Advanced hydraulics dual pump splitter build diesel mower conversion

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To start I am wondering if I will have enough horse power to run a dual single stage pumps. One 1.5" inlet two 7/8 outputs. Each pump is rate for 20 gpm at 3500 psi at 3000 rpm. One pump for main pusher and other for 4 way and other stuff. Running a 4.5" cylinder with 3.5" shaft 30" stroke. I have the dump valve and 3/4 lines on main cylinder. To much flow to use a unloading valve with one of the pumps. With estimated efficiency of 85% for pump will it work or stall engine.

Engine 34 hp Kubota Diesel non turbo.

I am trying to copy the Built-Rite 24 HPWS-D splitter by using a old fairway mower engine. The mower was wore out but motor still has life.

Plan is to finish by spring with the build.

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Sam, its going to take about 45hp just to pull one section of that pump at 3500psi, so I would say if your going to run those pressures on both pumps, at the same time, you are way under powered. In real life, you most likely are not going to be pulling that kind of pressure with both pumps at the same time. About the most pressure you can build with just one pump section is about 3000psi and thats pushing the limits of you engine. Especially since even though the other section might not be making pressure, you will still have residual power drag just moving the fluid. I would think with a 4.5in cyl, your pump probably wouldnt need 3000psi to split the majority of the wood you might encounter. I suspect for the other functions, you probably wouldnt be splitting and adjusting the wedge or traveling at the same time as splitting, nor would you need 3000psi of pressure to accomplish those task. Also 20gpm is going to make that wedge adjusting cyl mighty fast. Anyways, I think your pump motor combo will work, as long as you realize your machine will split the majority of the wood you have without bogging the engine, but you might encounter a log ever now and then that you wont have the hp to process. Set your relief pressures to where it might bogg down the engine occasionally but not kill the engine and live with it, or find a bigger engine.
 
Set it at 2300 PSI and be done. Only way it won't go through is if it's a super knotty piece and you are trying to do right down the middle. Take a small piece off of it and then resplit. The efficiency of the wedge will go through 99% of what you put on the beam. I just ran mine both days this past weekend, and I think I only went to the lower stage 3 times.

Hope to see it on or before May 16th, 2016!! Keep up the good work Doug!!
 
Sam, its going to take about 45hp just to pull one section of that pump at 3500psi, so I would say if your going to run those pressures on both pumps, at the same time, you are way under powered. In real life, you most likely are not going to be pulling that kind of pressure with both pumps at the same time. About the most pressure you can build with just one pump section is about 3000psi and thats pushing the limits of you engine. Especially since even though the other section might not be making pressure, you will still have residual power drag just moving the fluid. I would think with a 4.5in cyl, your pump probably wouldnt need 3000psi to split the majority of the wood you might encounter. I suspect for the other functions, you probably wouldnt be splitting and adjusting the wedge or traveling at the same time as splitting, nor would you need 3000psi of pressure to accomplish those task. Also 20gpm is going to make that wedge adjusting cyl mighty fast. Anyways, I think your pump motor combo will work, as long as you realize your machine will split the majority of the wood you have without bogging the engine, but you might encounter a log ever now and then that you wont have the hp to process. Set your relief pressures to where it might bogg down the engine occasionally but not kill the engine and live with it, or find a bigger engine.


Thanks for the input. From my calculation I was thinking it should handle most of the splitting. I have bigger TM pro skid steer splitters for difficult looking pieces. But I have gotten what looks like easy 14" elm and turned out to be the worst stuff ever. Knots in the middle with lots of twisting grains.

Set it at 2300 PSI and be done. Only way it won't go through is if it's a super knotty piece and you are trying to do right down the middle. Take a small piece off of it and then resplit. The efficiency of the wedge will go through 99% of what you put on the beam. I just ran mine both days this past weekend, and I think I only went to the lower stage 3 times.

Hope to see it on or before May 16th, 2016!! Keep up the good work Doug!!

Plan is Iowa spring GTG for testing.
 
I bet a double stage 28gpm pump would work way better.

To power other accessories I think it would be neat to have a complete second hydraulic system......like an automotive power steering pump driven by a fan belt......and use the main hydraulic tank. It sure seems better than flow dividers/reducers, etc. for low volumes. Just a thought.
 
I bet a double stage 28gpm pump would work way better.

To power other accessories I think it would be neat to have a complete second hydraulic system......like an automotive power steering pump driven by a fan belt......and use the main hydraulic tank. It sure seems better than flow dividers/reducers, etc. for low volumes. Just a thought.

