Question about Kubota Third Function Valve Operation

[Fxfymn]

Not only does the HST keep the engine speed up, but the Tier 4 "asks" you to run at a higher RPM as well. Of course if I do run it at a lower RPM I can instantly throttle up using the switch on the loader joy stick. If they put any more switches on the joy stick I'm going to have to have another thumb grafted onto my hand to operate them.

One thing about my configuration that may well be contributing to the issue is that my "grapple" is really more like a thumb on a backhoe. it uses a single 2" cylinder which I'm sure is one reason why it is so quick to react. As I said my first step is to restrict the flow and I'll see what happens. If not, the hoses from the rear are already in place and all I need to do is hook them to the existing hoses that run up the loader to the bucket. In fact, I may end up switching between the valves depending on what I am doing; 3rd function for brush, moving logs to the landing, etc and remotes for loading the logs into the trailer, picking up things like my auxiliary fuel tank, etc. We'll see.

It's kind of funny in a way; this is my fourth CUT and is the one I always thought I wanted. Now that I'm into it I don't know if I should have stuck with the simple old stuff.

 

[MtnViewRanch]

With your 2" dia cylinder, start out using the restrictors sized at .030. That should be good for you.

 

[Fxfymn]

With your 2" dia cylinder, start out using the restrictors sized at .030. That should be good for you.

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Thanks, I'll give that a shot.

 

[Fxfymn]

I installed an adjustable flow limiter into the circuit and it helps, but it is still a pretty hard open and close. I'm going to try it, but I'm not impressed.

 

[MtnViewRanch]

I installed an adjustable flow limiter into the circuit and it helps, but it is still a pretty hard open and close. I'm going to try it, but I'm not impressed.

You should be able to stop the flow if you are using an adjustable restrictor. So the hard open close is not understandable. Just close the restrictor valve more.

 

[Fxfymn]

I closed it enough to keep the system operating correctly. If I close it down more one of the solenoids will not cycle off unless I operate the switch in the opposite direction.

 

[ovrszd]

I closed it enough to keep the system operating correctly. If I close it down more one of the solenoids will not cycle off unless I operate the switch in the opposite direction.

Be wary of this. When you close enough to restrict flow considerably you are placing load on your relief valve. Might hear a slight squealing when using. Same with restrictor fittings. The flow capacity of your system is going somewhere. It doesn't simply not flow. So if it's not going toward the load, it's dumping out the relief valve. Too much restriction and repeated use can cause heat in the system and stress on the relief valve.

 

[Milo]

Be wary of this. When you close enough to restrict flow considerably you are placing load on your relief valve. Might hear a slight squealing when using. Same with restrictor fittings....

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

 

[MtnViewRanch]

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

Use a diverter type valve and not have these concerns.

 

[ovrszd]

So is there any good fix or remedy? Maybe a longer travel, variable switch that can be feathered instead of what I take it to be open-off-close switch? I've been following this thread as I really have use for a grapple. But I can see how the abrupt opening and close could be very aggravating.

The restrictor devices are the best you can hope for. And they work fine if properly used. Just be careful about pinching down the flow too much.

I don't use restrictors on my Grapple. It used two 2"x8" cylinders. My M9540 has considerable flow. They can be slammed open or closed. If I'm wanting to be gentle I can "tap" the joystick buttons and regulate it pretty well. Just takes practice.

To have a Grapple is worth the learning curve of controlled use.

For clarity, understand, a diverter system uses your "curl" function on the FEL to operate the Grapple. So it has delicate control by a steady hand on the joystick. What you sacrifice is the ability to do both functions at once.

The system we're discussing here is operated by electric over hydraulic valves. They only know "open" "closed". The gain is multiple simultaneous functions.