What to aim for in a forging press?

[Damastang]

Thought i would start a new thread, could not find anything in the search.

 

Whats everyone's opinions on optimum tonnage and ram speed for a forging press? Primarily for damascus billets, nothing seriously heavy. I am getting a little confused with the variety of presses out there. Some say 25 tonne is not enough some 35 tonne is what you need for damascus yet some say 16 tonne is enough. Some say 3+ inches per second of travel is idea while others say 1-2? Who has a press out there and whats its specs?

 

Kinda regards

[Ric Furrer]

What is "nothing seriously heavy"?

One limitation is how large a motor you wish to power. The motor dictates flow and pressure.

 

 

So:

How large a motor can you run (or how large do you wish to run)?

What is the sized billet you wish to forge most of the time?

What metals in that billet?

Will you use a lot of embossing dies?

Are you creative with tooling or do you wish to just place the billet there and push?

Are you prone to fits of anger and rage when you don't get your way immediately?

Will you fabricate this yourself and are you handy at that sort of thing?

 

 

 

I forged for years under a 36 ton press at 0.6" per second 3hp motor...sold it to a friend

Moved to a 45 ton and 0.7" second 5hp motor...sold it to a friend.

Now I have a 24 ton at 1.3" second 3hp motor as my main press.

 

In Summer I'll have five presses ranging from 150 ton (75hp motor) down to 10 ton for some specific operations......but I am a bit odd.

 

The key is creative tooling.

 

 

 

Ric

[basher]

Lots of speeds and tonnages work. I went and visited a lot of presses before building mine.

 I ended up with low tow tonnage and high speed 12  to 18 tonnes (I have it bypass at 12 tonne )and 2 inch per second  (lots of Hp though). and that works for me. I would seriously try and have a go on some existing presses before building one.

 All the best owen

[arftist]

Hard and fast.
Another area where mechanical rules and fluid drools in terms of performance/hp.

I would look for a motorised flypress for best bang/buck.

If you really want to build the thing, and damascus is your primary goal, look into a Mcdonald rolling mill. way less material cost than an hydraulic press and possibly more utilitarian for knife blanking.

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[Damastang]

Thanks guys, and Ric, not sure what the aim of this statement was "Are you prone to fits of anger and rage when you don't get your way immediately?" I have been researching for pretty much a year now, bought Batson's book at the very start and have been talking to heaps of people who work with hydraulics. Just trying to get a few people's opinions. And yes i will fabricate it myself and yes I am handy with that sort of thing. Welding and fabrication is my occupation.

 

Well our hydraulic guru at work said a while back the first thing you need to establish is what tonnage and what speed you need, then build off that hence why i asked those questions. I can buy a 3hp motor, 5hp motor or 7hp motor, it doesn't matter. One way is going to be cheaper of more expensive than the other. Are you happy with the speed of your 24 tonne press Ric? At this stage that's pretty much what I am going for.

 

I have considered a rolling mill but i do plan on doing some creative stuff as well as using it for punching holes and other general uses.

 

Thanks for the input guys, keep it coming. I am reading and learning.

[swedefiddle]

How much Tonnage = My shoes are shinyer than your shoes. My truck has more power than your truck. etc.

Tonnage = Pounds per square inch. If you are pushing a knife edge, a 10 ton press is pushing over 100 ton per square inch.

 

Figure out what you wish to do, make or purchase a press to do it. Learn about Basic Hydraulics.

I have used a hi/low pump for years. High volume/low pressure = high speed/low pressure / Low Volume/high pressure = low speed/high pressure.

A fast approach, a slow hard push. Friction makes heat, hard push retains heat. Maintaining heat, maintains the plastic state.

Have the press work fast when there is nothing in the bite, Have control when it is under pressure.

 

just my $.02

 

[Ric Furrer]

I said fits of anger because I see some who think they are building an "infinite pressure" machine and get frustrated when the tonnage is used up.

I have some large presses for sale..12" cylinders..and some folk call all excited about that. I ask how much electricity do you have and they say 120 volt 20 amp.......so in the end they can not power the motor required to move the cylinder fast enough to do any forging.

 

So if you can run a 7.5hp motor I'd say go with that..or 5hp at minimum.

