wood processor hydraulic circuits

[muddstopper]

Ok, I will admit, I am not the best hydraulic engineer. I have just enough sense to ask for advise. I just need opinions and suggestions on my proposed hydraulic setup. I was going to try and draw it out in Autocad, but the software I downloaded is buggy and wont display the symbols correctly. Anyways, here is what I have in mind.

First off, saw motor is a 1.3 cuin Proclain axial piston motor, and splitter cylinders are twin 4.5X2.5X30in stroke. Engine 190hp diesel. I have 2 sets of stacked vavles, 10 spool and 8 spools, all spools have own reliefs. Rated for 25gpm. I have a v70 parker, spring centered, lever and air actuated. Plan on using foot pedal to operate. Looking for single spool valve with PB for saw motor. Must be rated for at least 30gpm.

I have been writing my thoughts down so this is just a copy and paste of me talking to myself. Sometimes I even answer myself, and sometimes the answer is even correct. Oh well


Processor Circuits/Functions

Current plans are for 3 separate pumps I am labeling these pumps as P1,P2, and P3. If i decide to add another pump, it will be considered P4.

Saw motor 33gpm flow P2 pump
Splitter cyl 42gpm flow P1 pump
P1 and P2 pumps will combine to provide 75gpm for splitting cylinders

14gpm, P3 pump
This pump will provide flow for all other circuits

Saw cyl
log clamp cyl
Log feed conveyor motor
wedge lift cyl
Out feed conveyor motor
Live deck motor
Deck lift cyl

Knuckle Boom Circuits/Functions
Since all previous listed functions will not be required while operating Knuckle boom, the P3 pump will be used to supply power
Right stabilizer cyl
Left stabilizer cyl
Mast rotation Motor
Root boom cyl
Dipper boom cyl
Grapple rotator motor (Valby R3)
Grapple clamp cyl

There is the possibility that I might make the outfeed conveyor to fold up for transport as well as swing side to side. For fold up, Scropion style, I think it would take two extra cylinders. One to raise the conveyor and the other to make it fold. I am thinking one control valve and using sequence valves so that the conveyor folds first and then raises and then lowers before it unfolds. Have to think about this, it might just be easier to use to seperate CV's. I guess it just depends on how may extra spools I have in my stacked valves. One cyl, one CV,extra if I decide to add swing.

Also, Not entirely sure I will use or need a fold up log deck for log storage, I should have about 4 ft of live deck and the knuckle boom will be mounted to the machine, so???, is the extra lenght of the live deck worth the trouble.

Advantage of a longer deck is you can load a bunch of logs for processing so you dont have to stop and reload logs as often.
Disadvantage, Cost more to build, and in the folded position it would be upright making machine height higher . Would also take up space needed for knuckle boom storage during transport.

I think the best way to figure out what valves I need is to just do them one function at a time. Since the saw and splitting circuit will use a combination of two differnt pumps, I will start there. After I write this out, I will try and draw up the schematics using proper symbols. Autocad software buggy, so this might take a while.

Starting with the saw, P2 pump makes 33gpm. flow will go to valve with relief between valve and pump. (Relief Internal in CV). SCV activated fluid goes from SCV to Motor and then to Tank. Valve in center postion, flow will go to PB and continue to CKV before combining with P1 pump flow. CKV is to prevent P1 pump flow from running backwards to saw motor.

Considering also adding a unloading valve with check valve bypass in the event P1 pressure rises above P2 pump relief setting which would cause P2 pump to dump over relief instead of going thru splitter valve. A unloading valve would allow oil to flow back to tank unrestricted instead of flowing thru relief valve. This would also make the P2 pump act as a high/low pump. Making the splitter act like it had a two stage pump instead of 2 seperate pumps.

P1 pump flow combines with P2 flow at tee and then to the in port of Splitter control valve with internal relief. Splitter control Valve In center position flows to tank. When activated it would extend or retract twin splitting cylinders. The twin cylinders are connected together in parallel.

I think this completes the splitter and saw circuits. All other circuits will be using the 14gpm P3 pump.

To complete the sawing of a log, I need to address the conveyor to advance the log as well as the clamping and lowering of the saw bar. Since this operation would be thru stacked valve, It should be as simple as activating the corresponding control lever and push and pull. Not so fast!! While this will work just fine for the conveyor. I am going to be dealing with different flow requirements as well as pressure requirements for the log clamp and saw cyl. Saw cyl needs to raise and lower in a controlled manner and pressures also need to be pretty low.

