hydraulic cylinder for a woodsplitter?

[kljahnz]

I came across a large hydraulic cylinder a couple years ago, $75. most recently came across a NEW 20hp liquid cooled kawasaki motor $450. (business auction) Absolute steal. I admit hydraulics are pretty confusing for me, especially crunching the numbers. Anybody want to throw some expected cycle times and other helpful info my way. I figured a 28gpm pump from northern tool and the 20hp motor would be pretty strong, but may not be enough to power this cylinder.
the only identification on the cylinder reads. RCA-60021-03031-307081
the bore seems to measure 6.5 inch bore X 4.5 inch rod
the length is about 40 inches long, doesn't include the rod end.
bottom port measured inside the threads 1 5/8 in. might be a 1 3/4 in. npt ?
top port measured 1 3/8 in. (inside threads). might be a 1 1/2 in. npt ?
I would be using a cylinder stop to limit the stroke to about 26 inches, because I cut wood to 24 inches. I'll get a couple pics up of the cylinder, because the 40" measurement includes the bottom (pin hole) attachment. Just a guess, but I think it is closer to a 36 inch stroke.

 

[kljahnz]

 

[mga]

20hp??? I run a 6" cylinder on 12.5 hp and never had a problem. my cycle time is about 12 to 14 seconds complete.

 

[GM_Grimmy]

6.5" bore, 4.5" rod, 36" stroke with a 28 GPM pump, you are looking at 16.84 second cycle time, out and back. 11.08 seconds on the extend, 5.77 seconds on the return.

 

[SWI Don]

A 20 hp will play with a 28 gpm two stage pump. Heck my 18 hp will play with one and I turned the transition pressure up to 1000 psi. GPM and PSI determine HP needs. Cylinder size and PSI determine tonnage. Cylinder size and GPM determine cycle time.

You can run a very large cylinder with a very small engine / pump but it will be very slow but have lots of force.
You can run a very small cylinder with a very large engine / pump and it will be very fast but not have much force.
Above statements assume pressure is the same.

 

[kljahnz]

A 20 hp will play with a 28 gpm two stage pump. Heck my 18 hp will play with one and I turned the transition pressure up to 1000 psi. GPM and PSI determine HP needs. Cylinder size and PSI determine tonnage. Cylinder size and GPM determine cycle time.

You can run a very large cylinder with a very small engine / pump but it will be very slow but have lots of force.
You can run a very small cylinder with a very large engine / pump and it will be very fast but not have much force.
Above statements assume pressure is the same.

Thanks for the info.
What brand pump did you use on your splitter?And what is the maximum pressure rating? I can see the benefit in being able to raise the shift point (psi) before the second stage kicks in. If that is what you meant by raising the transition pressure to 1000psi.
In my first post, the bore measurement is the outside of the cylinder. The stroke measurement was also just a ballpark measurement. Which means I would need to measure the I.D. of the cylinder and a more accurate stroke measurement in order to get actual cycle time. But these estimates are plenty close enough to believe this combination has good possibilities.
The measurement between the ports on center is 36.5 in. I think I heard to subtract about 2in. to get a close guesstament. If that is true I could be closer to a 34in. stroke.

 

[SWI Don]

Thanks for the info.
What brand pump did you use on your splitter?And what is the maximum pressure rating? I can see the benefit in being able to raise the shift point (psi) before the second stage kicks in. If that is what you meant by raising the transition pressure to 1000psi.
In my first post, the bore measurement is the outside of the cylinder. The stroke measurement was also just a ballpark measurement. Which means I would need to measure the I.D. of the cylinder and a more accurate stroke measurement in order to get actual cycle time. But these estimates are plenty close enough to believe this combination has good possibilities.
The measurement between the ports on center is 36.5 in. I think I heard to subtract about 2in. to get a close guesstament. If that is true I could be closer to a 34in. stroke.

I have a Barnes pump bought from Surplus Center. 3000 psi. I have a 5" x 24" stroke prince cylinder I bought from Northern Tool. You should be able to split some long stuff with that cylinder. If you don't need that much stroke you may want to get some cylinder stops at your closest farm store to limit your stroke to your wood size. It will quicken your cycle time as the cylinder will come back less distance before tripping the end of stroke detent.

My build thread on another site. http://www.*****************/forums/showthread.php?t=8775

Have fun on your build.

Don

 

[ChoppyChoppy]

Or pull the cylinder apart and cut the rod down for a 26" stroke.

 

[WoodTick007]

Or pull the cylinder apart and cut the rod down for a 26" stroke.

Would you cut from the front of the rod and weld a new end on?

 

[ChoppyChoppy]

Would you cut from the front of the rod and weld a new end on?

Yeah, or the threaded end and rethread, all depending.

 

[kljahnz]

Well, I bit the bullet. I ran across what I thought was a good deal on a north star splitter on cl. Price seemed right compared to my progress on my home build splitter.

 

[cantoo]

That was likely your most cost effective move. Looks like a good splitter. Cut it up and modify to what you want.

 

[kljahnz]

The person I bought this from upgraded to a Tempest splitter. He did a demo for me to see the box wedge in action. I liked it even with a little more splitter scrap being produced.
Just putting the home built on pause.

 

[zogger]

Well, I bit the bullet. I ran across what I thought was a good deal on a north star splitter on cl. Price seemed right compared to my progress on my home build splitter.

Ya, that looks nice! Just change your home built into a full fledged processor now, at your leisure.

hey, we need truth in advertising with these splitters! 37 ton, ya right hook it up to tow and your wheels smoke and the hitch breaks off! That would be real 37 tons!

err..wait...