If 5hp look into a 22gpm Hi/Lo pump running a 1800rpm (making 11gpm x85% eff so about 9.3gpm) rather than 3600 with a smaller GPM as the slower rpm larger pump runs quieter than the smaller faster rpm pump. you can run a 5" cylinder with that power pack and be quite happy with rather fast 24 tons at 2500PSI and about 1.8"/second at the pump at low pressure high flow and that will drop to about 1/4 flow (0.45" second) at full pressure.

You need about 8 ton per square inch to move hot carbon steel..so that would be good for 2" square no problem..........smaller dies for drawing means more work per push. when yo get to 1/4" thick blades you will get much less work done, but you will adapt to that in short order.

 

I do some work where 24 ton is too much force and others where 1,000 ton is too little.

 

 

ARFTIST...........I'd very much like to locate a 300 ton friction screw press.............know of any?

 

Ric

[Damastang]

Thanks Ric

 

What do you think about a 5 HP 2850 RPM motor running a 16 GPM Hi/Lo pump (12.7 GPM at 2850 RPM)? Going by my calculations this will make 24.5 tonnes at 2500 PSI with a 5" bore cylinder and a travel speed of about 2 1/2" per second unloaded. If you have a sec can you check those calculations?

 

Very similar to the system you listed, I can get the 2850 RPM motor at a good price, our options are pretty limited here in Australia. We also run on 50 HZ power instead of the 60 HZ you guys have over in the US so no matter what anything over 3000 RPM is out of the question unless 3 phase is used which is unavailable to me. Also what affect does torque have on all of this? the 2850 RPM motor should have more torque, 1800 RPM even more? My thoughts are that the motor will hold it's revs a little better under load?

 

Cheers

[SJS]

Its just important to know yourself, some people don't handle frustration, if you know that about yourself, build bigger, better, faster, more!!! if you are patient you can enjoy a slower press that you have to be creative with...  I am not a good match for a mechanical hammer, I much prefer an air hammer...  That's just me knowing myself, other people can do great work with a mechanical hammer, and their cheaper...  He wasn't impugning your character;-) 

[Damastang]

Well one would think after using a hand hammer to draw billets over the horn for hours on end in the hot tropical heat that I would have the patients to pull a lever and watch the press do it for me ;). By using the press I am looking to reduce the amount of coke used per billet and the amount of material lost to scale. Those 2 things were my biggest issues.

[arftist]

 

 

ARFTIST...........I'd very much like to locate a 300 ton friction screw press.............know of any?

 

Ric

Nope.

Know of lots of 20- 100 ton ones though. You know, the range the OP is asking about? 

 

 

 

 

[Badger1875]

Hi folks, I build my 4th hydraulik press and ended most likely satisfied. It goes up to 22 tons, the speed is about 3,3 sec for a 4 inch down and up stroke and it runs on a 7,5 kW 3-phase electric motor. The press gives me enough power for forging and drawing a 6 pound damascus billet. If I intend to do so, it will go through a good warm 2 inch steel rod in one stroke. There are a few vids on youtube, check

and watch part 1 to 7. If you have questions feel free to ask! Greets from the icecold Germany... Freddie

[Damastang]

Now that's fast Badger! haha, maybe a little too quick for me. One thing I have noticed watching presses with the 2 stage pumps is that some of them pause once they have made contact with the material before engaging the low gears. This sucks a lot of heat away yet some of them hardly look like they are slowing down at all. Not sure if it has to do with the pump or something else.

[the iron dwarf]

I use a single speed 30 ton press for cold work, even when near its capacity it is hard to see it slowing on contact, like when bending 1" ( 25mm ) square steel into a 180 degree loop with a 7/8" ( 22mm ) internal radius, takes less that 2 seconds from contact to the loop being ejected and it goes in cold but comes out hot. takes about 6 seconds to put 8" ( 200mm ) bar in place, bring down press, remove ejected loop from under tool and be ready for next one. press has 10" (250mm ) stroke but I set it to less for speed 3hp motor drives it

[Badger1875]

Now that's fast Badger! haha, maybe a little too quick for me. One thing I have noticed watching presses with the 2 stage pumps is that some of them pause once they have made contact with the material before engaging the low gears. This sucks a lot of heat away yet some of them hardly look like they are slowing down at all. Not sure if it has to do with the pump or something else.

