Forging press, speed vs tons

JTknives

JTknives

Blade Heat Treating www.jarodtodd.com
Knifemaker / Craftsman / Service Provider
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Jun 11, 2006
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So with the new shop and the extra space I am strongly considering ditching my small forging press. It's been a good press and made a lot of Damascus but I out grew It many moons ago be did not have the space for the upgrade. So with that in mind I have started researching this future build. One thing my small press has taught me is speed might not be everything but it sure helps. My small press uses the harbour fright air over oil 20 ton jack and I honestly doubt it is actually 20 ton. But that being the case it seamed to move metal quite well at first but the big draw back is speed. It is slow so the dies suck the heat out quick and the press slows even more. So if I could keep the same tonnage as what I have but bump the speed up quite a bit I think it might be better then more tons and slow.

So would it be impractical to go with somthing like 15tons and shoot for as much speed as I can get. I would go with a single stage pump so I had a constant speed and no delay when the dies contact the hot steel. I would use at least a 5hp motor but not set on a RPM yet. What set me down this speed vs ton path was when I came across some posts by quick and dirty and his thoughts on forging presses. I was thinking more tons is better but his posts made me look at things differently and I can see how it could be better. My only issue on going for speed is getting into a situation where it's to fast to control accurately.
 
Discussed some builds here: http://www.bladeforums.com/threads/medium-sized-hydraulic-press-build.1477792/page-2#post-17009997

Short version is the press I'm building has a 2 stage 16gpm pump, a 4.5" cylinder and a 2hp 3450 RPM motor. It should make 24ish tons and move 2 inches per second at low pressure and 3/4" per second at high pressure.

Define how fast you want it to move and what tonnage you want to develop and work back from that. 4-5" cylinders will develop tonnage you want in 2500-3000 psi ranges. Pump sized based on how fast you want the cylinder to fill with the max pressure you need to make tonnage. Motor speed to drive pump at that fill rate with enough HP to do it.

I've got all my components and all the parts cut to build it I just haven't had time to weld it together yet.
 
I'm not doubting your calculations as I'm new to the hydraulic game. But I had uncovered in my research that
HP=(PSI/1500)xGPM
Or close to it. According to that math your 2hp motor will create 3000 psi at 1 gpm. 3000psi in a 4.5" cylinder is 23.86 tons. And at high pressure of 1gpm that's let's see. 1gal will move your ram 14.5" that takes 60 sec so 60/14.5=4.14sec/inch or just about 1/4" per sec. But I could be way off in my math.

According to the same math a 4" ram at 2500psi would be 15 tons and 1" per sec and require a 5hp motor. A true 1" per sec is rather quick when you think about it.
 
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That's what the 2 stage pump is for. How much ram movement is actually using full tonnage? Very little. It drops from 16gpm to 3gpm when pressure builds.

You may be right and it's still anemic with a 2hp motor. I've seen that calculation, but it assumes constant load.

So worst case I have to replace this $100 motor with a larger one. But it was worth taking a chance for me.
 
Is there a delay in switching from low to high pressure on these 2 stage pumps?
 
Not on my log splitter. I hardly notice.

I used to have a single stage 11gpm on my splitter and as the wedge contacted the motor would grunt and the ram slow down. When it went out I put this same pump on it. Now it contacts and the engine doesn't really change it's tone although the ram slows down, until you get buried into a knot and then the governor kicks.

I'm not trying to convince you of anything other than that a motor is easy to upgrade and reuse somewhere else. If you decide you got the wrong pump or cylinder what are you going to do with them?

I should pull the cover off the iron worker at work and see what it's running for guts.
 
And hopefully I'll be built before you start ordering stuff and have something to demonstrate.
 
If you want a press to be the be-all, end-all forging tool, you will need more than 15-20 tons. Preferable a LOT more. The only ones that i have seen whee you could probably say "i don't need a hammer' are the big ones like the Whitmus and Kyle Royer's machine. There are some cats out in the Northwest who have what to me might be the ultimate non-hammer forging machine setup and that is the Whitmus press and the rolling mill with the twisting jigs and squaring wheels running off of a shared hydraulic power unit. I haven't seen the prices for a few years, but back then, I think that combo was like $13K.
 
Speed kills and if you want a killer press you need speed. The only problem is building big fast presses cost big money..Even to build the very fast 16 tonners that larry Langdon builds costs him $5k+ in parts alone. I think like $4K alone for the power pack. 10hp motors and high speed pumps. Though they are lower tonnage they are so fast that they will out forge per heat presses twice their size.
 
