Homebuilt Splitter - Seems Slow...

[Stew182]

Hi all, great site, lots of useful info here!

New guy here. I need some help with my homebuilt wood splitter I recently finished.

My splitter has the following:

-11HP Briggs & Stratton
-Haldex 16GPM 2-stage pump
-4" cylinder with 24" stroke
-Gresen (parker) valve, 16GPM max, 2000 PSI max, 3/4" inlet/outlet, 1/2" work ports, spring return to center
-1/2" hoses from pump to valve, and valve to cylinder
-3/4" return hose


My problem is that the cylinder extends alot slower than I thought it should.

According to my calculations ( which might be wrong ), the cylinder should extend fully in about 4-5 seconds @ 16GPM, but it is taking around 10 seconds.

Could it be my valve (16GPM max) , or possibly the small 1/2" hose running from the pump to the valve ?

It seems to work great, except for being too slow for me.

Any ideas as to why it is extending this slow ??

Thanks ,
Allan.

 

[CaseyForrest]

Lets see, I have a 16gpm pump and a 4.5" cylinder. Probably takes about 10 seconds, maybe 9 to fully extend. You may have some restriction in your valve. You are working at the upper limit of its GPM.

I dont think its in your hoses, if you have 1/2 coming out of your pump, then thats what its designed to use. I use 1/2 from pump to valve, 1/2 to the cylinder, and 3/4 back to the tank.

Id say get a better valve, one that will handle 25gpm, has an adjustable relief (2000 is pretty low) and a detent.

How are you figuring your ram speed?

 

[mga]

or possibly the small 1/2" hose running from the pump to the valve ?

you didn't mention if there was a reduction at the pump port or not.

is the pump port 1/2"

 

[Stew182]

Thanks for the help Casey. I figured it must be the valve, or the 1/2" hose running from the pump to valve.

Lets see, I have a 16gpm pump and a 4.5" cylinder. Probably takes about 10 seconds, maybe 9 to fully extend. You may have some restriction in your valve. You are working at the upper limit of its GPM.

I dont think its in your hoses, if you have 1/2 coming out of your pump, then thats what its designed to use. I use 1/2 from pump to valve, 1/2 to the cylinder, and 3/4 back to the tank.

Id say get a better valve, one that will handle 25gpm, has an adjustable relief (2000 is pretty low) and a detent.

How are you figuring your ram speed?

Casey, I am figuring my ram speed by cylinder volume. The cylinder volume is 1.3 gal.

16GPM divided by 60 seconds = 0.2666 gal. per second.
1.3 gal. divided by 0.2666 = 4.88 seconds.

I was thinking of buying a Prince LS3000 valve. Is this a good reliable valve?
It is 25GPM , adjustable relief up to 2750PSI , and return kick-off.
This is the only valve I can find in my area.

 

[Stew182]

or possibly the small 1/2" hose running from the pump to the valve ?

you didn't mention if there was a reduction at the pump port or not.

is the pump port 1/2"

Thanks for the reply mga, my pump has a 1/2"NPT outlet, and I am using a 1/2" hose from pump to valve.

Would there be any flow increase if I changed this hose to 3/4" ?
I was thinking it wont make much difference, with a 1/2" outlet port on the pump.

 

[mga]

i've always used this site to figure ram speed.....

http://www.baumhydraulics.com/cyl_speed.htm

 

[CaseyForrest]

Thanks for the help Casey. I figured it must be the valve, or the 1/2" hose running from the pump to valve.



Casey, I am figuring my ram speed by cylinder volume. The cylinder volume is 1.3 gal.

16GPM divided by 60 seconds = 0.2666 gal. per second.
1.3 gal. divided by 0.2666 = 4.88 seconds.

I was thinking of buying a Prince LS3000 valve. Is this a good reliable valve?
It is 25GPM , adjustable relief up to 2750PSI , and return kick-off.
This is the only valve I can find in my area.

Thats the same valve I have. Easy to use and easy to adjust.

I may have been off with my times, I punched up that link that mga posted, and my times seem a little closer that what the calc suggested.

I don't think going to 3/4 out of your pump will help. Get yourself a new valve, and eliminate all unnecessary fittings, mainly 90's. Also, eliminate any unnecessary hose length.

 

[Stew182]

I have 90 degree fittings on all my high pressure hoses, except for the pump outlet.

Do you think these fittings restrict the flow THAT much, or is the majority of restriction coming from my valve ? (valve is 16GPM max)

I dont really want to have straight fittings, and have my hoses sticking out everywhere. I was trying to keep it as compact as possible.

Does anybody have a similar setup as mine, with a 16GPM pump, 4" cylinder with 24" stroke, and 1/2"hoses with 90 degree fittings ?

Do you think the Prince LS3000 valve (25GPM) will take about 4 or 5 seconds off of the extension time ?

I am just trying to find out the time it 'should' take for my cylinder to extend with no load .


Thanks again
Allan.

 

[CaseyForrest]

I forget the exact number of pressure loss in length of hose and fittings. Im not saying you need to eliminate all your 90's, just if you dont need one where you have it, ...thats all.