Recommended down force on saw cyl is less that 100psi pressure at mid saw bar. (Oregon recommends 60lbs force at mid bar).Log clamp pressure can be system pressure. I am thinking this is going to require more valves to make it work. My Ideal is to use a sequence valve off the log clamp cyl to activate the saw cyl. This way the clamp would see a set pressure to hold log in place, before the saw cyl moves. Still ,I dont think this will work because the saw cyl would also see full flow and pressure making it to fast and apply to much force. I can use a couple of flow controls to meter in and meter out flow to control speed, but then I still have to much pressure. To control pressure what about using a pressure reducing valve before the flow control valves. Thats a lot of plumbing for one cyl. Got to be a better way.

Advantage of using seperate flow control, sequence valve and pressure reducing valve. It allows wide range of adjustments to control both speed and force.
Disadvantage, Lots of valves and hoses to buy $$$, and very cluttered once installed. will have to see if possible to buy a all in one valve to perform all these functions. All in one valve will probably be cheaper than buying several seperate valves.

Next operation is where I might have to add an additional pump (P4) and that is the out feed conveyor. Conveyor needs to run continuous while sawing and splitting. If I pull fluid off the same pump as I am using to run the other conveyor as well as the log clamp and saw cyl, the outfeed conveyor will see start and stops. The outfeed conveyor and other splitting functions wont be running if I am running the knuckle boom. I have a few choices to make the out feed run all the time, I can add a divider valve before the clamp, sawbar and log feed and just dedicate a set amount of oil for that conveyor. I can add another small pump or I can pull some fluid off the splitter circuit as that valve is also PB. Not sure how I would get flows down to 4-5gpm from a 75gpm circuit, but I bet it would be costly.

Not a lot to discuss about the knuckle boom, except for adding a brake valve to the mast swing motor. While I could probably get by without the brake valve, I dont want the mast to be floating around uncontrolled if the machine isnt perfectly level.

I know I am crazy, but give me your suggestions and thoughts on making this system work.

 

[/pine]

This sounds like an awesome machine when completed...
Not to detract from your thread...!
What I'm most interested in is the knuckle boom...I'm planning on building a much smaller, less complex processing system...but a knuckle boom is a priority...
Are you fabricating all the assemblies from new material ?
I'm building a mobile system (currently using tractor hydraulics) but I want to make my knuckle boom as both a 3PH attachment and have it mountable to the splitter/processor rig...
Do you have working plans for your knuckle boom?

I hope to start work on my own k_b_...in Jan. so I have not done much searching/researching etc...

Looking forward to reading about your progress on your processor.

 

[muddstopper]

Pine, here is the thread discussing my knuckle boom plans. http://www.tractorbynet.com/forums/build-yourself/323206-any-body-built-knuckleboom-loader.html. I dont have it built yet. I injured my arm back in March and have had to put a few things on hold. I have parts for the loader, as well as the processor laying stacked up everywhere. I did buy a Valby rotator for $800 free shipping. Since I do plan on mounting the loader on the processor frame, I cant really put it together until the processor is build. Sort of have to build them at the same time.
As for using new Materials, couldnt afford it if I was. I have been gathering parts for several years to do this build. Some things, Like the Valby rotator, I had to buy new. I looked for a used one for a long time. Kept thinking sooner or later I would run across one. Didnt happen. The biggest majority of the metal is used, I did splurge for a stick of 5x5x1/4 sq tube to make the boom. I also had to buy the large 72 tooth sprocket, about $100 off ebay, to turn the mast with. Just the parts I listed is around $1100. I had some machine work done that also cost $500 and the truck axle cost me another $100, Couple cyl another $100, so I am into the loader about $2 grand and it is still setting in the floor waiting to be put together. I have managed to find the control valves for nothing. Not really sure I am saving any money building the loader versus buying one used. If you have to buy all new materials, I would just look for a used loader, probably be cheaper, even if it needs some repairs.

 

[muddstopper]

I have two different Husco stacked valve bodies. Both 5000 series, 5005a. One valve came off a ditchwitch and is currently on my wood splitter, it has 6 spools and I am only using one of those spools for the wedge lift. Long story but anyways. The other valve is a new 10 spool I salvaged from a scrap bin. Both valves have PB. The 10spool valve also has the center combiner valve section for adding more flow to the valve, Not sure how its supposed to work, but I dont need it so it will be taken out of the circuit. . The 6 spool valve has a main relief and three spools have additional reliefs. . What I want to do is take one section out of the 10spool valve and add it to the 6 spool valve. I also want to remove the combiner section completely and reduce the number of spools to just 5. If i can find a couple of endcaps for a 5000series husco valve, I would be able to put together another set of 4 spools stacked valve. The reason for wanting to make put together the 4spool valve set is so I can put that valve back on my splitter. I need the seven spool set to operate my home made knuckle boom and the other 5 valve set is to operate some of the functions on my processor. Yea, i could just put the 10 spool valve on the knuckle boom and use the 6spool on the processor and have exra valves for each bu then I would have to find another valve with pb to put on my splitter. So if anybody has a set of endcaps for a 5000series husco valve set. Let me know

 

[seth350]

Wow thats quite an undertaking! Sounds like you have most of it figured out.

