Yet Another FEL Snowplow Angle Hydraulics Question

[quadridermx]

Long time lurker, first time poster here! I have spent hours and hours reading on here before my first tractor purchase. So much knowledge. Was hoping to get some clarification on this age-old topic. I've read a lot about it through the search function, but still have some questions about the details of hooking up the hydraulic angle cylinders correctly.

My rig: New to me 2000 Kubota L2500 2WD. Has a Rhino FEL on it. I have taken the bucket off the front end loader and made some brackets to fit a 6.5ft Curtis plow I just acquired. While doing some research, I believe I actually found the original owner's post when HE mounted it to HIS Kubota 10 years ago on this site! http://www.tractorbynet.com/forums/...33702-kubota-curtis-plow-mount-hydraulic.html It is the exact plow that ronjhall shows, a few posts down in that thread.

Currently I have the arms mounted into the bottom mounts on the rig and of course the bucket curl cylinders mounted into the top mounts. It works great for lifting up/down and "curling" the angle of the plow.

The plow has two single-acting angle cylinders to angle the plow left/right that I want to hook up. I am in hydraulics kindergarten, but eager to learn as much as I can. I understand the basic concepts of hydraulics, but have several questions. I really appreciate any help! Monetarily, I need to do this the cheapest way possible to still be strong and effective, but this is only for my home driveway so I only need something basic. I would like to use the current FEL valve block/lever if possible. The FEL valve I have is loader arm up/down and then "float" if pushed all the way forward. Then there's bucket curl up/down with quick dump if pushed all the way to the right.

Questions:
1) I assume the cheapest way to get the hydraulic angle working is to buy a manual selector valve that cuts off flow from the curl cylinders, locks them in place (not allowing fluid to freely flow back into the hydraulic tank), and diverts flow to the two single-acting angle cylinders of the plow. In theory, I would set the plow "curl" angle, change the selector valve over, and then have control over plow left/right angle.

I have read that this is the cheapest, most basic way to accomplish this. My question is.... Can someone please tell me what selector valve I would need? Maybe an example from surpluscenter?

2) I am getting confused when it comes to the need to "lock" pressure in the lines, as opposed to letting pressure out. For example, I assume that for the curl function, I need a selector valve that will "lock" the pressure in the loader curl cylinders. That way when I switch the valve over to it's second position to control the angle cylinders I won't lose the curl angle of the plow. But in the second position of the selector valve, it seems I would need it to allow "return flow" from the angle cylinder that is being compressed so that the two cylinders don't just fill with fluid and become hydrolocked against each other.

Am I correct in my thinking? Or would the loader joystick block take care of all that?

3) If you can point me in the right direction as to what selector valve block I would need.... where would I mount it? Since I would be diverting the fluid flow from the curl cylinders, would I need a selector valve that accepts the two curl outputs from the loader joystick block, or would just one do?


Please help! I am at the point where I can quickly understand hydraulic design when it's presented to me, but can't quite figure out the design on my own. Thanks so much anyone that can clear up this muddy mess in my newbie hydraulic brain!

 

[J_J]

You can use the curl cyl hyd to operate two SA cyl as long as you do not use regen.

If you have regen in the first part of the lever movement, just push the lever to the far right.

If you have a remote valve, you can use it to control the SA cyl. A/B work port, same spool.

 

[quadridermx]

Thanks for the reply. I have regen, but it is to the far right, so I should be good there. I don't have a remote. Only the supply line going to the loader joystick, and return going back to the sump.

Can I plumb in a 2-in 4-out manual selector valve like this one?1/2" NPT 20 GPM DOUBLE SELECTOR VALVE

Run the two curl lines from the loader joystick valve into the input of the above selector valve. Then run 2 of the 4 outputs to the curl cylinders, and 1 output to each of the angle cylinders?

 

[Fallon]

If you have power dump & regen dump you can use a diverter on your existing dump valve & circuit.

Regen puts full hydraulic pressure to both the rod end & cylinder end of a cylinder. The larger surface area means the cylinder end will overpower the rod end. The extra fluid from the rod end fills the cylinder end. You loose a lot power this way but gain speed... Not a problem when gravity wants to dump your bucket for you.

If you apply regen to a pair of single acting cylinders both get full pressure & cancel each other out. No harm, but no movement either. So as long as you can get to power dump it doesn't matter if you have regen. If you only have regen sum as some do, no single acting cylinders for you without a new spool.

