Hydraulic cylinder sizing ??

   / Hydraulic cylinder sizing ?? #1  

hr3

Veteran Member
Joined
Oct 18, 2008
Messages
1,208
Location
Mid. Coast Maine
Tractor
7610 hst
I'm trying to make my wife's log splitter easier to use.. Right now I'm putting new tables on both sides and would like to add a lift table and stabilizer leg to offset the weight on the lift side,, Stroke collapsed is about 18" on both.. I'm wondering what diameter I should go with,, The splitter is a 21 ton "White Outdoor" 6.5 hp motor..

Also what would you use for valves "on the cheep" to control them ??? Any help would be appreciated ..
 
   / Hydraulic cylinder sizing ?? #2  
I'm trying to make my wife's log splitter easier to use.. Right now I'm putting new tables on both sides and would like to add a lift table and stabilizer leg to offset the weight on the lift side,, Stroke collapsed is about 18" on both.. I'm wondering what diameter I should go with,, The splitter is a 21 ton "White Outdoor" 6.5 hp motor..

Also what would you use for valves "on the cheep" to control them ??? Any help would be appreciated ..

You need a valve with PB as the first valve in the flow path.

Here is a 2 spool valve with PB that would work well as a log lift and perhaps a blade lift.

Surplus Center - 2 SPOOL 8 GPM PRINCE MB21BB5C1 DA VALVE

You would have the pump feed the valve with PB, and the PB valve with PB adapter installed, feed the log splitter valve.

This valve can replace your current log splitter valve.

Surplus Center - 2 SPOOL 25 GPM PRINCE LOG SPLITTER/LIFTER VALVE

This valve can operate as a log splitter valve and as a log lift valve in one one valve. It also has PB for whatever you want to add.
 
   / Hydraulic cylinder sizing ??
  • Thread Starter
#3  
Thanks' JJ But what do you think about the size for the cylinder for the lift and the stabilizer leg ???
 
   / Hydraulic cylinder sizing ?? #4  
2 to 3 in cyl bore for both.
 

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   / Hydraulic cylinder sizing ??
  • Thread Starter
#5  
The first valve you list would go before the existing splitter valve ?? If so is the 8 gal. per min. going to be enough to feed the splitter valve ??.. Or doesn't it work that way...
 
   / Hydraulic cylinder sizing ?? #7  
if your tractor is a Kubota B7610 hst

\Hydraulics:
Type: open center
Valves: 1
Pump flow: 4.4 gpm [16.7 lpm]
Total flow: 7 gpm [26.5 lpm]
Steering flow: 2.6 gpm [9.8 lpm]

The two spool valve with PB mounted first should work, as your tractor only puts out an implement flow of 4.4 GPM

Your log splitter valve is capable of using about 25 to 30 GPM's.

That cyl should work fine if the open and closed length are good for you.
 
   / Hydraulic cylinder sizing ??
  • Thread Starter
#8  
:confused: This isn't for my tractor,, It's for my wife's log splitter,, Like it says above it's a "White Outdoor " 6.5 HP.. This has nothing to do with my tractor...????????
 
   / Hydraulic cylinder sizing ?? #9  
Ok, now I understand, I missed the 6.5 engine.

What is the GPM rating on the pump on the 6.5 engine?

If it is higher than the 8 GPM valve, then look and find a valve with PB that will handle the flow of the pump. Install it first in line and make sure the filter can handle the hyd flow.

Maybe this one.

http://www.surpluscenter.com/item.asp?item=9-7976&catname=hydraulic
 
   / Hydraulic cylinder sizing ?? #10  
I would use a 2" cylinder; that's about 3sq in of piston face area, so a 2500 psi system produces a force of 7,500 pounds to extend the cylinder. I don't know exactly how you plan to mount it, so I don't know the shortest moment arm through which it will be acting. But if the cylinder can extend a full 16 inches surely the moment arm will not be less than 6", so even if your table extends 36" out from the splitter beam, and the log is at the very end of the table (unlikely) you will still have a lifting force of 1/6 of 7,500 pounds when the table is up to horizontal, which is 1,250 pounds. Take off 100 pounds for the table, that still leaves 1,150 pounds for the log. If your wife can get a 1,150 pound log to the splitter she doesn't need a lift table; in fact, she doesn't even need a splitter.
 
 
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