture you could see that the top horizontal bar was bent.
2) I use the same set of dies (top and bottom) for both pin and ball. Both dies are identical with a 1/2" long groove very slightly convex since when swaging the squeeze on the cable is more progessive. On destructive testing the cable always seems to break at the very location where it is first squeezed which is a weak point. Having a slightly convex groove avoid partially to have a weak point. Here is pictures of the press top and the rip cord testing device (300 lbs for 3 seconds) I designed and made. It uses the lever principle.
I designed my swaging press according a picture seen from Ron Dione's one. When Ron saw it he told me that mine was nicer.
1) since I figured out that the top horizontal bar was going to resist to the flexion (6 tons+) I made sure to make it from 2" thick tool steel. On Ron Dione picture you could see that the top horizontal bar was bent.
2) I use the same set of dies (top and bottom) for both pin and ball. Both dies are identical with a 1/2" long groove very slightly convex since when swaging the squeeze on the cable is more progessive. On destructive testing the cable always seems to break at the very location where it is first squeezed which is a weak point. Having a slightly convex groove avoid partially to have a weak point. Here is pictures of the press top and the rip cord testing device (300 lbs for 3 seconds) I designed and made. It uses the lever principle.
Learn from others mistakes, you will never live long enough to make them all.
JerryBaumchen 1,048
Hi Andre,
QuoteOn destructive testing the cable always seems to break at the very location where it is first squeezed which is a weak point.
Do you mean at the location of the ripcord pin? This, to me, is a very unusual location for the point of failure. Under theoritical considerations, it should fail at the ball end. But, that is the theory.
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Thanks for the photos. Always nice to find out what other people out there are doing.
My ripcord tester was built by some jumper in Southern California years ago ( I do not remember his name; Bob something I think ). I got it from Ray Ferrell many years ago ( it is same kind as the one that Kelly Farrington of VSE has ). It uses a torque wrench to determine the load(s) on the cable.
Have fun in DeLand,
JerryBaumchen
PS) Best part of the internet is the exchange of information.
Is that a single cavity die or does it have dies for both the ripcord & the ball seperately?
Back in the '60's Ron Dionne ( one of your countrymen ) began making dies using a single cavity press. He built them to press the pin on and just used the same die to press the ball on. The end result ( the ball ) looked a little 'different' but they worked ( and probably are still working; I think Al MacDonald uses one of Ron's die sets ).
Here is a photo of the die set the I designed and had made, it uses two cavities. I can easily get to the TSO req'ment of 600 lbs; and I do occasionally get a sample tested by an outside entity just to eliminate any bias as I do have my own ripcord tester.
I find this interesting: At the end we had a destructive testing and never the pin or ball slipped at all. The cable gave up at tension of 800 lbs or more.
In theory the pin is good for 100% of the cable & the ball is good for 80% of the cable. To find the 'real' info on this stuff get out of the ripcord industry and go to the wire rope industry.
All good stuff though,
JerryBaumchen
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