$100 for a old 1/2 HP punch press

Not if you set it up properly.

Some have a stripper arm, some dont.

In the absence of pictures were all guessing what this press is all about.

I have a 25ton power press and this uses a 3hp motor. so a 1/2 hp motor will drive a 4 ton press, or thereabouts. Now theres a lot to learn all about press work. apart from the safety angle.

you need to know what the punch clearances are for various thicknesses of material, also what depth through the die the punch goes. this has to be adjustable to suit the material. also theres a nack in using these machines by hand. were not talking about automated strip fed power presses with sequential tool and die sets.

this sounds like a simple foot pedal operated one shot press for small components. You need to be taught how to use it so that your safe and can produce consistent blanks from sheet thats hand fed. This latter task needs planning so that each blank is close to the previous one so you can strip the sheet off the punch with a small twisting action. I do it all the time with the 6 ton press I have as well. the same principles apply if your blanking with a fly press. you only need guards if you employ someone. officially. I wouldn let any one else use it anyway.

hope this helps you decide wether you want to learn some new skills.

.
Reply to
Ted Frater
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But you STILL shut off the motor and/or block the punch with a big chunk of timber or steel when putting your hands in there. And use tongs or a stick to change the blanks with the power on. Old control systems often have failure modes that can cause it to cycle.

You have to treat it as if it's out to get you.

Even with a proper two-hand-no-block safety system on the cycle trigger switch you still don't let ANYONE operate it who does not respect the safety concerns. Or you'll get your ass sued off when an employee loses a body part.

And the best idiots get help in breaking all the rules - they'll stick a hand in to hold the die in position (with a stick that in retrospect was about an inch too short) and have someone else two-hand cycle the punch...

This is why you don't see many antique machines in modern production shops - safety issues that can't easily be retrofitted away.

This is why I was so piss poor slow doing old fashioned Letterpress Printing (where you change the paper by hand) - I wouldn't try feeding the press fast enough to let it go into continuous feed unless I had the speed turned way down. And having the speed fast, tripping it by pedal once the paper was in position, and waiting after the cycle to make sure it didn't double-trip was no better.

But I can still count to ten without blank spots. This is good. ;-)

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Reply to
Bruce L. Bergman

Yeah......."sudden" is an even better discription of little presses. That speed makes them far more dangerous then larger presses with longer cycle times.....which are still plenty dangerous if you don't follow safety protocols at ALL TIMES. Dave

Reply to
dav1936531

Ayup. Lots of old punch operators called Lefty...

Reply to
Gunner Asch

Interesting discussion.

So, a good start would be a safety conversion from pedal to two switch operation, right?

i still ambidextrous

Reply to
Ignoramus3778

Two key switches 10' apart ala missile silo...

Reply to
Pete C.

If it helps to hear another voice say the same thing..

Find a certified, experienced and trustworthy tool and die maker to SHOW you how to operate your press correctly. After four thousand hours working on mechanical and hydraulic presses up to 2500 tons capacity, I was still very careful EVERY time.

With mechanical presses (yours), you get to jam it precisely ONCE. When you do, something WILL break. People have been crushed by massive flywheels and gears coming off the presses due to a smash. Don't be fooled by the size of your machine. Find the formulas and calculate the amount of energy that flywheel has stored. Your mushy body doesn't stand a chance. That press will be *the* most dangerous tool in your shop.

Regards,

Robin

Reply to
Robin S.

Thanks to all. I brought the press home (rather, it is in my trailer).

Some notes:

- It was VERY painful to maneuver my trailer in almost total darkness (no streetlights on that street), into a narrow driveway at the dead end of a street.

The flashing light that I made for it, saved my ass:

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- The press was made by BLISS (no idea if it is good or bad).

- I want to clean it up and get into nice shape, maybe even change a motor since I have a few spare motors.

- I want to try it out carefully (ie, keep hands in my pocket while operating the foot pedal).

- I have not yet decided whether the press is worth the space that it would take. My guess is that the answer is no.