 

Thanx, but speed is the most important thing! You already recognized it, a slow press sucks the heat out of the material and this is contra-productive in making damascus steel.

If you use a two-stage press, the first stage goes with about the double conveyance-mass than on the second stage, this is why the piston slows down. The ratio depends on the setup of the pump.

 

If you are calculating, think about: double speed needs double horsepower to reach the same pressure! When it comes to building up pressure, the pump itself changes to half or less of the conveyance mass to handle the upgoing pressure with the same horsepower. I have an excel sheet for calculating speed, pressure and conveyance mass, but I don´t know how to upload it, mail me your mail-address, I send it to you...

 

Freddie
 

[forgemaster]

Iron Dwarf that must be one real good press, 30 ton with a 3 horse power motor and can bend 8" bar into a loop in 6 seconds.  I have 80 tons and it can't do that.  I think even the 450 ton press may struggle if its not hot.

[arftist]

Iron Dwarf that must be one real good press, 30 ton with a 3 horse power motor and can bend 8" bar into a loop in 6 seconds.  I have 80 tons and it can't do that.  I think even the 450 ton press may struggle if its not hot.

You misread it Phil.

[the iron dwarf]

inch thick and 8 inch long, will post a pic after work

[forgemaster]

Misread it?   Ya think so?

[the iron dwarf]

 

here is a reject, one leg is longer than the other

 

[Andrew T]

Freddie, that is a fast press!

Can you tell us about the pump and the basics of how you built the press?

[basher]

That is avery impressive press Freddie.

 I bought the basics to get my press reciprocating like that with a solanoid valve block , but never got around to it. You have made me think it is worth persuing. what are you using as a depth stop for the top and bottom of the stroke.is it a microswitch?

[Damastang]

Well i am progressing along pretty well with this I think, but I have a few more questions.

In Batson's book he says to use 1/2" high pressure lines and 3/4" low pressure and suction for a 16 GPM or less system. It really makes my life a lot easier if 3/4" hoses can be used all round, would this work for the high pressure side of things? The ram has 1 1/16" ports on it so I have plenty of room to play with adapters. Not sure what effect a bigger high pressure line would have on the system.

 

Also I still can't decide whether to mount the ram up top and push down or mount it underneath and push up. I have no real height restrictions but don't wan't the thing tipping over. What are the pro's and con's of each? Seems a lot of knife makers have the ram pushing down, makes sense to me.

[Dahlia's Daddy]

Larger sized hoses may actually be better since you would have less restriction to the flow.  Any time a fitting is used, it is going to slow down the overall flow too.  Hydraulic lines aren't very stretchy, so the fitting will reduce the ID and then it gets bigger after the fitting again.  90 degree fittings with larger sweeps are a better option if possible as well.  I haven't built my press yet but have been doing A LOT of reading.

 

Pick up the Womack Industrial Fluid Power vol. 1 book if you can, their website is very helpful as well.  The book explains a lot of the how and why of how fluid power systems work.  Their books cover air, hydraulic, and vacuum systems, and are very well written and easy to understand (at least volume 1 is so far!).  I believe the later volumes cover things like solenoid controls too.  The books will also familiarize you with symbols used in circuit drawings, which may or may not be helpful to you.

 

I personally am going to go for the H-frame up-acting press in the middle section of Batson's book.  Takes up a lot less space, and on wheels it could be moved around if needed pretty easily.  I'm going to build the power pack off the machine on its own cart too to keep my options open further down the road.

[Damastang]

Thanks. Yeah the main problem I am facing is the control bank. They are either all 3/4" or all 1/2" ports, not a combination of both like the northern tool ones. If I bought a control bank with 3/4" ports would it be worth reducing the high pressure ports down to 1/2"? Why is 1/2" used? Does 3/4" take more fluid to fill and therefore more fluid to build up pressure which equals a slower ram speed? Or am I looking at it wrong?

 

Also can a detent control valve really be used for forging press? From what I have been reading the detent feature automatically retracts the ram it's full stroke as soon as the lever is moved into the "up" position? How does this work and is there a way bypass it and use it like a normal spring centered valve without detent?

 

Cheers

Ryan