DIY Hydraulic Splitter - Thoughts and Questions

[CombatChris]

So... I love the Fiskars. I love to swing it. I love sledge and wedge. The ring of the steel, the primal feeling of splitting something open with some whacks. But... I also want to move fast. I want to be able to quickly split gnarly, not just nice and neat rounds which will be found when scrounging. I want to be able to go through sweet gum faster than the present pace...

So I'm thinking about a splitter. And in doing this thinking, I am considering DIY. It sounds simple enough.

Get:

engine/motor
hydraulic pump
piston
fixed point or wedge
a frame to mount it on
a reservoir
tubing to make it all go

I know it's going to be a lot more work than just looking at it, and expecting it to put itself together, but here's what I'm considering.

ELECTRIC!! (cue dramatic music) I figure it should have less maintenance than a gas, lower operating costs, quieter, and field mobility isn't something I was going to shoot for.

So... in the realm of single phase motors (since I have ruled 3 phase out of the question) you can find, pretty reasonably, 10hp, ~3500rpm, 230v, motors for less than $400. 10hp should be plenty (right?) and if I'm doing my thinking and math right, I should have somewhere around 40 tons. Hear me out.

http://www.surpluscenter.com/Hydrau...r-Pumps/16-GPM-2-STAGE-HYD-PUMP-9-7503-16.axd

3000psi max, 3600rpm max.

http://www.baldor.com/products/deta...=2800-3600&winding=37WGX047&rating=40CMB-CONT

3450 rpm, 10hp, single phase, 230v (48 AMP) Obviously the cost of this specific motor breaks the budget, but similar specced motors can be had on ebay for much less.

If assuming the pump makes peak PSI @ peak RPM, then 3450 RPM would yield 2875 PSI. Should I go with a 6" diameter piston (and since I'm doing this, I'm going to go big or go home) that gives me ~28in^2.

( 28 x 2875 ) / 2000 = 40.25 tons of force. What WON'T that handle? I also figured I would have a remove-able splitting blade so that I can swap out a 't' shaped blade for quartering or a simple post for halving.


Well, Hearth? Am I crazy, or does this seem practical and doable? What's a glaring problem staring me in the face that I haven't seen? Yes, I know this will have to have some serious wiring and a heavy duty breaker just for it. Be glad I've ruled 3 phase out because I was going to get all mad-scientist with a 30hp motor.

 

[Applesister]

I give 5 star ratings to the mad scientists of the world. However...as soon as you convert the imput to your house to 3 phase you have big brother watching you. Like uping the fuel capacity of your private Jet. Or raising carrier pigeons or infrared blocking shingles on your roof. Like Lorenzo DeMedici Im a patron of the Arts and Sciences but personally prefer to remain Off Grid. Completely Off Grid means no reliance on fossel fuels of any kind, and despite my aversion I still embrace diesel power over electric. Electric useage is too easily monitored. lol

 

[CombatChris]

Yea, I'm not doing 3 phase for a good number of reasons.

The only thing I've yet to calculate is cycle time- which would really change if I went with the 6" or a smaller 5" diameter piston. A 5" piston would yield ~28 tons vs ~40, but it would cycle 40% faster. Hmmm.... 40% faster than what? Time to break out the calculator again.

 

[kennyp2339]

before you hook up that motor, consult with the power company. Your going to have to make sure the service from your xfmr pole to your weather head is large enough. You could do some damage to the xfmr, or create a brown out and prematurely kill your fridge and other sensitive electronics. The power company is going to want to know the type of motor, whether it has "soft starting " capabilities, and when the locked rotor current rate is.

 

[CombatChris]

Gotcha! That's good info. This will be at a site with new construction so I should be able to make sure it meets the needed specs when it's getting put in.

Really, a motor like that is shown @ 48 amps. If it draws another %20 on startup for a momentary spike, it's still less of a total load then running an electric dryer and electric range at the same time - each of those are in the ~30 amp range. But I for sure see what you're saying about a large initial draw. It'll be as isolated from the rest of the homestead as possible.

 

[CombatChris]

So say I go with a 5" diameter cylinder which had a 24" stroke. That would mean a 30 second stroke (on the pump's hi-pressure setting) and a 7.5 second return (on the pump's low pressure setting). If I went with a pump one size larger, the 22 GPM, then the power stroke would be 17 seconds with a return of 5 seconds. That's of course depending on how well a 10HP electric motor will work with a pump which calls for a 12HP gas motor.

