Have a look at Don Fogg's page and don't miss the 5 or 6 other pages with links at the bottom of the page.There is a booklet he sells there too which runs through specs and designs by an actual engineer.-the Baston bookA pre made shop press is usually unsuitable because it achieves its high power with a large cylinder at a very slow stroke speedA forging press is usually recommended to have at least 1 or 2 inches per second stroke speed so you can move metal while it is still hot.If you start doing calculations you will see that it is easy to get a high tonnage, but at a slow stroke speed because of the volume of fluid required.This takes a large pump and motor.You may have to reach some sort of comprise on a slightly smaller 5" cylinder instead of 6".It starts costing real $ to up your pump volume, motor HP and wiring size above 5 hpIs 50 tons twice as good as 25 ? probably not as good as a fast 25The larger size will allow you to run larger dies and keep the same PSI at the die level...but there must be a practical limit..in the numbers Billy gave he is running 2200 psi is 21.5 tonsBuy the book , look at what others have done and do the calculations with what you can buy locally.I would tend to stay with 5 or 6 inch cylinder, go larger on the pump volume and keep the pressure down to keep the stroke speed up so you can get more squeezes per heat in.When the steel is hot, you wont' need huge pressures to move the steel and are better served by gradual reductions to preserve your patterns.the difference between the pump volume at 5" and at 6" is significant.10 hp dual pump hydraulic station pushing16 gallons a minute at 1500 psi.5" double acting hydraulic cylinder with an 8" throw.Works out to 14.7 TonsNORTHERN 1053-C161 BARNES 2 STAGE PUMP -11GPM2010-C161 PRINCE STANDARD 4-WAY CONTROL VALVE4051-C161 7 GALLONS HYDRAULIC OIL TANK MUST CLEAN THE INSIDE WELL4022-C161 RETURN LINE FILTER4010-C161 SUCTION STRAINER THIS GOES INTO THE TANKFITTINGS AND HOSES YOU WILL NEED 3 HI- PRESSURE HOSES AND LOW PRESSURE HOSE FOR THE RETURN.53606-C161 GLYCERIN FILLED GAUGE 0-3000PSISURPLUS CENTER 10-1485 ELECTRIC MOTOR I USE A 3 HP AT 3250 RPMS09 4954 HYDRAULIC CYLINDER I USE A 4 1/2" BORE X 8" STROKE WITH THE PUMP AND MOTOR SHOULD GENERATE 24 TONS__________________with automated stroke timingMotor – 7.5 HPPump – Single stage 5.2 GPM (Single stage is necessary to get repeatable timing for an automated stroke)Cylinder – 5” X 8” Stroke**************220V motors are practical in these sizes
I have read enough accident reports on presses to last for a long long time. Two years ago a lady I knew sawed off a hand. Harborview (Seattle) was able to put it back on and were pretty sure she would regain 80%.
20 years in health and safety field.
The speed of advance and electrical controls are main issues in my mind. I could easily agree with two hand control or a curtain and not blink an eye at the cost. I think you are correct.
Quick war story In about 1991 at Boeing where I was Health and Safety another safety guy brought me a diagram for controls on a sheet metal shear. I could see the motor and contactor normal 3 phase and teh light curtain. BUT all the control wires went to this box on the print that said AB xxxx.
So we went to the equipment engineer and I asked him what this AB xxxx gizmo was and why all the controls are going to it. He says its a PLC kinda like a computer and does all the controls. I worked with the guy and knew I could trust him so I said I know nothing about it - can we really trust it. He said yes BUT we will test to ensure - think you should be there anyway. It worked trouble free for at least five years that I know of.
When I learned a little on PLC I started wondering if I had made the right decision.
Dan Bentler
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