New to me homebuilt log splitter help

[LD1]

If it takes 4 seconds to extend fully, you are only getting 11GPM to the cylinder while trying to force 30gpm out of the pump. BIG restriction. You really need a smaller ~15gpm pump, or even a 2-stage. IF you plan on keeping it tractor driven, you have the HP to NOT need a 2 stager. The 2 stage pumps are if you want to drive it with a much smaller motor. If a smaller gas drive motor is in the future, the go with a 2-stage for sure.

 

[Diamondpilot]

If it was me I would scrap the pump and plumb it to run off the tractors hydros via the remotes with 1/2" hoses. I would also put a 4"x24" cylinder on it to get some real power.

Chris

 

[J_J]

Working with what he has, I would recommend he use the 540 on the tractor PTO, to run the pump, putting out about 15 GPM's. There is probably nothing he can do about the lines on the cyl, and if he wants a 4 or 5 in cyl, the complete base will have to be rebuilt, including a thin sharp wedge.

It is just not a good match up, somebody just used what they had.

 

[LD1]

It is just not a good match up, somebody just used what they had.

+1

Perhaps if you could find a 5 or 6 in bore cyl.
You could run that pump at a lower rpm, and less GPM, and still have the pressure.

15 GPM feeding a 4 or 5 in cyl would work well.

It only takes 21 HP to run that pump at 15 GPM's, and 2000 psi

A 5" cylinder would give a ~20 ton splitter.

And slowing down to 15gpm would result in a ~15 second cycle time with a 5" cylinder. About 8 to extend and 7 to retract. That is pleanty fast enough and about what commercial units run. BUT your splitter will actually be faster. Because those 15 second ratings on commercial units are with the 2-stage pump on high. As soon as they hit the wood they slow WAY down. Yours would NOT. It would maintain the speed through out the split:thumbsup:

On a side note, I would NOT run it off the tractor hydraulics. IF the JD 710 you speak of is the one from the 1960's, it only has a 4.75GPM pump. THAT would be like a commercial unit on LOW SPEED. It would be painfully SLOOOWWW.

 

[kilohertz]

Wow! Well, I have definately landed at my new favourite forum. You guys are awesome! :thumbsup: Thank you so much for the thoughtful replies. :dance1:

Where to start? I'll just ramble a bit here and hope it makes sense. I would LOVE to put a 5" cylinder on it but as mentioned, would require complete rebuild. I nice winter shop project. I would also like to make it portable, towable behind the ATV, again, a new frame is in order. A lot of your great ideas, would require a new unit to be built, and right now, I just don't have the time to start from scratch. I like J-J 's idea of running it slower, which I have tried, but the pressure drops to about 1200PSI at much slower than half tractor throttle, which I think means the pump is bypassing internally. Yes, 50HP is about what she is putting out to get the PTO at 1100RPM. The engine speedometer is broken but I am pretty close about the RPM. Yes LD1, she is the old 60's Mannheim German built 710, with real poor hydraulics as it is, which is why I have pooopooed the aux hydraulics at the rear. The tractor is no where near stalling when loaded, but you can tell there is a load on the PTO.

Now, the hose sizes, yup, pretty small, especially the steel tube feeding the extension side of the cylinder. J-J, the control valve is a Gersen 2712 tractor valve, no kick off, just using one of the double spools on board. BTW, when I turned up the pump PRV, I was able to get 2000PSI at 1100 RPM. I know there are more turns available on the pump, so I will now try to crank it in a bit more to get more PSI at a lower RPM, thus reducing flow, and restriction, and HEAT. I ceratainly don't need 4 second times, and would be happier with everything running cooler, and safer. Yes, the resevoir is too small for 30GPM, maybe even 15. I would like to have about 15 gal reserve but again....time and materials.

I think, just to summarize for now, pick up that 4" cylinder for $75 (or a 5" if I can find one), change the knife (to the new dozer blade cutting edge I got yesterday), turn up the pump PRV to it's max of 2500PSI, and slow it down to 540 RPM, insert the return line filter, change the fluid and try it again.

Thank you again for the continued training in hydraulics. This is my first foray into hydraulics and I LOVE them. I am a decent mechanic, having rebuilt auto trannies, transfer cases, rear ends and engines, but I have never played with hydraulics. I have a Linde 295 stick welder and oxy/ace torches etc., a good collection of scrap steel, grinders (welders best friend) and 900 sq ft shop to play in, with (soon to be installed) wood stove.

Cheers for now.

Paul
:drink:

 

[kilohertz]

Update....

Tonight I cranked up the pump PRV to max, minus 1/2 a turn, and was able to get 2000 PSI at just off idle...about 800 tractor RPM. I split wood I was unable to before, and the hydraulics stayed much cooler, actually just warm. Before, they were almost too hot to touch which is about 50C. So I ran it for about 20 minutes and the hydraulics only got hot when I started stalling the RAM, but hey, it's a big improvement!!:thumbsup: I split some nasty maple and oak that wouldn't split before.

Thanks again...more updates as I find time.... and pics

Paul

Update....the cylinder is now leaking just a tiny bit under pressure, leaking right at the little clip thing at the end near the cylinder thread on end. It's leaking dark brown, yukky old fluid, not the clear stuff from the active system. Must be some old rusty stuff from sitting for years not used.