BUT, pressure loss in the fittings and hoses isnt really an issue since hose lengths are so short, I guess I shouldnt have brought it up!!!!!

 

[mga]

i have the prince 3000 on my splitter and i'm happy with it...especially the return detent.

 

[CaseyForrest]

Here is a pic of my set-up.

And an action shot.

Set-up is Honda 8 horse, 16gpm pump, 19 gallon tank, prince 3000 valve, prince 3000 psi cylinder, 4.5" x 24". All 1/2" hoses except for the return which is 3/4" and suction is 1". You see I screwed my valve right into the clylinder port. No need for fittings there, and no need to add a support to affix the valve. Im guessing ive got about a 12 second total cycle time, and rarely need to run the engine above half throttle.

 

[olyman]

casey--neat idea what to mount it all to--surely you have it fixed--so when ready to move--just start up old trac--and move it??????????:greenchainsaw: :greenchainsaw: :greenchainsaw:

 

[CaseyForrest]

casey--neat idea what to mount it all to--surely you have it fixed--so when ready to move--just start up old trac--and move it??????????:greenchainsaw: :greenchainsaw: :greenchainsaw:

Well, not yet!!! The tranny is still in it with a pulley on it.....Just need to match up a hydraulic motor and valve and it will be self propelled. Right now I have a pull handle in it, works well for me now.

 

[Stew182]

So do you guys think I will get faster cylinder extension speeds with the Prince valve (25GPM) than with the valve I have now (16GPM) ??

I would hate to waste 100 bucks or so for a new Prince valve, and not notice any improvement in ram speed.

Here's a couple pics of my splitter:

View attachment 39818

View attachment 39819

View attachment 39820

View attachment 39821


It turned out fairly well for my first splitter. It's a little heavier on the hitch end than I wanted, but I can still lift it and move it around. I also wanted a thicker I-beam than what I have , but it was the only thing I could find at the machine shop I work at.
The boss at work gave me all the steel I needed to make it, including the cylinder I fabricated, motor mount, pump mount, ram, wedge, I-beam, hydraulic tank, axle, etc.
That really saved me alot of cash!!

So should I see an improvement in cylinder speed with the Prince valve, or will I be wasting my money??

 

[CaseyForrest]

Nice Fab work there!!!

Hard to tell if you would notice a difference. Other than finding someone who knows about hydraulics, its trial and error.

Do you have a pressure gauge between your pump and valve? Maybe your pump is not running both stages when its under 600psi....

 

[Stew182]

Nice Fab work there!!!

Hard to tell if you would notice a difference. Other than finding someone who knows about hydraulics, its trial and error.

Do you have a pressure gauge between your pump and valve? Maybe your pump is not running both stages when its under 600psi....

Yes I have a pressure gauge mounted on the back end of the cylinder.
The pump must be working in both stages, because I figured when the pump is on the high flow/ low pressure stage (16GPM), it should take around 5 seconds to extend the cylinder. When the pump unloads to low flow/high pressure (4GPM), it should take around 15 seconds to extend.
Mine is taking around 9-10 seconds to extend, with no load.

I am not sure how these pumps switch from high to low when the unloader PSI setting is reached, maybe my pump is kind of "stuck in between" high and low.

Are there any good sites on hydraulics with the kind of info I am looking for ?

I cant seem to find any.

Thanks again,
Allan

 

[aokpops]

my splitter seems slow to . I was thinking of using a lighter oil to speed it up . or tranny fluid. is this possible ?

 

[aokpops]

my splitter seems slow to . I was thinking of using a lighter oil to speed it up . or tranny fluid. is this possible ?

 

[Patrick62]

I'll toss in my $0.02 worth...

Trans fluid will work fine, some splitters specify it.

As for speed of ram (that is a great link to Baum, thx! ) I have worked on several splitters up here. I have not measured them, but:

My critter-splittter uses a 16gpm pump, and a 5" cylinder. 1/2 hoses, and a few 90's tossed in. Engine is a 15hp Kohler (overkill :hmm3grin2orange: ) since the littler engines were struggling. Speed is okay, maybe a tad slow for some folks.

Another machine around here is using a 13.5gpm on a 4" ram. It feels faster than the critter-splitter. 6.5 Briggs for a engine. This one has 4 90deg fittings on it. No problem.

Another one is using a 13.5 gpm on a 3 1/2 cylinder. This thing boogies. Engine is a mil-spec antique.

Another machine is a 4" cylinder with a 11gpm pump, it is a tad slow, but with only a 18" stroke it is acceptable in use.

All valves are the common single, or double detent valves. 25gpm rated.
Another factoid, we do not run the engines "full out". Quieter, more fuel efficient, longer life span. Dis-advantage is that the gpm is actually only about 3/4 of rated flow. All of the hoses on these things are 1/2 variety. Probably marginal at 16gpm, but extra power makes it work.

I doubt that the valve is much of a restriction. It is possible that the pump has issues. Perhaps the second smaller stage is broken, and not pumping? Only other thing that would make it slow(er) is the engine not up to speed.

-Pat

 

[pbtree]

Nice work dude - that is a nice looking unit for sure!