Press forming basics

[Halberds]

This is turning into an interesting thread for me.

I have a 10 ton shop press and has only been used for bearings and gunsmith.
I also have a big-ass arbour press that used to demold tin/lead alloy castings.
I have not found any more uses for it.

When I was intrested in power dishing I made a few of these:



It was a joint effort of 3 disciplines, called Variable Rate Air Hammer VRAH.
Most of the parts, less the cast iron cylinder, came from McMaster Carr.

The control unit was made by Chupa.
It's a multi-vibrator flip-flop oscillator with a 3 speed control.
He designed the circuit boards and stuffed them himself.
The control worked beautifully with McMasters valve and others 1.5" cast iron cylinder.

http://home.armourarchive.org/members/halberds/vrah.avi

However a commercial attempt to produce these failed catastrophically.

Hal

[Minotaur]

Yeah hal is right. The way the valve works, when you open a port, it will engage the check valve. The check valve will keep the return closed till it reaches its set psi (in this case 2000) once it reaches that psi it will reopen the return. The valve is spring centered so it will return to center on its own when you release it, when its centered the oil just flows back under 0 psi. The only thing is when the ports close at 2000 psi they will remain at that psi until released. So the system could be off and read 0 psi but the jack and the line (to it), could still be at 2000psi. Hope that helps.

Also I got all my parts from http://www.surpluscenter.com . Almost anything you could need from 1 to 250 tons or more when it comes to hydraulics there is no limit. At the time I think I got all my parts for less then 800(I am sure it would be more now) and all of it was made in the usa except the cylinder that was made in cnd. I got my setup because I also like to forge things and bottle jacks are a little slow for that.

If your just doing basic dishing you dont need any of that fancy stuff. All you need to get started is a bottlejack, frame, rounded ball hitch, some way to get that ball hitch on to your jack, a wood dish(its soft and will let the metal conform to die just as if you were working by hand) and an arbor plate.

[Aaron]

Bump, because this just became more interesting after talking with my brother iin law.

[The Iron Dwarf]

have a little press that I bend 30mm square steel with ( 1 3/16" ), have dished 12mm plate ( 1/2" ) without it even noticing, it is powered and has a 3hp motor.
have just got a 200mm ( 8" ) steel hemisphere to make a top tool with