SaratogaSmithy

Thanks poleframer for the helpful information. I did talk to the tractor dealer’s service person about my Kubota L4610 tractor. He did confirm that using the hydraulics to run a log splitter can be a problem if the flow is cut off without a pressure relief. The pump will break up. They do sell a retrofitable option to install a remote valve with detent mounted on the fender, an additional set of QD’s, and overpressure protection for a bit less than $1000.00. Ouch! I also got some better performance numbers for my nominal 40 HP hydrostatic drive tractor. The hydraulic system pressure is 2400 psi new and I should use 2300 psi. The free flow is 7.7 GPM and I should derate that to 6.7 GPM at max pressure. Assuming my cylinder bore is 6.5 inches, the max pressure would be 75,900 pounds and piston travel at max pressure would be 0.75 inches per second max velocity. Long, skinny hydraulic lines with tight turns would slow it down quite a bit. So I am thinking that if I really need to spend $1K to protect the tractor, I could buy a used hydraulic electrically driven power supply for maybe the same money. Back to the drawing board.

Thanks for the helpful suggestions. I'll double check with the tractor dealer's service guy about twcoffey's concern about limiting pump life, as well as firefarm's comment about valveing and if continuous flow is available. I've sent a PM to poleframer asking about his experiences. I don't know the actual piston diameter, but the outside diameter of the cylinder is a bit over 7 inches. Assuming the piston is 6.5 inches in diameter, and limiting max pressure to 2500 psi (tractor max is 2850 psi), that should give me a 75,000 pound push (area x pressure). I would then size the fame for 100,000 pound design load and a 1.5 safety factor. Using A36 steel yield of 30,000psi would require less than 5 square inches of frame work to resist the tensile load. I expect the bending load for the top and bottom members of an H-frame press would the critical design factor. I am thinking that 12.0 inches inside to inside dimension of the frame would be the minimum width. A C-frame press would be a bit more complex, but might be worth the added working room. Any and all comments on the above thinking are most welcome…

I am planning to build a hydraulic press possibly using my tractors live hydraulics for the power supply. According to Kubota, my nominal 40 HP tractor can supply 20 HP hydraulic power at 2850 PSI. The tractor has a set of quick disconnect fittings where the press can be connected. However all the external lines on the tractor are ½ inch diameter, which seems a bit small for much flow and subsequent slow piston movement? The cylinder I am planning to use is 7 inches outside diameter and has a stroke of about 12 inches. I am wondering if others have tried to use the tractors “live hydraulics” to run a press. To keep the supply and return lines short, I also wonder the wisdom of welding attach points on the press frame to interface with the tractors 3-point hitch points and back the tractor with press up to the hot shop door, next to the forge. Protection of the hydraulic lines (and the rest of the tractor’s rear end) with metal shields is also envisioned. Comments and suggestion are welcome and appreciated.

I count myself as one of the lucky ones who knew Tom. He delivered one of his 50kg Saymak hammers to my shop after the ABANA conference in Seattle, and then I went to his school a couple of months later to learn how to use it. The class was taught by Bob Patrick, and Tom always quick to help out with demos or advice. He was the epitome of the Energizer Bunny both at the conference and at his school, but he would slow down to answer questions, offer advice, and kept an amateur like me out of trouble. When I learned from Bob Patrick that he was ill, I called to see how he was doing. He was very positive and upbeat. Tom wanted to know how I was doing more than talk about his situation. The blacksmithing community has lost a great friend. Tomorrow my anvil will toll for Tom using one the hammers he made. That hammer will be a good reminder of Tom, his skills, and boundless enthusiasm.

I have a decent hand crank blower here in Washington state, but it is not new. Works well, and it is heavy cast iron - freight could be expensive. Let me know if you want more info or photos. -Bob