If I went with the 6" bore, we would be looking at a 42 second stroke and 10.5 reuturn (with 16GPM pump) and 24 second stoke and 7 second return (with 22GPM pump).

 

[CombatChris]

Oh man, that's what I'm talking about.

http://www.precisepwr.com/pdfs/15HPSpec.pdf - 15 HP electric. The only thing is that I would have to gear up the RPM or find a pump with the same GPM which is designed for 1/2 the RPM. That'll handle 22GPM in a flash- and with a 5" piston this thing would fly. Even with a 6" piston it's not what I would call slow- and bringing 40 tons along with it.

 

[bobdog2o02]

I'm not an expert but I believe the 2 stage pumps run fast regardless of direction until pressure builds, then it runs the second stage and puts the PSI up.

 

[Jags]

Chris - I think you are getting a little wonky here. Couple of things:
First - you won't need anywhere near 10hp electric. A 5hp will pull that 16 gpm pump.
Second - if you use a 16 gpm pump you will NOT want to go any larger than 5" bore or it will travel at the speed of smell.
Third - Not sure how you calculated cycle times, but unless you have a 5" bore with a very large shaft, your in/out speeds aren't gonna change anywhere near as drastic as you have calculated.

I have a few splitters under my wings and few others here have built some really nice units. Ask away and we can get you on the proper path. Also - don't worry about trying to hit the 3000PSI max output. Your components will be pretty pricey to do that.

Take a look at the little splitter build I have in my sig. Might give you a couple of ideas of what to do or not do.

 

[CombatChris]

I'm not an expert but I believe the 2 stage pumps run fast regardless of direction until pressure builds, then it runs the second stage and puts the PSI up.

Yea, I'm just making the assumption that the motor will be in the 2nd stage on the way down the whole way and 1st stage on the way back up, just to simplify the math. Also, I just heard back from the hydraulics people. He says I would be fine using an electric motor as little as 6HP as long as I keep 3450RPM - with the 22GPM pump. I think the 10 will be fine, just fine, with a 22GPM. Bingo!

 

[CombatChris]

Chris - I think you are getting a little wonky here. Couple of things:
First - you won't need anywhere near 10hp electric. A 5hp will pull that 16 gpm pump.
Second - if you use a 16 gpm pump you will NOT want to go any larger than 5" bore or it will travel at the speed of smell.
Third - Not sure how you calculated cycle times, but unless you have a 5" bore with a very large shaft, your in/out speeds aren't gonna change anywhere near as drastic as you have calculated.

I have a few splitters under my wings and few others here have built some really nice units. Ask away and we can get you on the proper path. Also - don't worry about trying to hit the 3000PSI max output. Your components will be pretty pricey to do that.

Take a look at the little splitter build I have in my sig. Might give you a couple of ideas of what to do or not do.

Thanks for the heads up- I come to this forum to learn, and learn I have.

I did this for the calculations.

Area of a Circle in Inches^2 X length of cylinder in inches = cubic volume of the cylinder. Convert cubic inches into gallons, divide gallons per min rating of pump by gallons needing to be displaced by the cylinder.

I'm also considering a 22gpm pump, which will be much better suited to the 10HP motor. The 22gpm is at the 1st stage - it's 7 gpm on the 2nd stage. Which means the 2 gallons which would fit in a 5"x24" cylinder, can be filled in ~17 seconds @ 2nd stage, or just 5 seconds on the 1st stage. Or if I went with a 6", it would be filled in 24 seconds on 2nd stage and 7 seconds on 1st stage. On something soft or small, I would image it wouldn't even slow down...

 

[Jags]

Unless you plan on using a multi split wedge or box wedge you won't have any need for a 6" bore. My 5" bore at 2750psi will cut a 6" round of white oak in half - sideways.

Do you have a heavy welder and all that jazz to make this happen?

A 10hp electric will pull a 28gpm two stage splitter pump.

Edit: most splitters spend very little time in the high pressure stage. Taking a swag - probably less than 5-10%.

 

[CombatChris]

Unless you plan on using a multi split wedge or box wedge you won't have any need for a 6" bore. My 5" bore at 2750psi will cut a 6" round of white oak in half - sideways.

Do you have a heavy welder and all that jazz to make this happen?

A 10hp electric will pull a 28gpm two stage splitter pump.

Well when you put it that way....

And yes, I originally planned on getting a 4-way wedge for this at an adjustable height- or removable altogether for a simple vertical wedge. And I looked at the 28gpm pump- but it had the same 2nd stage speed of 7gpm, just a higher 1st stage when compared to the 22gpm.

