Help in Hydraulic circuit needed :(

[polemidis]

Hello, I am building a Firewood processor and the frame and mechanical staff are close to be done. I need a little help with the hydraulic circuit. In order to keep things simple for now, and to work with what I have in hand as much as possible, I removed the splitter circuit. It will run separate with its own gas engine and 2-stage pump.

So here is where I am with my homework firewood proceesr vbom - Google Slides
Its a google slide, feel free to duplicate the page and make edits if its easier for you.

Can you see any mistakes? Do I need something else? Is there anyway to improve the circuit or is there anything that will cause me trouble?
I studied the manifold of the 9kproducts with all the cartdridges, and I think its too advanced for me, and I do not even know how to make it, so I ended up with the above design.

Any insights plz?

I know there are some hydraulic gurus in here! And I do not have a hydr. shop closeby to me

P.S. I did study all the other related posts in TBNforums, which helped me to end up with that circuit.
I am also attaching the image if its more convenient for you guys.

EDIT: Also I was wondering where and how many pressure gauges should I install in order to troubleshout/tune the circuit.

 

[mikester]

Maybe I’m misunderstanding something but it doesn’t look like you have enough pump for your required flow circuits. You have a flow divider then nearly 100% of the pump flow taken on individual circuits

 

[oldnslo]

polemidis,
If I am reading your circuit correctly you will be feeding all of the valves via the CF port of the flow divider. This will only provide you 1/2 GPM flow not the 12 GPM. Very possible that I am reading it wrong though.

 

[polemidis]

Maybe I’m misunderstanding something but it doesn’t look like you have enough pump for your required flow circuits. You have a flow divider then nearly 100% of the pump flow taken on individual circuits

I noted under the flow divider text box how much fluid I estimate to divide. Can you explain a little more what you mean? Other than the saw motor and the "chainbar advance cylinder" no other functions will run at the same time.

 

[polemidis]

polemidis,
If I am reading your circuit correctly you will be feeding all of the valves via the CF port of the flow divider. This will only provide you 1/2 GPM flow not the 12 GPM. Very possible that I am reading it wrong though.

Sorry for the misunderstanding guys. I am correcting the term. Instead of "variable flow divider" I should wrote "Flow Control Valve". Its this valve. 12.5gpm got to the rest of the valves, 0.5gpm go to the outfeed conveyor. I added some links to avoid confusion

 

[farm boy00]

Sorry for the misunderstanding guys. I am correcting the term. Instead of "variable flow divider" I should wrote "Flow Control Valve". Its this valve. 12.5gpm got to the rest of the valves, 0.5gpm go to the outfeed conveyor. I added some links to avoid confusion

Why only 0.5 gpm for outfeed conveyer?

 

[polemidis]

Why only 0.5 gpm for outfeed conveyer?

If I am correct with my calculations that flow with the 4.45in³ motor, gives me 3ft/sec and 5x load capacity than it will ever have to convey. I think its enough. If not I can always tune it up!! I want the minimum so I can feed the hungry saw motor!
Btw I found some mistakes on the design, trying to figure them out. The main problem is the chainsaw motor/saw feed cylinder relation. Its a delicate one I cannot push too hard or the chain will stall, I cannot push too little or I will wasting cycle time. And the 12gpm on the 0.58inï½³ motor just gives me adequate torgue and chain speed. Its not that I have abundance of power.

So my update is that I am trying to simplify the 6kproducts manifold. I am convinced that a manifold is the way to go for the saw motor/saw feed cylinder. I get a quote from a company for a custom manifold they need $2000-$3000!!!! so its a no-no.
Attached is the 6kproducts manifold if someone can help me read it or I have to ask in a hydraulics dedicated forum:confused3:

 

[oldnslo]

Polemedis
Can you put together a detailed list of what you want the manifold to do? If yes then someone can probably provide some help.

What are your intentions on control style to control the saw feed rate? 6K system looks like electronic (proportional) pressure control system. Are you going to have some type of electronic controller on your machine?

The only input command source that I can think of is the saw motor pressure. Reason for this is pressure equals motor torque and that is what you are trying to limit is max torque of the motor. You would have to use the motor pressure as the command to control the feed rate. On 6K system this the proportional pressure control for down pressure. Another option is proportional flow control on the feed cylinder. Both require some form of electronic control.

Doing this via hydro mechanical you could possibly use the pressure signal of the saw motor to control a valve controlling the drop speed. This would require a pressure controlled valve with very precise metering. Not sure who makes that type of valve.

 

[polemidis]

Oldnslo, what I deeply trying to do is to Open Source a manifold for a firewood processor, so whoever wants to build one later, to have it ready and do not have to go through all that hassle I did. Thats why my CAD design is also open.
Now in particular, my main problem was on how to operate the feed saw cylinder. I was stuck on a relative easy thing though! The way I solved it (in paper at least) is to add the feed saw Directional valve under the Flow Control Valve that sends oil to the outfeed conveyor (check my diagram). That way I can still use at the same time and the saw motor and the feed saw cylinder.

