hydraulics help needed

[Partsman2]

I agree with Ron. You need to be running in series on an open center system. You go from the pump to the inlet port on the ram cylinder valve and from the outlet on the ram valve to the inlet on the log lift valve. Then from the outlet on that valve to the sump.

There is no reason to try and run them parellel as you don't need to run both at the same time. The fluid is by-passing and taking the path of least resistance. This is why your cycle times are so slow.

This is my opinion for what that's worth.

 

[kennyd]

That picture is worth a thousand words to me...
Your valves a definitely in parallel, it is still splitting because only so much fluid can go back through the proportioning valve.

IMHO, your best bet is to remove the proportioning valve altogether, plumb as stated above:
Pump OUT to
Ram valve IN
Ram valve OUT to
Lift valve IN
Lift valve OUT to
Filter then to the tank.

If the lift moves to fast as you stated in the original post, the just use a flow restrictor on the work ports (the kind that has a small orifice to slow the flow of fluid) as they are very inexpensive.

 

[MMM]

It isn't really a parallel circuit with seperate flows coming off divider (That's why they're built). It will flow 90% and 10% no matter the load and won't lose flow through divider.
You shouldn't just run 2 valves in series without 1st being rated for backpressure produced by 2nd, unless PB sleeve is installed. Might could adjust relief for 2nd valve under backpressure limit for 1st valve if it'll still do the work at lower pressure.
The restrictors will work in place of adjustable spool travel valve.
The chatter you experience is most likely due to not being pressure compensated divider

 

[jimmysisson]

To complicate this a little more, when I move the proportioning valve all the way to the ram flow side, the ram is only slightly faster, probably about what it was before I added the second valve for the lift. I think MMM is right about the prop. valve separating the flows. If the lift valve is centered, oil might dump through the return but how would that affect the flow to the ram valve? I just don't know much about hydraulics. Does anyone think the shutoff in the return could be restricting the flow TO the pump? Here's a pic of the pump side of this clunker. Labels might be hard to read. Thanks, Jim

 

[MMM]

You just got your 10% back and if that's not satisfactory, the only other thing you can do is try the thinner oil before going to larger displacement pump, (unless engine isn't running at max rpms).
Anyway for fastest cycle, you want full flow through splitter valve 1st.
Divide flow or restrict lift cyl 2nd, and you should have PB to do this to avoid blowing seals,... or turn down relief on lift valve to allowable level (wouldn't hurt to try and see if it'll still lift a log).
The PB sleeve is usually 20 to 30 bucks if your valve will accept one and restrictors are couple bucks.
I can't make out text on pic, but what shutoff in return?

 

[jimmysisson]

It's right above the tin can that catches most of the drips from the shutoff. It makes me think, since I got this this splitter (ten years or so ago), and modified the hydraulics a couple of times I never found a strainer from the tank. Maybe there is one above the bottom fitting in the tank where the return line goes in? A plugged screen there might explain a lot. Probably wouldn't hurt to change the fluid again and find out. I hope (and hope not for prides sake) it's not something that stupid. Maybe there isn't a strainer there, since there is one on the filler neck. I'll find out in a day or two.
Jim

 

[RonMar]

</font><font color="blue" class="small">( Ron.. I've got a question.. if he had the valves in parallel, and one was open.. ( open flow to tank ).to tank and the other was powering the splitter cyl.. as soon as the cyl loaded up.. wouldn't ALL the oil divert to the least resistance.. and simply flow to the tank via the other valve.. and not splitting the wood at all?

Soundguy )</font>

Soundguy, I wasn't sure where exactly the diverter/flow regulator he mentioned was in the circuit but I assumed it was how he split the flow to the valves and it was providing the resistance. That's why I suggested a picture

 

[bugstruck]

I think your getting good advice here. But before I got too carried away, I'd take the supply line to the ram cylinder valve and plumb it direct from the pump (eliminate the proportioning valve for a test). No need to change anything else to run that test, except maybe plugging the proportioning valve open port (where you disconnected ram valve supply), in the event you get some return backflow from the lift side of the circuit. You may have something going on with the pump or fluid that no amount of replumbing will fix. If it works OK in the test configuration, then correct the plumbing for a series arrangement and do a flow restrictor as others have mentioned for the lift valve. Or change that proportioning valve to a diverter. But that would force you to select one circuit or the other before you could activate it. /forums/images/graemlins/frown.gif Nah that's tooooooooo much inconvenience.

HTH

 

[MMM]

That's suction hose that valve is on. The strainer should be on suction (big one on pump) hose bulkhead fitting inside tank and not in the line.

Might also be possible inner core of suction hose is collapsing.

There is a formula for horsepower requirements, if you know cubic in/rev( for both stages), your relief setting pressure, rpms, and efficiency (usually.85 or so). I think it would work for 2 stage pump, but never tried it.

 

[jimmysisson]

THanks to everyone for their help. The foot of snow yesterday just put the splitter problem to bed for a couple months. I'll be checking for strainers, collapsed hoses, bypassing the proportioning valve, etc. when I get back to it. I appreciate all the input. Jim