Good idea using a power steering pump for extras. I got a good deal on this pump so if it doesn't work out I will try another setup. Just doing the math before I put it all together.

Engineers like to doing the math first. I just don't know much of the hydraulic math yet. Do more of the electrical and chemical side of things.
 
Del, a 28gpm two stage pump would certainly work and lower hp requirement, but I bet it would have a slower cycle time than the 20gpm single stage pump in hard to split stuff. In anything taking 900psi or less to split, the 28gpm 2stage pump would shine, but if the wood is the least bit tuff to split, I think the single stage pump will out perform as far as speed. Grimmy has the right ideal, I know I was splitting very notty, large dia, whiteoak 4 ways with my 4in bore splitter and it would work a team of mules to death keeping it fed. I had a 14gpm single stage pump on that machine and a 25hp kholer gas engine.

Like you, I think he might have a little to much flow for the other circuits.
 
Mudd, I've been running a 28gpm two stage for a little over 25 years now on an 18hp Briggs IC and a 5inch cylinder. It's works out pretty good and stays in high gear almost all of the time. My splitter uses a dual locking valve and I've rigged up an auto return function that has worked well now for the past two years. It's great to put a piece on and go get the next. Auto return rocks. Forward locking of course is something to be very careful with but for 25 years now no pinches.....knock on wood!

I've not seen a thing you've posted that I'd take issue with.
 
Good idea using a power steering pump for extras. I got a good deal on this pump so if it doesn't work out I will try another setup. Just doing the math before I put it all together.

Engineers like to doing the math first. I just don't know much of the hydraulic math yet. Do more of the electrical and chemical side of things.
Well, you have your pump and with proper valveing, it would make a heck of a splitter pump. I think I would try to find out the hyd requirements of your drive system and match the accessory hyd circuits to those specs. A log lift and wedge lift wont take much pressure or flow. I used to have, and might still do somewhere, a front drive plate for a kubota engine. It bolts to the front crankshaft. If you could get a small pump with reverse rotation to pull the drive system, I'll donate the pump adapter and you can make a separate hyd system just for the little pump. Just thinking it might be cheaper to do a little pump swapping than trying to control flows on the double pump. Just something for you to think about. I'll look for the adapter when I head back to the shop.
 
Doesn't a flow divider load the engine at all times....even when the circuit is not doing any work?

Don't know how it works. It is a flow regular of some type. I think it would not load the system to much. I was guessing 9 gpm would be slow enough for 4 way and other stuff.

From Surplus Center website.

FIXED FLOW PRIORITY DIVIDER WITH PRIORITY PRESSURE RELIEF
Brand new Prince model RD-405R-9 fixed flow priority divider valve. Use to split pump output into a fixed, priority flow and a balance flow for use in the primary hydraulic circuit. Pressure relief valve on the priority port is factory preset to 1,500 PSI.

SPECIFICATIONS
  • 9 GPM fixed priority flow
  • Adj. relief valve set to 1,500 PSI
  • 30 GPM Max. input flow
  • 3,000 PSI Max.
  • 3/4" NPT inlet & excess flow ports
  • 1/2" NPT priority port
  • 3/8" NPT relief port
  • Overall size 4-3/4" x 4-1/8" x 1-3/4"
  • Shpg. 9 lbs.
 
Lets look at how your going to need to plumb that priority control valve. It is pressure compensated so flow should remain constant reqardless of pressure requirements of secondary circuit. You will need a line in, two lines out, (one for priority and one for secondary flow) as well as a return line for any flows over the relief, and you have a ton of flow dumping to tank thru the secondary circuit. Lots of plumbing=$$$. The valve itself is expensive and your wasting a lot of power with the secondary oil flows. Will it work, yes, but probably not the best combination of parts.
 
I overlooked all the plumbing for the flow valve. Great. I have already been to Surplus Center three times. FYI it's not far off the Interstate. I get near there for work a few times a year.

Wondering if I should be looking for a hydraulic machine to make hoses. Ouch.
 
Found the kubota front pump drive if you decide you need it. Flange looks to be about 6in dia with a 5 hole bolt pattern. Shaft size I am pretty sure is 1 7/16". PM me if you want it.
 

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I'd have to pull out my books, but I believe the pump on my processor's splitter is about 30gpm and my 35hp Kubota handles it fine. Relief set to 3000psi.

It's a stack of Permco pumps, similar to the pics.
 

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