Cylinder size

[rogerfries]

Looking to re-work my splitter. I currently have a 4" bore cylinder 30" stroke running at 2,300 PSI and it stalls often. considering a 5" or a 6". 5" is much less expensive and price does matter, but even taking price out of the equation, the 6" will move much slower than the 5". With a 28 gpm pump the 5" should have a 10 second cycle time and the 6" will have a 14 second cycle time.

The question is will the 5" have enough power?
Is the extra power of the 6" worth the extra 4 second cycle time?

4 seconds does not sound like much, but hundreds of cycles per day it adds up. I estimate I would need a 38 GPM pump to match the 10 second cycle time and I'm sure a pump of that size will be expensive if I can even find one. I'll have plenty of horsepower available, so no issue there.

Opinions: 5" or 6", speed or power

 

[triptester]

Your 4" bore is producing 28,903 lb. of force.

A 5" bore will give you 45,160 lb. of force almost a 50% increase.

A 6" bore will give you 65,031 lb. of force more than double what you have now.

I have not seen any 4"cylinders damage beams but I have seen a couple 5" cylinders twist and distort splitters. A 6" cylinder may require starting from scratch.

With a 5" cylinder stalling seldom accures and with greater force at any given PSI the wedge will travel further before the 2-stage pump down shifts helping to equalize cycle times during actual use.

 

[CaseyForrest]

Why not turn up your relief valve? Dont go over the rated psi of your cylinder, fittings or hoses, but 2300 is a bit low.

 

[rogerfries]

I'm planning on building a new frame. I had so much fun building my log lift, I'm building a whole new splitter from the ground up. To be the "mother of all splitters". I Think I'm gonna use a 5" cylinder, but want to build it for a 6" so it could be upgraded later if necessary. Any Idea what size beam would be required to handle a 6" 3,000 psi cylinder? My plan is to use rectangular tube 4" x 8" @ 1/2" thick. With a piece if 8" x 1/2" flat stock in top to guide the ram. I want to be able to raise the 4 way head higher than my current one so this brings in the leverage thing. Also want to build a 6 way head. I want to start with a beam that will be unbreakable for a 6" cylinder and don't know how to figure that out.

 

[stumpguy]

what are you splitting to make your splitter stall so often? do you have a two stage pump? i have a little 20 ton rig i built 15 years ago, and i can count on one hand the number of times it has been stalled.

 

[rogerfries]

I tend to get allot of ash, and the big ones and the knotty ones will stall it. By stall I just mean the ram stalls, not the engine. It's not uncommon for me to be splitting 36" diameter logs. I put a gage on it to see what the pressure was. I could dial it up a bit, but I have no idea what the piston is rated for, so I have to assume 2,500? I'm at 2,300 and I don't think a extra 200 psi will have a large effect and I don't want it blowing up in my face. I also use a 4 way head which probably makes things harder. A friend of mine has a brand new American MSR splitter his also has a 4" bore piston also and his stalls on about the same pieces as mine does. I haven't found anything I can't split, but it's not uncommon for me to have to re position and try again in a different spot usually closer to one side rather than dead center. If I go through the trouble of building a new one I don't want it to stall, ever!

 

[mga]

i'm using a 6 x 24 cylinder, mounted to an 8" H beam. the H beam is 3/8" on the flats and the web is 1/2". it's been splitting some tough wood and so far no problems.

 

[tocold4u2]

my home made splitter hasen`t stalled , but if i think it`s gonna get into a bind , i`ll back it off and re position it .not sure what the largest chunk i`ve split, but there has been some big ones. i think that if you go with a larger cylinder , then you will have to go with a larger pump or you`ll have a slower cycle time .
good luck

 

[rogerfries]

MGA,

How is the cycle time on that 6"? What size pump do you use? Do you think It's worth going for the 6", or is 5" plenty?

 

[Buckeye]

I would try increasing the pressure to 2750 PSI before buying a new cylinder. I think that 3000 PSI is the generally accepted maximum for most components.

 

[CylinderService]

Roger,
I agree with you about pressure ratings for your cylinder and other components. If you don't know, I wouldn't assume anything over 2500 PSI. It doesn't mean it will explode if you go over that, but you would sure be trading away your safety margin. I often liken it to driving your car 100 MPH - it may do it, but you're going to have a lot more problems. (Unless you've got a lot different car than I have!)

Don

 

[mga]

MGA,

How is the cycle time on that 6"? What size pump do you use? Do you think It's worth going for the 6", or is 5" plenty?

cycle time is roughly 12-14 seconds. plenty fast for me when working alone. my previous splitter had a 5" cylinder and my brother in law bent the damn thing. with this 6" cylinder, it eats everything without so much a grunt.

my pump is a barnes 2 stage...22 gallon tops.