Another Log Splitter Question

   / Another Log Splitter Question #1  

Inter674

New member
Joined
Apr 3, 2012
Messages
5
Location
Pelverata Tasmania
Tractor
Massey
Hi I am new here but have often viewed the great advice given regarding hydraulics.

I am building a wood processor - I'll post some pics later. It has twin Cassapa 20gpm open centre tandem pumps, a 30hp Kubota diesel, a lifting table/ram/spool, a log splitter spool feeding a 4"x2"x18" cylinder and a hydraulic motored 12' conveyor attached.

Question, how to power the whole circuit:confused:

I'm thinking of combining the pump outflows and feeding these first to a 2 spool valve block with PB facility - one spool for the lifting table (with in-line one-way reducer) and the other a motor control spool feeding perhaps a priority valve for conveyor speed control and then taking the PB to feed the detent splitter valve. The hyd motor will run all the time.

Will the motor (an axial piston type running at low revs) rob the splitter valve too much or conversly, will the splitter valve opening stall the motor?? I don't want to get into flow dividers as they will cause heat build up, I think.

Any thoughts or advice are most welcome
 
   / Another Log Splitter Question #2  
It will take about 41 HP to run a single 20 GPM pump at 3000 psi.

If you use a motor spool in the same valve, with a log splitter, you will share the fluid, when the other spool is activated, thus reducing the speed. Not a big deal on a conveyor.

If you want the hyd motor to run at a constant speed, you will need a splitter or flow divider.

If you have two pumps, use a solenoid operated motor spool valve, with relief on one of the pumps.

Don't think you have enough HP for both pumps, and the 30 HP engine will stall out under load.

Your 30 HP will do a 14.6 GPM pump at 3000 psi.
 
   / Another Log Splitter Question
  • Thread Starter
#3  
Many thanks for the prompt reply.

Yes the HP may be a bit shallow for 20gpm but I guess the ram is not going to take that much under load being only a 4"dia with 2" rod. I toyed with a 4.5 or a 5" ram but was advised against it due to HP requirements exceeding my 'free' Kubota motor. The wood we have in Tas is rated mid-strength and most splitters here use this size ram quite sucessfully.

Yes there are 2 pumps so a solonoid operated motor spool valve is a possibility but could be quite expensive I think:(

Given the splitter ram spool will be operated from the PB on the combined first valve block (ie., the one operating (occasionally) the lifter table and (constantly) the conveyor motor), do you think operating the splitter valve will stall out the conveyor motor completely because (without a divider) all the supply will flow to the splitter ram?

:mad: PB arrangements always befuddle me in terms of how the oil actually flows in a PB arrangement.
 
   / Another Log Splitter Question #4  
PB means power beyond or a supply for fluid for downstream operation. The tank port was not designed for high pressure operation. If all valves have PB, then the PB from all valves are connected in series, as in PB to IN port, and so on. The last valve does not need PB as it is going to tank.

A solenoid motor valve would only be around $150 and you need the subplate

Surplus Center - 12 VDC 10 GPM OC MOTOR SPOOL SOLENOID VALVE
Surplus Center - 1 STATION DO3 SUBPLATE OPEN CENTER

As far as stalling out the motor, what it will do is take part of the fluid and slow down the hyd motor.

If you want constant speed on the conveyor, you need a separate hyd supply or a splitter/divider.
 
   / Another Log Splitter Question
  • Thread Starter
#6  
..but maybe not if when operated, the motor spool closes off the PB. So it would seem a splitter is the best option:)
 
   / Another Log Splitter Question #8  
You could also use an open center valve not a tandem center valve for motor control.

Tandem center spools lock the cyl or motor, and are not used for hyd motor circuits.

You probably want a motor spool valve with detents, to lock the motor on.
 
 
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