adding hydraulics advice

[SawyerTed]

Portable or stationary?

For a portable hydraulic setup, sawhead engine powered, a pony engine or battery powered electric are the practical choices.  A generator driven 120v or 240v hydraulic system is not as clean a portable solution but has the advantage of being plugged in at a stationary location. 

For a stationary setup electric is hands down the best option.  Even three phase hydraulic power packs aren't the obstacle they once were with digital phase converters commonly available.  The auction sites have electric hydraulic power units frequently.  Maintenance is lower on an electric hydraulic unit and costs less to operate. 

[fluidpowerpro]

Yes, a valve like that should work. I ordered a valve like that when I was building my mill and even though it said it came with SAE ports, it had metric ports. The port adapters would have cost 3x more than the valve so I returned it. I ended up buying from Summit Hydraulics in AZ. They bring in these offshore valves also, but you can be sure the ports are what they say they are. They also offer a power beyond plug for theirs. If you ever want to add another valve downstream, you will need one.

[Georgia088]

Yes, a valve like that should work. I ordered a valve like that when I was building my mill and even though it said it came with SAE ports, it had metric ports. The port adapters would have cost 3x more than the valve so I returned it. I ended up buying from Summit Hydraulics in AZ. They bring in these offshore valves also, but you can be sure the ports are what they say they are. They also offer a power beyond plug for theirs. If you ever want to add another valve downstream, you will need one.

Thanks!  What about the hydraulic cylinders I linked.  Do those appear to be correct?
Thanks!

[D6c]

Also, as I begin to gather up parts for this, I am looking at the control valves.  I know that I need the standard open center valves, but I don't see any at the surplus center for a decent price, unless I am looking at the wrong thing.  I can find what appear to work on amazon for a reasonable price. Yes, I know it may not be the highest quality, but I can go through a few of them before I get to the price that I see on surplus center.  This is what I am looking at on amazon.  

Amazon.com: GYZJ Hydraulic Flow Control Valve 4 Spool 11 GPM SAE Ports Adjustable Relief Lever Handle Double Acting Parallel Center Tractor Loader W/ Joystick Small Tractors/Tanks Loaders Log Splitters 3600 PSI : Everything Else

Any input on if these (cylinders above as well) will work for this project?

Thanks!

I think to these are what I used on my mill.
9 Spool Prince SV Sectional Control Valve Open Center | Prince SV Complete Valves | Prince Model SV | Sectional Control Valves | Hydraulic Valves | Hydraulics | www.surpluscenter.com
You can build your own stack for the number of circuits you need.  Prices may have jumped since I bought mine.

[Don P]

Hopefully you won't mind if I tag on to that to see how this works from the experts.
If you had a 12volt pump with say 1.5 GPM. 

1.5 gallons/minute x 231 cu inches/gallon=346 cu in/min .. 346/60=5.76 cu in/second

A 2" dia cylinder 14" long - 3.14 x 1² x 14 = 44 cu in

44 cu in / 5.76 cu in/sec= 7.6 second stroke time

It'll output triple (3.14 x 1²⁾ the input relief pressure as rod force.

Is it that simple?

I think it does look like it would take 2-3 batteries to run a pump of that size at full work, that's a lot of charging.

[Southside]

To paraphrase what Don said.  The pump on my 35 is a 12V and I think in the 2.3 GPM range.  It is effective, but it is slow when it comes to turning a big log.  

[Georgia088]

Also, as I begin to gather up parts for this, I am looking at the control valves.  I know that I need the standard open center valves, but I don't see any at the surplus center for a decent price, unless I am looking at the wrong thing.  I can find what appear to work on amazon for a reasonable price. Yes, I know it may not be the highest quality, but I can go through a few of them before I get to the price that I see on surplus center.  This is what I am looking at on amazon.  

Amazon.com: GYZJ Hydraulic Flow Control Valve 4 Spool 11 GPM SAE Ports Adjustable Relief Lever Handle Double Acting Parallel Center Tractor Loader W/ Joystick Small Tractors/Tanks Loaders Log Splitters 3600 PSI : Everything Else

Any input on if these (cylinders above as well) will work for this project?

Thanks!

I think to these are what I used on my mill.
9 Spool Prince SV Sectional Control Valve Open Center | Prince SV Complete Valves | Prince Model SV | Sectional Control Valves | Hydraulic Valves | Hydraulics | [url=http://www.surpluscenter.com]Surplus Center[/url]
You can build your own stack for the number of circuits you need.  Prices may have jumped since I bought mine.

Thanks! I think these are the ones I looked at, but it would be almost quadruple the amount if I stacked 2 valves from here as the 4 valve set I linked from Amazon. I was just shocked at the large difference in price! I was just wondering if I was looking at the wrong thing. 

Hopefully you won't mind if I tag on to that to see how this works from the experts.
If you had a 12volt pump with say 1.5 GPM.

1.5 gallons/minute x 231 cu inches/gallon=346 cu in/min .. 346/60=5.76 cu in/second

A 2" dia cylinder 14" long - 3.14 x 1² x 14 = 44 cu in

44 cu in / 5.76 cu in/sec= 7.6 second stroke time

It'll output triple (3.14 x 1²⁾ the input relief pressure as rod force.

Is it that simple?

I think it does look like it would take 2-3 batteries to run a pump of that size at full work, that's a lot of charging.

You lost me a bit with the math. I am trying to understand it, but apparently my little pee brain isn't capable. Are you comparing a 2" diameter cylinder vs a 1"? Or, a 12" stroke vs 14? Or, am I missing the point all together? 
Thanks all!

[Don P]

I was figuring out the fill rate of a 2" dia x 14" long cylinder with a 1.5 GPM pump. Will a little pump keep up was my question. I suspect a power steering pump would work but you would be too old for the second board.

The volume of a cylinder is pi x radius squared x height. The radius of a 2" circle is 1" so that is where the 1² came from. ..

Volume= The area of the piston times the length of the tube.

Output force at the end of the rod is pi x r² x relief pressure.

Force= The area of the piston times the pressure.

and I think a single battery can handle about a 1kw draw for a short while. From a quick look, at full load it looks like these 12v pumps can draw 3kw. I believe that would take 3 batteries in parallel for a sustained draw in that range. But rarely will you have that draw, I think. They can handle seconds of heavy draw. Either way I think you need a healthy charging system if the hydraulics work much.

Doug made a comment about not needing all that much pressure. I'd bet you can find a higher flow/lower pressure/ lower kw draw combination that fits "best" for the situation.

This is all a ramble hoping for understanding from them that knows more than me, not gospel!

Now I better sit on my hands  

[fluidpowerpro]

A formula I always used throughout my career to figure cylinder speed was:

Area X Length X .26 / GPM = Time  (in seconds)

You can also swap time for GPM and get GPM required.

Area X Length X .26 / Time = GPM required.

I liked this one because its easy to remember....

[fluidpowerpro]

Doug made a comment about not needing all that much pressure. I'd bet you can find a higher flow/lower pressure/ lower kw draw combination that fits "best" for the situation.

Unfortunately "work" is "work" so whether you accomplish it with high flow and low pressure, or low flow and high pressure, the input HP (kw) will be the same.
High pressure and lower flow does have some advantages as far as line sizing. By designing to run at higher pressures, your flow requirements will be less, so your line sizes can be smaller.