hydraulic forging press?

granpaw wrote in news:AdOdnZ7WVJwF59zYnZ2dnUVZ snipped-for-privacy@centurytel.net:

Duh.. Googled and found a few sites such as Dan Fogg's, but otherwise not much in the way of 'free' documentation can be found.

No matter how you slice it, it's gonna be expensive. To get a fast action you'll need a lot of flow from the pump, as well as high pressure, or a really short stroke length which will limit the flexibility of the rig. Big high pressure pumps aren't cheap; you get what you pay for. If you go the low presure route, you'll need a large actuator piston to develop the force so you can concentrate it in a small working area. Auto power steering pumps put up around 500 psi, but you can run several in parallel to up the flow rate, and they're fairly cheap and easy to get. You might consider an accumulator based system, where the pump charges an accumulator which then feeds the power piston. This will give you a high flow rate but a slow cycle rate, so you'll get a fast stroke but slow recharge between strokes. Needless to say, having lots of high pressure oil stored in tanks and plumbing can be dangerous, so build with lots of overhead. SAFETY. If I was going the build one, I'd use at least a 100% pressure overhead in the high pressure side ie 1000 lb limit for a 500 lb system. Good luck...

Charly

Charly the Bastard wrote in news: snipped-for-privacy@worldnet.att.net:

Thanks for the info Charly. I ahve about twenty vehicles out here in various stages of dis-repair so I will be looking into the power steering pump method. I need to learn some hydraulics anyway so this will be a good starting point.

granpaw

I built a 30 ton forging press from Jim Batson's plans, which I highly recommend. You can get them from Norm Larson ( snipped-for-privacy@impulse.net) among other places (Norm is a pretty fine guy). There are two sets, the first has a huge wealth of general info on how to put together a hydraulic system like this and has plans for a floor standing I beam based press. The second booklet has details on how to build a tabletop model (same kind of tonnage, just sort of folded).

They are fine tools, you can do all kinds of stuff with thick metal. You can't do a lot of forging on small stock. I've used mine to draw down tong reins (with fullering dies). You can also take a piece of 3" round,

8" long and put it on end (hot) and smash it into a grapefruit sized piece. I like taking large hex stock and squishing it into barrel shapes.

The way you make them move fast enough and have enough pressure without a huge motor is to use a log splitter pump. These pumps are two speed--at low pressure they pump fast, when the pressure goes above a threshold, they slow down (about 4:1 I think). This way they don't chew up a lot of horsepower. My 30 ton press moves at one inch per second (no load) and runs on a 2HP motor. Their shafts can't take side loading--you have to drive them with a coupler, not a pulley and belt.

If you're a good scrounge (very likely), the pump will be the most expensive item. Cylinders can be bought new/surplus/used (see below); I got mine at a country junkyard that had a lot of tractor parts. I bought two 6" cylinders out of a trash truck for $75 (total).

Two mistakes in one that I made: the logsplitter pumps are rated to operate at 3600 rpm. This is probably tolerable if they are on a gas engine. On an electric motor, they absolutely scream. Don't run them this fast, run them at 1800. Part two was that I originally set my press up for 2" per second movement. This is ok if you're forging, but the first time you bend something it gets really scary. 1" per second is plenty fast.

I built the I beam type. Mine is a 7' long beam with an 18" web (this is a C style press instead of an H style). On the face of the beam is welded a 3/4" x 8" wide piece of dozer blade for reinforcement. It is large and heavy. Unless you absolutely must have a C style press, I really recommend the H type. These work well in a 'table top' model. I'd do it that way if I was doing it over.

A press *excels* at making pattern welded steel. Tack weld a billet together on a handle (say 2" square and 6-8" long), flux it, get it hot, and make it maybe 1/8 " thinner in the press. I do it once more just to make sure (reheat and flux), then I go to drawing it out, flat or on edge doesn't matter. No quicker way to make a bunch of pattern weld.

When I'm making tooling for the press, I try to figure out how to get the most done in one stroke. Many times that's all you get before you have to put the piece back in the fire (the dies suck the heat right out).

Steve

granpaw wrote:

Pumps are not very expensive, they can be bought on industrial liquidations for not too much and will have a lot of horsepower and will likely be of exceptional quality. (of course you need to have 3 phase, which I assume most of you do).

You can buy hydraulic cylinders from a variety of sources, for example I am selling cylinders with 8" bore, and about 24" stroke right now, I have two. (shameless plug) They are from a military 50,000 lbs rough terrain forklift.

Making a proper frame for a high power press is certainly a challenge as far as making it safe and sound is concerned.

I would just look for a industrial A or H frame press at liquidations, again, they are not expensive and it is easier to buy something made than spend forever scrouging I beams and welding stuff and grinding off bad welds.

Ergo

600 ton press in Chicago. (A little hard to believe this number, be careful)

I am not affiliated with the seller, though I bought quite a few things on their auctions.

i

Same here. Could be a typo? That's not much cylinder _or_ frame for 600 tons, going by a guess at the size of the compressor next to it.

I could ask if my old employer is ready to sell the old press: 20' above the ground, 20' in the ground, 40" ram, would reduce a 40" x 72" round billet to 10" thick in about, oh, 10 seconds. Of course the billet was at 2300 degrees at the time and the pressure was right at 5000 psi but it was still one heck of a hydraulic forging press.

Oh, yeah, after the Big Squish, then they went and punched a hole in the donut with an auxiliary ram mounted on the side of the main one. Somehow I never got tired of watching that thing really: Squash, make flat!

Not _the_ biggest press around, but adequate for the home workshop.

Looks like a 50 ton press to me.

Sounds a little undersized. ;)

i

Hi gang, Time for a gloat here. I just traded my monster Johnson gas furnace for a pristine, 25ton,4 post shearing press! 7hp, 18x24 platen. it's not the best configuration for forging but I'll make due or tear it down and build it back as a c-frame design. I am more interested in working sheet material anyway.

John Husvar wrote:

Sounds like a fun toy. If you make pattern welded steel with it, *don't* bend over to watch when you squish the billet. Flux sometimes comes out in a blob, orange hot.

Steve

GSG wrote:

Does the flux ooze, or go supersonic? Sounds like too much flux though. I have caught my share of it on power hammers. Owwww under my gloove! left a 1/16" deep crater on my wrist.

GG

Steve Smith wrote:

It reminded me a lot of someone spitting tobacco, much slower than flux coming from hammering. Almost certainly too much flux on my part. I was using plain borax. What I picture is a pocket in the middle of a layer finally getting enough pressure on it to find a outlet.

Steve

GSG wrote:

Not recommended for human tissue!! Ya think? I would like to do some pattern welding on the press but it is set up more for die forming sheet gauge metal. The top and bottom platens are about 24x18" with 4 corner posts. So it is awkward to set up and change tooling. Better for forging would be an open frame setup. A buddy used the hydraulics(25 ton 5hp) from a wrecked cardboard compacting machine and built a double C-frame from 16" I-beam. 36" throat and about 12"stroke. He shapes sheet and plate steel on simple homemade dies. Works like gangbusters. It's a good configuration for forging as well. Anyway, I'm waiting for enough money to "rig" my press over to my shop. Got to scoot.

Glen.

Steve Smith wrote: