Compressor for 20 ton press

[Dan C]

I visited Kevin Potter's workshop the other day, and I was blown away by the quality of his work. His presses are just awesome.

 

When we discussed whether to use a 20 ton air/hydraulic jack or his custom built 20 ton hydraulic system, he suggested that a jack would be no less expensive after you figured in the cost of a $1000-$1200 5hp 80 gallon compressor.

 

I asked him if he really felt that a big expensive shop compressor was necessary for operating that jack, and he was pretty insistent that 20 ton Jacks consume a lot of air and require a large tank.

 

Granted, when he runs a jack off his compressor, it runs damn fast and doesn't slow down during a heat. So I'm not disagreeing that bigger can be better. And I know that Kevin knows a helluva lot more than I do. But I'm wondering if a smaller compressor might still work.

 

Does anyone here have experience running a 20 ton air/hydraulic jack off a smaller compressor like a 5hp 30 gallon?

 

Any advice would be greatly appreciated.

[Dan C]

By the way, I'm posting this topic because I'm building a medium sized forge press based on the now-common "mini forge press" design, and I'm trying to decide between all the options for operating it. I'll post pictures when I'm done.

[Jan Ysselstein]

Dan

I love those mini-presses, they are very well built by most of the makers. I have seen them work forging steel, but I do not think they are particularly good for that application...they are very slow. That slowness is ideal for some applications, say pressing sheet metal into rubber platens , and especially clamping at a continuous pressure as might be needed in some lamination with adhesives ( micarta for example). I would listen to Kevin and go the hydraulic pump route.

 

Jan

[Dan C]

Jan, thank you for your advice. I have to say I'm surprised by it, though. I see videos on YouTube of those presses, and they look great. Like this one.

 

http://m.youtube.com/watch?v=x9O6YplCdRo

 

Is this not as effective as it appears? I'll admit I'm new to this. What am I missing? Is it the small surface area of his dies? Is it the softness of the metal he's playing with? What size compressor would be required to operate that effectively?

[Dan C]

Here is Kevin's press operating with a 20 ton jack and his 5hp 80 gallon compressor. This looks a very effective setup.

 

[Jan Ysselstein]

Dan,

That is a nice little press , but it is moving at 1stroke per 3 seconds..and the metal is cooling rapidly. So why not press at about 1 to 1.5 strokes per second ( or 3 to 5 times as fast ) with a slightly wider die and a shallow deformation. If you get into laminated blades or any blades where the surface will reveal the forging history...you may want a lot of control during forging.

You may want to go with a jack as a starter project. Good luck.

Jan

[Dan C]

Jan,

 

Thank you again for the input. I think see your point. Less effective press means you need smaller surface area dies to move the steel. Smaller dies mean more uneven distribution of pressure. In forge-welded pieces the pattern you develop will not be pretty and even, but will reveal areas of greater and lesser compression.

 

I hadn't thought of that, but it makes sense.

[Dan C]

So, I'm still left with my original question. Will a 5hp 30 gallon compressor operate a 20 ton jack as effectively as we see in those videos, or would you need a big 80 gallon shop compressor?

[Bret]

The question of your compressor keeping up is a matter of CFM more than anything. I used to use a setup similar to these in the past with a 5hp 30 and my compressor would only kick on every 3rd or 4th heat. You should be fine. But a hydraulic set up is the way to go. The speed and surface area that can be worked makes them WAY faster, and more consistant. We build tools to make our job faster, and easier. Going full hydraulic is not that much more expensive, and worth every penny. Just my 2 cents

[Richard Furrer]

Generally you will be happier with shop air for tools as well as a dedicated Hydraulic power pack

BUT

if you to end up with air anyway then I suggest going that route first and add the electric/hydraulic power pack later.

 

I'm not happy with a 150 ton unit running at 1" second...but I do weird things. On occasion infinite tonnage and infinite speed would be about right, but you need to start somewhere.

Ric

[Dan C]

The question of your compressor keeping up is a matter of CFM more than anything.

Thanks SO much for your input, Bret. I REALLY appreciate it. What does CFM mean?

 

 

I used to use a setup similar to these in the past with a 5hp 30 and my compressor would only kick on every 3rd or 4th heat. You should be fine.

This is good to hear.

 

But a hydraulic set up is the way to go. The speed and surface area that can be worked makes them WAY faster, and more consistant. We build tools to make our job faster, and easier. Going full hydraulic is not that much more expensive, and worth every penny. Just my 2 cents

Thanks for this advice, too. Seems that people who know what they're talking about all say this.

[hansjohannsen]

Somewhere back in past posts is my mini press I built have had no problem running it off a pancake compressor. Gotta start somewhere and that setup saved me a lot of time.

[Dan C]

Ric, I hear you. I wish money weren't a factor. I'd buy me some awesome toys. Infinite speed and tonnage sounds sweet. Reality sucks sometimes.

[Dan C]

Somewhere back in past posts is my mini press I built have had no problem running it off a pancake compressor. Gotta start somewhere and that setup saved me a lot of time.

This is good to hear.

[dragoncutlery]

cfm cubic feet per minute if you have a huge tank with a low cfm compressor head it will take forever to fill and your out put air will or can fluctuate high cfms and a small thank would be better and high cfms with a large tank even better

[Dan C]

Ahhhh. Got it. Thaks, Brandon.