Now, since I invested so much time on research, i am trying to figure a way to automate this process. I mean, using one Lever, 1st to Clamp the wood, then with a sequence valve to continue on the Saw Motor and and on the Feed Saw Cyl.

The 6k is not electronic. I analyzed the valves he has on his manifold, and I was able to copy most of them. In short he has a manifold that takes on the push of the directional valve it takes the oil in, TEE'S it and then redirects it to a) a flow control valve (Sun-FXDA) with no check set at 12gpm, which then sends to the Saw Motor and b) to a flow control valve with a check valve for free return (Sun-FCCB) of 0.5gpm that sends to the Feed Saw Cyl.
The saw motor oil is returned to the tank, while the return of the Feed Cylinder is coming back to the manifold, through a check valve (Hydraforce CV08-20)with a spring setting at 150psi, and then through the check valve port of another flow control valve (Sun-FCCB)
Now on the pull action of the directional valve the oil is pushed through a flow control valve (Sun-FCCB) setup at 1-2gpm.
This is what I analyzed from his picture, and I managed to make a manifold in Sun Website Design, which I have attached it.
They quoted me back that this block complete costs $440. Does it worth it? I do not know. Depends on the volume of firewood I guess. But its not much for the function it does on a Firewood Processor. Does it work? Still do not know, there is a chance that I did not read 6k picture right. Or even 6k published a inaccurate one! I do not know.

That being said, 6k, has also 2 more things incorporated, 1is which is a pressure modulating valve for the Feed Cylinder. But he does not mention which exactly cartridge he used. He mentions just a "3 port 3000psi modulating valve". I cannot understand how he plumb it exactly, since he utilized 2 ports out of the 3, and I do not know the cartridge I do not want to risk it, so I left it out. Hopefully its not important. I am planning to add a "manual pressure regulator !!" which is a spring after the cylinder rod end so it can absorb some pressure when the cut is through the center of the wood.
The 2nd thing is a simple "TEE" towards the bar oiler but I am not going that route personally.

The precise metering you mention is easily done with the orifice on the flow control valve. In our case, the FCCB valve can regulate the flow from 0.1 - 6gpm with replaceable orifices.

Where I need help?
a) Someone to confirm/suggest/point errors! Since I started that thread I found a MAJOR fault in the design. I also though that it would be nice to add conveyor,splitter,clamp pressure gauges. What else can be improved?
b) if someone can compare my design so far to 6k picture. I didnt use the Hydraforce cartridges, put some equivalent(??) Sun ones.(SUN-CXDA) (both resources are attached above)
c) someone to give more info on the 3post modulating valve and how to connect in my diagram. Or just a simple explanation on how it works, anything helps.

Or at least where to ask! Sun's distribution enginnering department quote me $2000-$3000 to design me a custom manifold!! I cannot afford or justify that money!

P.S. I will improve the design by adding the sequence valve into it. 6K design does not control the Clamp, you need another valve for that.

 

[oldnslo]

Polemidis,
I mis-understood what you were asking. I took your question or concern on how to prevent over loading and stalling the saw motor and yet keep it cutting at close to max capacity. I suspect that is the function of the "pressure modulating valve" which I believe has all three ports connected. The 6K manifold does show elevation or layers at which the drill passages run so semi difficult to say exactly what connects where.

Connections to the "pressure modulating valve"
Top port: Connects to the Saw motor & feed oil in port.
Middle port: Connects to the CV08 150 check valve
bottom port: Connects to saw out.

I also have no idea on who makes the pressure modulating valve.

I believe that you will find one of manifolds to be rather expensive unless you can find a company that specializes in low volume manifold design and fabrication. The reason for this is that you are paying for the design time, machine set-up time in just one piece Vs 100's of pieces.

If saw cutting time is not important you can just set the feed rate so that on the largest toughest wood the saw does not stall and on smaller pieces you just wait longer.

good luck.

 

[polemidis]

Polemidis,
Connections to the "pressure modulating valve"
Top port: Connects to the Saw motor & feed oil in port.
Middle port: Connects to the CV08 150 check valve
bottom port: Connects to saw out.

I also have no idea on who makes the pressure modulating valve.

I believe that you will find one of manifolds to be rather expensive unless you can find a company that specializes in low volume manifold design and fabrication. The reason for this is that you are paying for the design time, machine set-up time in just one piece Vs 100's of pieces.

If saw cutting time is not important you can just set the feed rate so that on the largest toughest wood the saw does not stall and on smaller pieces you just wait longer.

good luck.