- To my uneducated mind, it seems that most proper uses of this press revolve around leather, not metal.

i
Reply to
Ignoramus3778

I fully agree. these presses are like any moving machinery, they will catch you out if you dont respect them. I guess im probably the only self emplyed drop stamp owner operator on this newsgroup, and I made very sure the previous owner of of my 1880 drop hammer /mint showed me how to use it properly. After I had rebuilt it asa fully working machine, the first thing I did was to put some 4 by 2 in where the die went and drop it to splinters till I had the hang of the lift/ drop/ rebound/park, control. If you use them as they are meant to be , you should be allright.

Reply to
Ted Frater

Yes.

its simple enough to cobble up a pair of NO momentary switches and use them to fire off a solenoid to trip the dog clutch.

And far far safer.

Though to be fair...I work on these a couple times a month and only see a few women (usual operators) with missing fingers or divits. But then..they often quit right after an accident.

An interesting side note about presses. Lots of the old mechanical dog clutch ones still in operation and being bought and sold.

However..and this may give you something to consider...most are bought and sold for cash, with no receipts/bills of sale tendered. And often the buyer has to give the seller a signed statement that the press is being bought as Scrap and will not be operated, only destroyed.

In our litigious society...this is about the only way one can protect himself when selling a mechanical press. And Ive brokered 15-20 in the last 5 yrs. ALL..ALL...ALL being cash sales between good sized companies.

Ive been told that 60% of the price of any new press, is insurance.

Few machine tool dealers will admit to being able to supply a punch press. However they nearly all know someone who has one.....

Gunner

Reply to
Gunner Asch

Good advise.

Gunner

Reply to
Gunner Asch

Very old..very good.

Gunner

Reply to
Gunner Asch

Only part of the palm could be saved I can't remember if she lost the thumb, but she did lose all four fingers.. She was 16, and in high school when it happened. Somehow, she was able to adapt, and laugh at what happened. Her parents owned a business that made replacement parts for antique cars. I don't remember if it was the 10 ton, or one of their larger presses they used to make fenders, it was about 25 years ago. I do remember that she had a wicked sense of humor, and loved to make people laugh. :)

Reply to
Michael A. Terrell

OK, good point on insurance and cash/disclaimer on sales. I finally got it into my garage and will clean it up. It seems to work fine. Weighs about 300+ lbs.

i
Reply to
Ignoramus3778

======= Until it doubles because of a stuck/sticky clutch.

The only truly safe setup is pull-backs or a sliding door or sweep. These just sprain or break the arm/hand rather than cut it off.

Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.

Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.

Reply to
F. George McDuffee

Oh, absolutely. And you want to put guards around anything that moves just so someone doesn't get 'brain fade' and put their hand in where it shouldn't go - only takes a fraction of a second of inattention to make a batch of hamburger out of a hand.

The term you want is a "Two hand no tie-down" safety circuit, where you have to push two buttons roughly at the same time. And the press won't reset if one or both buttons is held down, as would happen if someone deliberately jammed one of the buttons to get out of pressing it each time.

Clippard makes one that's 100% pneumatic (logic control valves, like air relays) if the machine is all air powered and air operated, and you don't want to run electricity to it just for the controls.

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Reply to
Bruce L. Bergman

The good old american iron is an excellent candidate to build DIY iron worker. I did a conversion of an old bliss to operate with a hydraylic cylinder for a client that manufactured wroth iron fences. He was able to punch 1" square holes in

1/4" plate and channel iron in 5 seconds. If you need a short throat iron worker you can build one at reasonable cost using a scrap yard punch press and some hydraulics.

Best Regards Tom.

Reply to
azotic

Hell..thats a tiny one.

Gunner

Reply to
Gunner Asch

Even the pull backs are not perfect.

Back in the 60's I was working as a tool & die maker for a large maker of automotive gauges (S-W) in Chicago. An operator lost both hands due to mis-applied pull backs. The die he was running was in a long stroke press, and the bushings in the punch holder completely left the leader pins in the die shoe, when the press was at the top of it's stroke. Well the cables on the pull backs somehow got wrapped around the bushings. And when the press was tripped, the operators hands were pulled into the die.

The die came to the tool room for clean up. No volunteers, the foreman did the clean up.

John Normile

Reply to
Camperken

Heck, we couldn't give a 60T one away so we broke it down to base castings and then got the scrap man to come get it.

Wes

Reply to
Wes

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