Logsplitter early stage planning questions

[chrispy6822]

Currently own a 35 ton commercial unit, but thinking of making my own just rather then improving on this one (log lift, table, etc).

My question is regarding cycle time. It seems like all the commercial units that I have studied all have a 14 sec cycle time. The only way to get a 7 sec cycle is to get a unit that attaches to a tractor.

Is it safe to assume that this is some safety limitation in place on the commercial units with a 14 sec cycle, or is it to do with cost and GPM?

What I would like, and correct me if I am wrong, is a unit that is powerful enough to split 20" rounds but also cycle in the 7 sec range? Is that feasible?

While I do have a very basic understanding of hydraulics I am not sure if something in the line of an auto-cycler control is possible. i.e. Hit the lever once and the piston completes both strokes. In my limited search I have not found such a control. Then again with the limited knowledge of hydraulics, I might of been staring at such already.

 

[hanko]

Currently own a 35 ton commercial unit, but thinking of making my own just rather then improving on this one (log lift, table, etc).

My question is regarding cycle time. It seems like all the commercial units that I have studied all have a 14 sec cycle time. The only way to get a 7 sec cycle is to get a unit that attaches to a tractor.

Is it safe to assume that this is some safety limitation in place on the commercial units with a 14 sec cycle, or is it to do with cost and GPM?

What I would like, and correct me if I am wrong, is a unit that is powerful enough to split 20" rounds but also cycle in the 7 sec range? Is that feasible?

While I do have a very basic understanding of hydraulics I am not sure if something in the line of an auto-cycler control is possible. i.e. Hit the lever once and the piston completes both strokes. In my limited search I have not found such a control. Then again with the limited knowledge of hydraulics, I might of been staring at such already.

I think my timberwolf TW 5 cycles in 8 sec.

 

[chrispy6822]

Well I just got through searching on the forums. Lots of great info. At least I got the auto-cycle part pretty much figured out.

Still stuck on the cycle time. To me it seems to be a function of GPM versus cylinder size, but is there a formula to estimate cycle time?

Or would it be just as easy to copy specs from say Timberwolf?

Like Hanko mentioned with his TW-6 at 8 seconds or the TW-6FC with 6 seconds.

Specs for the TW-6FC are

Splitting Tons 20 tons
Pump 22 GPM
Hydraulic Tank Capacity 15 gallons
Max. Log Length 26 inches
Cylinder Size 24 x 4 x 2
Cycle Time 6 seconds


I imagine that the cycle time comes from two factors, GPM of the pump and cylinder size??

 

[chrispy6822]

I think my timberwolf TW 5 cycles in 8 sec.

According to the webiste specs the TW-5 is 10 seconds and the TW-5FC is 6 seconds.

 

[BlueRidgeMark]

Still stuck on the cycle time. To me it seems to be a function of GPM versus cylinder size, but is there a formula to estimate cycle time?

...

I imagine that the cycle time comes from two factors, GPM of the pump and cylinder size??

Yeah, I think so. You could figure it out. You'd have to calculate how much volume (gallons) of fluid the cylinder holds, then figure how long it takes to fill it at whatever GPM your pump puts out, times two for a complete cycle.

That would give an UNLOADED cycle time, I think. How much that would slow down when splitting would probably be complex calculation affected by the HP of the engine...

I think...

 

[drmiller100]

you have the formula correct. cylinder size, gpm, rod diameter, and stroke length determine cycle time.

4 inch for me has been a great plenty.

i have a 25 horse vertical shaft engine, wtih a 10/20 gpm pump. so, at low pressure high speed, i'm pumping 30 gpm, which actually splits most logs. when she needs to, she kicks down to 10 gpm to get the 3000 psi.

I think it cycles around 7 seconds.

my autocycle was accomplished with a double detent valve, piece of angle iron, bungy cord, and tie down strap.

Is it safe? as long as follow the magic rule. When you hit the start split lever, you NEVER put your hands near the round.

 

[chrispy6822]

I'd love to see a pic of your autocycle set up. I think the idea of a mechanical auto cycle has a lot of merit.

I found a great link on the internet with someone describing their auto-cycle. Most intriguing was the mechanical limit switch ( so the ram would not retract all the way). Seems simple enough and a great benefit in cycle times.

Link was working a couple of minutes ago, but seems to be down for a few. I am sure it will come back up.

http://www.tractorbynet.com/forums/build-yourself/50076-wood-splitter-auto-cycle.html

 

[kevin j]

I've tried in the past to insert a page of basic forumala for force, speed and hp, but this box is only half as wide as a normal .doc Word file page.

I've tried all sorts of reduction and text sizes, both in Word and in the reply box here, but always messed up for word wrap and thus worthless.

Anyone know how to reduce and display say a 6 inch wide .doc page into this box?

k

 

[triptester]

This site has calculators for hydraulics.

cycle times
tonnage
others


http://www.baumhydraulics.com/pages.php?pageid=4

 

[chrispy6822]

I've tried in the past to insert a page of basic forumala for force, speed and hp, but this box is only half as wide as a normal .doc Word file page.

I've tried all sorts of reduction and text sizes, both in Word and in the reply box here, but always messed up for word wrap and thus worthless.

Anyone know how to reduce and display say a 6 inch wide .doc page into this box?

k

Kevin,

If you can and have some form of graphics editing program just do a screen capture using ctrl-alt-prtsct. This would copy a picture of MS word to your clipboard. Paste it into your graphics program.

Save for that, send me the file and I can do it in a snap for ya.

 

[chrispy6822]

This site has calculators for hydraulics.

cycle times
tonnage
others


http://www.baumhydraulics.com/pages.php?pageid=4

Bingo. That is what I was looking for. Thanks for sharing.