I am kind of having trouble trying to visualize everything, but what are you trying to accomplish with the joining of two pumps to the splitter cylinders?

Obviously, one good reason would be faster cycle times, but you can make the cylinders faster by "regenerating" the exhausted oil on the rod side back to the cap side. That is if you are wanting to extend them quickly, the caveat is this method does not work for retracting and has less tonnage. So a valve will need to be put in place to create a path for that exhausted oil to return to the piston side of the cylinder.

The "Combiner" valve you spoke of is probably a valve put in place so that you could engage that valve along with the extend valve for faster extension.

One thing you might want to think of is to combine P1 and P2 into one bigger pump, and then have a smaller pump for auxiliary motions. That would eliminate some of the "oil joining" you have and simplify the circuit more.

Or keep the P1 and P2 separate, but what happens to your saw blade speed when P1 and P2 combine to shove the splitters? If you have time for saw blade to get back up to speed before the next cut then I wouldn't worry about it. If you are cutting in succession along with splitting at the same time then I could see where you might run into problems. Depends alot on how big of a blade we are talking about and how fast you want it to turn.

 

[muddstopper]

P1 and P2 will go to separate control valves. The flows will only combine after going thru the saw valve using the power beyond port. With this method, i should have 42gpm available to the splitter cylinder's, ( there are two of these), at all times. The saw will also have its full 33gpm at all times, but when i am not sawing, That oil will go to the splitting cyl thru the in port of the control valve, that way when neither function is operating, all oil can return to tank. Now the cavet in doing things this way is the oil from the saw valve doesnt have a return to tank if the splitter pressure gets higher than the relief on the saw valve. To solve this problem, i think a unloader valve will be my best option. I can set the unloader valve a little lower than the splitter pressure. Then when the splitter pressure gets to maximum, the saw oil will just dump to tank. I might just go ahead and not combine the two oil flows. I am beginning to think that 6 sec cycle time with a 50ton splitter might not be the best ideal. Just supplying a extra tank port for the saw oil will be a lot cheaper than buying check valves and unloader valves. The splitting and sawing are the only functions these two pumps will be doing. Just to many other valves and combinations to buy to try and and change oil flows and pressure from 33gpm or 42 gpm to lower pressure requirements and oil flows. All other functions will be powered off a third 14gpm pump.

 

[seth350]

I agree with you on not combining the flows and I think you will pat yourself On the back later for it. It really simplifies the circuit and makes for simpler repairs.
You could incorporate some shuttle valves for diverting some of the flow elsewhere and still keep it simple.
Is your splitter horizontal or vertical? If horizontal, does it split going up or down?

 

[muddstopper]

splitter is horizonal. There are two 4 1/2in bore cyl stacked above each other.. Here they are, but not welded in yet. They will be pushing the wood thru a 12 way adjustable wedge. If I just use the 42gpm alone it will give me a cycle time of around 11sec. Combining the 33gpm with the 45gpm will give a cycle time of about 6sec. 6sec is extremely fast for any splitter, put 50 tons of pushing force behind it and a 12 way split and I am not sure how the pieces will fly off the end of the wedge. I am already imaging splits flying off the end. For that reason, I think I am jus going to keep the oil flows seperate for now. If i decide later on I need more speed at the splitter, I'll try and come up with a way to add more oil. Combine the flows is pretty simple, just need a check valve and tee. Regulating the pressure between the two pumps is the hard part. Relief valves are not exactly equal, even with the best of fine tuning.

 

[seth350]

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.

 

[seth350]

Just a though, not sure if your budget allows choosing a different pump...

A variable displacement pump with pressure compensated controls would allow you to smoothly split at a given force.
You would set the compensator to Xpsi, the pump would deliver max flow up to Xpsi. Once Xpsi is reached, the compensator reduces pump output so that Xpsi is maintained. It is essentially its own relief, but would also require a relief valve downstream in order to set the compensator resistance.

Resistance....a resistance operator could also be used to switch from high speed low tonnage to low speed high tonnage. It would allow the cylinders to quickly extend out in regeneration until resistance is equal to operator setting, then switch to high tonnange. This will make your cycle times more efficient as it could handle different lengths and always get to the log quickly and then split in high tonnage.
Fast out, hit the log, then smoothly split at a lower speed.

The resistance operator could be integrated with what you currently have, or get a pressure compensated pump to do the same thing.