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I think your 5HP electric motor will work fine. Use a 4-4.5" cylinder and a 22/11 GPM two-stage pump and you will get speed and plenty of tonnage.
 
jdm61 said:
If you want a press to be the be-all, end-all forging tool, you will need more than 15-20 tons. Preferable a LOT more. The only ones that i have seen whee you could probably say "i don't need a hammer' are the big ones like the Whitmus and Kyle Royer's machine. There are some cats out in the Northwest who have what to me might be the ultimate non-hammer forging machine setup and that is the Whitmus press and the rolling mill with the twisting jigs and squaring wheels running off of a shared hydraulic power unit. I haven't seen the prices for a few years, but back then, I think that combo was like $13K.
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This is along the lines of what I'm planning on putting together next spring, only I'll probably overdo it even more. Having watched videos of Ed Caffrey running his 80 ton press and seeing the gaps he can close in welding, I knew I wanted at least that.
My plan is starting with putting together a 100 ton press ran off a 10hp electric power pack. I'll be planning on adding a hydraulic rolling mill (which I've got a good design in mind for) and a second 10hp power pack (ran in parallel giving 20hp to cut the cycle time in half) as building time and money permits.

It won't be at all cheap, but should be about the ultimate setup. I'm usually of the mindset of start with something stupidily overkill, and never be wishing for more.

Either way it'll be an interesting build, and I'll post a build thread when I do it
 
The presses that I mentioned are at least 40 IIRC. I recall that someone, either Bowie or Tommy McNabb. used to offer a dual cylinder H frame press that was also like 40 tons.
Geoff Flato said:
This is along the lines of what I'm planning on putting together next spring, only I'll probably overdo it even more. Having watched videos of Ed Caffrey running his 80 ton press and seeing the gaps he can close in welding, I knew I wanted at least that.
My plan is starting with putting together a 100 ton press ran off a 10hp electric power pack. I'll be planning on adding a hydraulic rolling mill (which I've got a good design in mind for) and a second 10hp power pack (ran in parallel giving 20hp to cut the cycle time in half) as building time and money permits.

It won't be at all cheap, but should be about the ultimate setup. I'm usually of the mindset of start with something stupidily overkill, and never be wishing for more.

Either way it'll be an interesting build, and I'll post a build thread when I do it
Click to expand...
 
I've seen plenty of 40 ton presses, and they are definitely effecient. But after watching cafferys 80 ton close 1/4" gaps in Damascus billets and still make perfect welds, I knew I wanted something in that class.

I'm not at all new to machining and heavy fabrication, so it's definitely something I'd like to do myself. Drops of heavy I beams are cheap enough, just building the frame would be a substantial saving. Main cost would be the twin power packs, and all the various fittings and such. It'd be a huge time saver once it's done though.

Rolling mill should be a good step up as well, working on designing something that'll do 1/4" reduction per pass at a decent speed
 
Geoff Flato said:
I've seen plenty of 40 ton presses, and they are definitely effecient. But after watching cafferys 80 ton close 1/4" gaps in Damascus billets and still make perfect welds, I knew I wanted something in that class.

I'm not at all new to machining and heavy fabrication, so it's definitely something I'd like to do myself. Drops of heavy I beams are cheap enough, just building the frame would be a substantial saving. Main cost would be the twin power packs, and all the various fittings and such. It'd be a huge time saver once it's done though.

Rolling mill should be a good step up as well, working on designing something that'll do 1/4" reduction per pass at a decent speed
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1/4inch per pass seems like a LOT for a "home shop" rolling mill application. Those bigger presses the I was talking about were "four poster" designs with the exception of the McNabb (?). Is that what you plant go with?
 
I definitely agree it sounds like a lot, and is vastly overkill. But so is a 12x56 milling machine, and I've got one of those lined up as well.

I've spent enough time wishing I had something just a bit better, that I generally won't build or buy anything unless there isn't really an avalible upgrade from it. Same reason I bought a sewing machine that'll do 1 1/8" for doing 1/2" thick sheaths.


A lot of it is unnecessary but it makes the work so much more enjoyable, so if you can afford to why not?

As for press design, it'll be a two post, but the posts will be heavy I beams boxed in with 3/8 plate. I'd be comfortable running at least 200 tons through what I have in mind.

I guess I haven't done any big builds in the time I've been here, so I haven't really shared my machining and fabrication work at all.
Last one was a post vise stand. Base was 4" plate, column was 1/2" wall 6x8 box. Multipass weld that finished with a 1.5" wide cap pass holding it together.

If anything I enjoy the occasional heavy fabrication project even more than knifemaking, and usually use these sort of projects as an excuse to do it.
 
Why dual power packs? Our brake presses go up to 485 ton and they're all one motor, one pump, otherwise you end up with balancing issues.
 
The alternative would be a single 20-25hp power pack. I was hoping to keep it straight single phase, but it's definitely an option.
I always start the planning phase well in advance to get everything figured out before buying parts and building it starts. A friend of mine is an engineer who deals mostly with hydraulics, so I'll be running the design of all of that past him before ordering anything. I just haven't quite gotten there yet, still finalizing the frame and mechanical aspects
 
Stacy E. Apelt - Bladesmith said:
I think your 5HP electric motor will work fine. Use a 4-4.5" cylinder and a 22/11 GPM two-stage pump and you will get speed and plenty of tonnage.
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I can only seam to find 22/7GPM two stage pumps, or do you mean 22gpm ran at 1725=11gpm?
 
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