Ben Potter

Thanks for all the good input. I think that the pure hydraulic hammer is a nonstarter for a small shop. Just for giggles and grins what would happen if you took a double acting cylinder and attached your pump to the ram side and a precharged accumulator to the other port. Sort of like a breaker on an excavator. The hydraulic pump lifts the ram/hammer and when the valve is opened to tank the pressure in the accumulator acts as a spring and slams the hammer down?

First I have no experience with neither hydraulics nor pneumatics so this is all based on internet research. I have been crunching numbers for a new hydraulic press primarily looking at speeding up my air over hydraulic 20ton (a lost cause I think) and had the thought: Could you make a combination hydraulic press/hammer? Using a 2hp 120v two stage pump producing 1.37gpm @ 2500 psi and 5.27gpm @650. It would have 2 cylinders. A 4" one that would generate ~16 tons @2500psi and 1.6in/sec @650psi and .4in/sec @2500 psi for the press (think Coal Iron Works 16ton press) and a 1" one generating ~1 ton @2500psi and 6in/sec and 1/4 ton (500lbs) @650psi and 26in/sec. Adding a geared flow devider / combiner to the small cylinder should ad 90% to the speed producing ~ 49in/sec @250 lbs. For a 10in stroke that equals roughly 2.6 bps(less reversing time) straight or 4.9bps with the flow combiner. For comparison the early De Lisle Power hammer De Lisle Power Hammer on Youtube uses a 2 1/2" bore 10" stroke pneumatic cylinder running ~100psi producing 490lbs force at about 2bps. (the cnc version in the video is twice or more as fast) I know the pneumatic cylinder will hit faster and harder but it seems that it might be possible to get a passable hammer with the small hydraulic cylinder. Thoughts?