Thank you The middle port looks like it connected to the port 2 (outlet) of the cv08 25 check valve and to the port 1 (inlet) of the cv08 150 check valve though. And the top port, I am not quite sure. I believe that it is blocked maybe? Anyway, I am not going to risk a manifold with this cartridge, i will leave it out, and lower the feed rate,I agree.
About the manifold, I learned how to use Sun hydraulics quick design and already submited it. I got a quote of $440 for the whole assembly. Manifold 5 cartridges and 5 ports. Not that expensive not too cheap. I guess if I want that automation I will have to pay. But look, an extra directional valve + a variable flow divider + a cast sequence valve + all the extra hoses to connect these parts will get close to that.

So, right now, I am redesigning the manifold, I will remove the check valves/ modulating valve, I will keep the 2 flow control valves (one for the saw motor at 12gpm and one for the feed at 1gpm, I will add the sequence valve inside the manifold, and also I will add 2 ports for pressure gauges. If it stays around that money I will go for it.

Thank you for your time!

 

[oldnslo]

Polemidis,
I sent you a pm

 

[polemidis]

This is the manifold design I came up with so far.

I has a sequence valve (SCCA) that waits the clamp cylinder to build some pressure, then tees to 2 flow restricting cartridges a)12gpm to the saw motor (FDXA), and b) 1gpm to the feed cylinder (FCCB), and then I have a modulating cartridge that senses pressure on the saw motor, which when triggered, it permits some oil to pass from the feed cylinder extension, to the back side. A check valve with 100psi cranking setting keeps some back pressure to the feed cylinder.
I just found a major fault though, as I was writing the explanation of this circuit!!!!!!!!!. The modulating valve also releases pressure on the clamp which is bad, I will try to relocate the return..
Other than this fault, what this valve suppose to do (hopefully) is to pulsate the chainsaw bar when the chainsaw speeds down. What we do when we operate the chainsaw. Hopefully that intelligence will work!

 

[oldnslo]

Pole,
A couple of questions on the circuit.
1) What are the connections to your directional control valve that is supplying oil to this manifold?
2) My concern is that I don't see how the clamp and saw feed can retract. I could be missing something on the circuit though.
3) You can only build 100 PSI in the retract circuit to pulse the saw feed will this be enough pressure?

may have more questions or concerns once I analyze this further.

 

[polemidis]

Pole,
A couple of questions on the circuit.
1) What are the connections to your directional control valve that is supplying oil to this manifold?
2) My concern is that I don't see how the clamp and saw feed can retract. I could be missing something on the circuit though.
3) You can only build 100 PSI in the retract circuit to pulse the saw feed will this be enough pressure?

may have more questions or concerns once I analyze this further.

Sorry, its a little confusing!
Here is the updated design, with the correct place for the Clamp retract (I think so at least!)

1)
"OIL-FEED" is connected to the Directional Control Port A
"OIL-RTRC" is connected to the Directional Control Valve port B
"CLAMP-EXT" is pushing the Clamp
"CLAMP-RTRC" is retracting the clamp
"FEED-EXT-CYL" is connected to the cylinder port that pushes the chainsaw bar into the wood
"FEED-RTR-CYL" is retracting the chainsaw bar
Anything with "GAU" is a pressure gauge

2) On the retract: When I push the directional valve port B, oil goes to the "OIL-RTRC", through the "12-FCCB" flow control valve (Do i really need this??? maybe I will remove it), continues to the "TEE" then we have 2 flows"
a) The first flow retracts the Clamp through the "CLAMP-RTRC" port. On the return, low pressure oil from the "Clamp-Ext" exits towards the "Oil-Feed", back to the Directional Valve, and back to the tank.
b) The second flow after the TEE, goes straight up through the "8-CXBA-30" check valve (30psi to crank it open, thats why the clamp retracts first), continues up and left to the "FEED-RTRC-CYL". On the low pressure, return oil enters the "FEED-EXT-CYL, goes up through the check path of the "11-FCCB" then through the check path of the SCCA(sequence valve), and back to the directional valve and to the tank. It may run the saw motor a bit? I do not know, maybe, I do not think its a problem anyways.

3) It concerns me too. The 6K had 150psi. The CXBA check valve max cranking open pressure is 100psi. Sun, has another check valve with higher flow that can be adjusted for 150psi. If you think 100psi is too low, then I will upgrade. Do you think that 100psi will open the check valve too easy, result too much pulsation??

 

[polemidis]

Latest news guys is a sad realization that Sun's distributor in MA wants $1200 for this assembly (cost goes to $400 for 20pcs!). So that is a dead end, I do not think anyone can justify that much money. Here is the final design that I believe will work. Once again a lot of thanks to the guys who helped me! My new approach is to go with regular stock manifolds. I will need 4-5 of them, but I estimate the cost will fall below $250!! I already purchased 3 of the cartridges valves for $30each on ebay I will get back to you when I actually test the circuit in action.