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  #11  
Old 07-26-2011, 07:36 PM
cameron cameron is offline
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If you put rubber or urethane in a pocket, it has to be smaller in area than the pocket to allow it to expand sideways, otherwise it can't compress in thickness. The effect would be about the same as solid contact between the die stem and the holder. This is for solid rubber, of course, not foam rubber.

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  #12  
Old 07-26-2011, 08:25 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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Quote:
Originally Posted by Resto Rod Race View Post
I have been wondering about this and been looking through some older posts, I have a P5 pullmax and have been looking at buying the eckold style shrinker dies, but from whats been said the rpm of the machine is to fast and it wont have enough ompf if i get a variable speed unit for it, and i might have clearance issues?
Thanks
Adam
Based on my experience I wouldn't recommend it Adam. Even Clay Cook (PROLINE), who sells the adapters, admits they don't work very well.
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  #13  
Old 09-01-2011, 11:40 PM
Peter Miles Peter Miles is offline
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With regards to potential "give" in the Pullmaxes, the P-7 and above machines plus the P-21, P-201 lines are belt-driven instead of the direct-coupled motors on most of the smaller machines.

However, I wouldn't want to count on very much give in those V-belt or vari-speed drive units.
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  #14  
Old 11-29-2011, 02:48 AM
robert robert is offline
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Quote:
Originally Posted by route56wingnut View Post
The major difference between these machines is that Eckolds are designed with the ability to "over hit".That is that there are multiple contact points that are made of a non metalic material that wont ruin the machine(as I would suspect may happen over time) with a recip machine.As has been mentioned elsewhere the speed of the stroke is realy critical with this type of dye as it has to have time to recover.That is it has to go to its base position so as to fully hold the metal and then either S or S.The design of an Eckold die is completely different and to make these dies work correctly you would unfotunatly have to then Overhit with a machine not designed to do so.Dan
i have a 1956 bottomstroker eckold i didnt take it apart completly
but for what i could see i dont think the bottomstrokers have this overhit
system

in my mind its only a big flywheel with a crank and rod and an exentric to the end connected to the foot pedal
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  #15  
Old 11-29-2011, 08:15 AM
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Kerry Pinkerton Kerry Pinkerton is offline
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Robert, Even though mine is a top stroke machine, I THINK that your machine is similar to my Piccolo in it's mechanism. If you look VERY carefully at this photo:

b 002.jpg

You can see the rubber at the top of the walking beam. It's hard to make out. Way up forward you will see vertical pieces of metal on the sides.
Between them and the end of the beam are rubber pieces. These isolate the beam from the quill and offer some 'give' when the tooling comes together in addition to the rubber inside the tooling itself.

If I ever have it apart again, I'll figure a way to get a better photo.
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  #16  
Old 11-29-2011, 11:51 AM
TheRodDoc TheRodDoc is offline
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There is no give to that arm connection. It Doesn't cushion anything. It gives no over hit.

All the rubber does is hold the arm up against the hardened rocker cap and hardened wear insert so there is no backlash as a pinned connection would have. They use this principle through out the machine to lessen wear and eliminate lubrication.

In this drawing 18 is the changable hardened steel cap.
21 is the replacable hardened insert. lays on arm top.

The red rubber blocks are bonded to the green metal part. When assembled the rubber is preloaded to pull the arm up tight to the rocker cap (18)

echoldarm.jpg
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  #17  
Old 11-29-2011, 03:33 PM
robert robert is offline
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kerry that rubber migth be in my machine i havent seen its iinside that deep

richard wauw you really lost me in understanding and translating but i trust your knowledge about the subject goes way beyond mine
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  #18  
Old 11-29-2011, 06:19 PM
TheRodDoc TheRodDoc is offline
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These springs in this drawing are doing what the bonded rubber would do. They keep all free play from the pivot point.

echoldarm2.jpg
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  #19  
Old 11-29-2011, 06:40 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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The definitive proof of what RodDoc is saying is this:

I put a 7" aluminum block where the tooling goes and ran the adjuster down until it touched. Once the contact was firm, the adjuster will would go no further. When the spacer was removed, the adjuster would go much further down before it ran out of adjustment.

Therefore, there is no give in the Eckold mechanism (at least not in the Piccolo. All give is in the tooling.

RodDoc is correct I was wrong.
Make a note of that.
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  #20  
Old 11-29-2011, 10:41 PM
John Buchtenkirch John Buchtenkirch is offline
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Maybe some 15 years ago I was talking to someone in technical sales at Pullmax. He told me that some flex is designed into the Pullmax frames as a safety factor for people that run the tooling too tight, that is why there are many Pullmaxes over 30 years old that are still running just fine. Around the same time I adapted Erco shrink jaws to my P21 Pullmax. Thru the years I have told people that I only consider doing so partially successful. It works well on light soft aluminum but not so well on steel. Because of Pullmax frame flex I’m always able to shrink farther with my Marchant kick shrinker. I often run my P21 with zero or even slightly less than zero clearances but nothing flexes the frame like using those shrinking jaws. Very hard on the machine, people are probably better off to stick with thumbnail shrinking dies. Several people followed my lead on this (even though I advised them against it) and admitted I was right after doing so. I can certainly see the appeal of adapting the jaws because using a kick shrinker just beats your leg or legs up. I have a 40 ton Whitney deep throat punch (runs 88 SPM) that I’d like to try to adapt the Erco jaws to some day but don’t know if I’ll ever get around to it. So many projects and less & less time every day . ~ John Buchtenkirch
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