Normal spools (not motor spools) will close both ports when not activated. A diverter valve will be closed when not activated as well. Things won't move unless activated.

 

[quadridermx]

Thanks for the explanation of how the regen works. I have wondered that. Fortunately my loader has power dump AND regen positions, so I should be OK there.

So would this diverter work in theory?1/2" NPT 20 GPM DOUBLE SELECTOR VALVE

I would disconnect the two curl hoses from the loader valve. I would take two small hoses from the curl ports on the loader valve to the input of the diverter valve. Two out puts from the diverter valve would go to the two curl cylinder circuits (curl up/curl down). One of the remaiming two outputs would go to the plow left angle cylinder and the remaining output would go to the plow right angle cylinder.

Am I solid in my thinking with that? That way, when the diverter valve is in position A, I am operating the curl up/down as normal with the loader joystick. If I set the diverter valve to position B, I can now operate the plow angle cylinders with the joystick loader as well.

And from what you guys are saying, I don't have to worry about the curl getting any flow (ie moving) when I'm angling the plow in position B, because the A ports will be blocked off internally in the diverter valve. And vice versa. .

 

[Fallon]

Not sure on the valve. If it has detents to hold it in either position, probably.

Your other logic & plans sounds right.

 

[J_J]

If you have power dump & regen dump you can use a diverter on your existing dump valve & circuit.

Regen puts full hydraulic pressure to both the rod end & cylinder end of a cylinder. The larger surface area means the cylinder end will overpower the rod end. The extra fluid from the rod end fills the cylinder end. You loose a lot power this way but gain speed... Not a problem when gravity wants to dump your bucket for you.

If you apply regen to a pair of single acting cylinders both get full pressure & cancel each other out. No harm, but no movement either. So as long as you can get to power dump it doesn't matter if you have regen. If you only have regen sum as some do, no single acting cylinders for you without a new spool.

Normal spools (not motor spools) will close both ports when not activated. A diverter valve will be closed when not activated as well. Things won't move unless activated.

The primary reason for not using regen with SA cyl is that in a SA cyl, you have fluid on one side of the piston.

Using two SA cyl will work as the fluid from the non powered cyl is forced out through the same work port as the IN flow.

Using a SA cyl, non -regen, the fluid going into one cyl will force the fluid from the other cyl by mechanical action, and that will work.

If using regen with an SA cyl, The mechanical action of the snowplow can not force the other cyl to move as there is no place for the fluid to go as one work port is blocked and locked.

As you know some tractor valves have full time regen, no powered dump to the right.

 

[quadridermx]

Just an update to this... Everything is working great! Thank you for all your help.

For future readers of the thread, here's what I did:

1) Bought this 6-way (2 inputs, 4 outputs) selector valve: 1/2" NPT 20 GPM DOUBLE SELECTOR VALVE
This selector valve basically takes the 2 inputs and passes them straight through to two outputs at a time. You have 2 sets of 2 outputs. It does block off, or "lock in" the 2 outputs that aren't selected.

2) Disconnect the 2 bucket curl hoses from my loader valve.

3) Buy two short hoses to connect the curl cylinder outputs (from the loader valve) to the inputs of the selector valve. Your selector valve now has hydraulic power to pass onto it's outputs.

3) Take the two dangling hoses going to the bucket curl cylinders and connect them to the first set of outputs on the selector valve. At this point, when the selector valve is in position 1, your bucket curl cylinders are working as normal. The selector valve just acts as a pass-through, and is essentially not even there. Your loader joystick controls your plow or bucket like normal in this first position of the selector valve.

4) You have two remaining outputs from the selector valve. Run a line from one of these outputs to one of your single acting angle cylinders on your snow plow. Run a line from the remaining selector valve output to the second single-acting cylinder that angles your snow plow.

Now when you put the selector valve in position '2', it locks your bucket curl cylinders in place (to keep the front/rear angle of your plow wherever you set it) and now your left/right motion on the loader joystick controls your plow left/right angle. Your up/down motion of the loader joystick always controls the up/down movement of your loader arms with this setup.

 

[skyhook]

I get it, that little clip on the handle is what "locks" the handle in place,
you simply "unlock it" and re lock it to the other position when needed, is this correct.

 

[quadridermx]

That part is only leverage to switch positions. A fulcrum point. The lever stays in the spot you choose on its own. No need to hold it in place.