wood processor hydraulic circuits

[Leejohn]

By looking at your picture, you might want to start looking for new H beam. It looks small.

 

[muddstopper]

Lookin hefty :thumbsup:

When you calculate your cycle time, are you saying a cycle is the time to split or the time to split and then retract?

When I calculated it with 4.5" bore with 2.5" rod at 30" stroke @ 42gpm, extension is 3 seconds and retract is 2 seconds. That is only figuring one cylinder. You have two cylinders dividing the flow, so you are actually looking at a 12 second extension and a 8 second retract. Because you are doubling the area, ending up with a 20 second cycle time total. Combine the 42gpm and 33gpm for 75gpm will give you a 6.5 second extension and 4.5 second retract. Total 11 second cycle.

For 50ton, you will need 1500psi capacity.

Seth, one of us is doing the math wrong. Two 4.5x2.5x30in stroke cyl should be equal to One 6.75x3.75x30inch stroke cyl. 3000psi would give me about 107,000 of splitting force, right at 53.5 tons.. Cycle time with 42gpm flow would be 11.3 sec. Extend @6.7 sec and retract at 4.6sec. One cyl @42gpm & 1500 psi would give me just under 12 tons and would cycle @ 4.9 sec. 2.9 sec extend and 2 sec retract.

I have considered your ideal about the variable displacement pumps. Since I am building on a very tight budget, with mostly hand me down and used parts, I have to use what I have scrounged. The 33/42 gpm pump (used), is available to me with little cost. Buying a Variable displacement pump is sort of out of the budget for right now. Not to mention all the valves to go with it.

 

[muddstopper]

By looking at your picture, you might want to start looking for new H beam. It looks small.

The hbeam is a 8x8x1/2 web and flange. I will be boxing inside the flange to give the hbeam a III look. I will also be plating the top of the beam to provide flange support. While the boxed wedge will be attached to the bottom end of the beam, it will also be braced both sides in the middle and the top. Bottom and top braceing will be about 30 or so inches apart. and the middle brace somewhere inbetween. Now, whether or not this will be enough remains to be seen. I bought a old forklift mast I will be making the slide box for the adjustable wedge. right now my biggest worry is turning the heavy walled channel inside out while under pressure. i will have to keep a sharp eye on it for certain.

 

[seth350]

Ok, I have looked at this the wrong way. I calculated both cylinders as being 9"x5"x30". 4.5x2 and 2.5x5. Which is wrong, you can't get a 9" piston from two 4.5".

So rather than doing it that way, let me do it the way that matters by looking at the area.

A 4.5" bore cylinder has 15.9 sq.in of area on the bore side, with 2.5" rod gives me 11 sq.in of area on the rod side.
A=3.14x(4.5/2)^2
A=3.14x2.25^2
A=3.14x5.0625
A=15.89625 sq.in

If I double that area for each side, which would indicate two cylinders of equal size...
Bore: 15.9x2=31.8sq.in
Rod: 11x2=22sq.in
So this area is what the pressure will be acting against.
#F=AP

Bore
#F=31.8x3000
#F=95,400
95,400/2000=47.7tons

Rod
#F=22x3000
#F=66,000
66,000/2000=33tons

Extend Speed
in.sec=(231 X GPM) / (60 X Net Cylinder Area)
in.sec=(231x42)/(60x31.8)
in.sec=9702/1908
in.sec=5.08
30" stroke/5.08=5.90 seconds to fully extend

Retract Speed
in.sec=7.35
30" stroke/7.35=4.08 seconds to fully retract

This looks better, and with it taking 6 seconds to extend and possibly a little longer if splitting large log, I dont think you will need to worry about splits flying everywhere. lol

 

[muddstopper]

I can do the math, but it makes my head hurt. I usually just use a online calculator. Your Numbers are close enough we dont need to be splitting hairs. Your other numbers on the other hand had me worried.

 

[seth350]

I totally understand, we can split hairs when we build a space ship. All that matters is it will split wood! :drink:
Yeah I was in left field with my other numbers, my mistake.
Not that I am trying to be too technical, and I might be so forgive me, I was just double checking your numbers to be sure you were right and weren't going to have an Uh-Oh moment down the road. I also enjoy the math and the physics.

For a po-boy wood splitter, your going to have a very capable one! :thumbsup:
Should be able to split anything you throw in it.

 

[muddstopper]

Of course the goal is to split everything that will go thru it. For something that started out as a add on to my current splitter. Opportunity just kind of threw itself at me. A couple of realizations I had with this build. One, you can build a big processor for about the same price you can build a small processor. Second, things only get expensive if you get in a hurry. I have been gathering parts for several years now. I bought a isuzu pickup with a diesel engine to run this thing about 3 years ago. Adding pumps and flows sort of out greww the little diesel pretty quick. I paid $300 to get that engine. I have a buyer coming to pick it up in about 2 more hours. Going to actually make a profit and beginning to think I priced it to cheap. I have had folks from as far away as N Dakota, New York, 3 from Tenn, Florida, and the guy coming to pick it up is driving from Thomaston Ga.

Anyways, I have been studying how to build this thing for a while. All the studying has given me a little ideal as toward what parts to look for. Some things I know I just aint going to find around here. Knowing what to look for and not being in a hurry pays dividends. I have some very high priced parts I have been able to get for free or next to nothing. My goal is to have this thing working for less than $10 grand. I am well below that figure right now. Hydraulic hose will be my next major expense. Doubt I can find good ones or right lengths at the bone yard.

Here is just a sketch for my hydraulic layout. Just trying to decide how I want the controls.View attachment valve drawing.pdf.

 

[seth350]

You are right, fast means cash. You have done extremely well getting these parts for that budget.
I tried opening your sketch but didn't work. I saw you said your autocad wasn't working. If you need it in autocad I can take a sketch and draw it up for you. I have hydraulic components with autocad electrical 2014.

Just shoot me an email seth350 at gmail dot com

 

[rswyan]

By looking at your picture, you might want to start looking for new H beam. It looks small.

Yupper ...

I'm running a 4" cylinder @ 2200 max psi (almost 14 tons of force) on an 8 x 6 1/2 W24 or W28 H-beam ... and ends are boxed in for about 6 1/2" with drop pieces of the flange (3/8"+ thick). The cylinder mount and splitting wedge were both attached by cutting thru the flanges and web of the beam and running 1" thick plate down thru both, and welding it all in. Additionally, the top flange is reinforced (plated) with a second piece of flange at the cylinder attachment point:

Logsplitter 2.0

You can easily see the beam bow when the splitter encounters something it can't split - the deflection is significant. Kinda freaked me out the first time I noticed it.

 

[muddstopper]

Seth, The file is a pdf file. It opens for me. My auto cad is 2015 mechanical student version. I downloaded the hydraulic add on and the add on is whats not working. Some of the stuff will open and some of it wont. At any rate, I think for you to draw it in auto cad, you would need more than what I posted in my drawing. I do appreciate the offer and might just take you up on it. I will be going out of town today. When I get back home, I will try to make a more detailed description and send it to you and then you can decide if you want to attempt to draw it in CAD.