I suppose it might be overkill- but if an 6, 8, or 10hp electric are all going to use 230v single phase, why not at least keep ones eyes open in the used market for the higher-power options? Less stress @ max power, less fatigue, more longevity was my thought process at least. I figured also since was going to be a long term project, it could be scrounged for very carefully. The end goal also would that this splitter be wheeled only as far as it's power would reach, and live within or work next to the eaves of a barn. Wood would come to it. I envision a log lift for this- I want to split 30" oak in 2 (or perhaps 4) without having to back out and have another go.

But you know, it could just be newbie fever. It would be I'm looking to bite off much more than I can chew. I dunno- that's why I'm asking.

 

[Jags]

A few more things...
Figure out what you want this thing to accomplish (you have a list going), then build to that. Going overkill is my style but I do try to keep it reasonable (even talked myself out of a 4 cylinder garden tractor)

The bigger the motor, the far more expensive it gets to wire (think starters, wire, breaker box, etc.). Fiddling with big motors is a lot different than the 1/2hp on your wire wheel. When you start dealing with starting caps as big as your arm things can get pricey.

You can build any darn thing you want to, but building a dump truck to handle a wheelbarrow job isn't always in your best interests.

 

[Jags]

One other suggestion - take a look at your favorite splitter on the market. One that has everything you want. It will help you pick out components that are compatible with your needs.

 

[CombatChris]

Here's I guess the list I'm forming.

Quiet - quieter than a gas, at least.
Fast- which I guess means a 22 or 28 gpm pump. If you think 10hp electric will run a 28gpm, then I'll go 6" bore. If it's good only for a 22gpm, then I'll go 5" bore.
1-shot splits - when using a single blade, I want to be able to split anything in a single pass. Sweetgum, gnarly knotted crotch oak, of any reasonable size I can get up there with a log lift.
4-blade option - I would like to be able to remove the single blade and put up a 4-way wedge, if I can figure out a good way of engineering the swap system.
Accessories - log lift and a table/tray to catch splits.

Question: Is there a way with the controls to set the default position to be in reverse? As in, when the ram is all the way back, it's stationary. I pull the lever to bring it forward, and when I simply let go of the lever, it defaults back to a reverse position and proceeds until the full-reverse is met. If that can be done, I would like that. That way I can be bringing up the next round or re-positioning for another split while it's getting back into position all by itself.

 

[Jags]

There really isn't a two way valve that will do that. You could spring return with a one way valve, but I would guess that you wouldn't like that. The detent valves that are usually found on splitters do a nice job. Instead of release/return you simply lock it into the return position and it will pop into neutral when it reaches the end of the return stroke.
10hp electric should run a 28gpm two stage pump.
If you are looking to build a hydro lift, you are gonna need multi lever controls. Might as well add another lever and design the 4 way to be raised and lowered with hydraulics.

 

[CombatChris]

I didn't even thing about making the lift hydraulic, I just thought I would make a long lever which was attached to the I-beam. But since I've got the pump and the power, why not!? Some more investment with another piston, but this is only going to be lifting ~500lbs + the weight of the apparatus, so that should be no problem. I'll have to make sure it doesn't launch it too fast... I don't want to THROW rounds like that around.

Awesome! You were right about finding a splitter I like. http://www.timberwolfcorp.com/tw-6-log-splitter-optional-equipment.html

Those options are what I want. I like how the 4-way (or 6!!) just slips over the 2-way post. The hydraulics for that is just icing on the cake. I would be OK with a bolt.

 

[Jags]

Take a look at the specs on the timberwolf. That will give you a guide for components.

 

[CombatChris]

Yea, I'm looking, and I see the price of one of theirs with all the options. http://www.alexequip.com/product/timberwolf-tw-6-log-splitter/

$11k? No thanks, this is going to be even better. I was comparing my cost to some of the cheapest ones around and it was going to be a wash. Vs this, huge savings.

Thanks a ton, Jags, for getting me pointed in the right direction and giving me some ideas. I think I've got this under control and now I need to start searching for good used parts to build this up.

 

[Jags]

No problem.

 

[brant2000]

Here's I guess the list I'm forming.


4-blade option - I would like to be able to remove the single blade and put up a 4-way wedge, if I can figure out a good way of engineering the swap system.

A coworker made this 4-way attachment for his. It just slides down over the existing wedge and is easy enough to take off. He also added a hydraulic lifter to it. Instead of going with a second control valve lever, he uses a selector switch. Just another thing to think about.