Could we see some pictures of that lawn mower? Been wanting to build a portable power source for years so I didn't tie up my tractor
Yes. I have posted before and they are here in my computer. I have to go to town but when I return I'll dig them out and post.
What happened was years ago I started splitting wood with my 2000 Ford tractor (30ish HP). Hyd pump was like 7 gpm and 2000 psi popoff, and by the time you put on a cylinder with any size to it and dealt with the 12' ス" hoses, it took all day and then some to do the wood pile.
I had an old Scotts 15 hp riding mower I wasn't using for anything. I stripped it down and installed a 2 stage pump system with parts purchased from Northern Tool and hooked it to my 4 x 24" cylinder with 6' ス" hoses. The pump I selected was their 16 gpm 2 stage pump requiring about 7 hp so my 15 hp Kohler single cylinder was more than enough. I'm running around 7-8 seconds on the unloaded cycle time, 7 in and 8 out with the cylinder stated. Smaller area cylinder would cycle faster but force is area x pressure applied to the area and obviously area is a governing element of time....flow rate x volume to fill.
On the 2 stage pump, if you are new to 2 stage pumps (as I was) the cylinder runs at high speed with a low pressure as long as there is no resistance. As soon as the cylinder pushes the log against the wedge blade, the movement stops for a split second and the pressure shoots up.
Once pressure builds and passes the low-high pressure setting, the speed slows to a creep but the pump pressure increases to the rated value and forces your wood onto the blade with the force of "area of the piston x psi of the pump". As soon as the log splits and the resistance is lowered where the pressure drops below the high pressure kick in, the speed picks back up again and your log is ejected.
So for a 4" piston and a 2000 psi pump, your force is [(4/2) squared x 3.14] x 2000 = 25k lbs of force. A 5" cylinder would be 40k lbs of force with the speed slowed by the ratio of the areas of the cylinder differences. For me, with the right cutter (pictures included) 4" gives a good combination of speed and pressure.
The adaption was a lot of fun and worked flawlessly. Since the picture was taken, I have replaced the high pressure circuit "water pipe" fittings with suitable high pressure fittings from TSC. Had no problems with the former, but since I sit right next to the mower to get to the control lever mounted on the frame, I didn't want a hose splitting and spewing hot fluid on me.