Grapple What's needed for a grapple?

[TractorGuy]

Self explanatory-will be buying a scut within the next 6 months with a fel. Really falling in love with the idea of also buying a small grapple with it.
My questions is-when you swap out the bucket with the grapple, are the existing hydraulic connections not enough? Is that what the "3rd function" is for? I guess, the tractor hydraulics do the lifting and curling, but 3rd function is to open and close the jaws?
One of the tractors I'm looking at is the RK24, which comes with a set of rear remotes. Could you run lines from the grapple to the back and use the rear remotes?
Sorry if these are stupid questions. I've had a bx1800 for 15 years, but I've never had a fel.
REALLY looking forward to an upgrade as soon as i pay off the wife's car.
Thanks in advance for any answers.

I understand that, just wanted to know exactly what a 3rd function was and what it's used for with the grapple.

Yes the third function is to open and close the grapple clamp.

In the absence of a true third spool some people install a diverter valve that shifts the hydraulics used for the bucket curl to close and open the grapple clamp. Not sure why you would need to perform both functions at the same time but some folks seem to think the diverter valve is a limitation. My understanding is the RK thrid function is a true third spool when ordered through them but make sure when you order if that concerns you.

I will be outfitting my JD4310 with a grapple next year. It has an unused third spool but I will most likely install a diverter valve and save the third spool to use for a hydraulic top link. I think a button on the loader knob will be more convenient than another lever and I don't see any reason to use the clamp and curl simultaneously.

Some factory setups will have a twist function on the loader control for 4in1 buckets or grapples. Not sure how the RK system works but that would probably be the most convenient way to operate a third spool valve.

 

[k0ua]

Keep in mind that especially with a smaller SCUT the the total flow of fluid will be low as say compared to a 40 HP CUT. What I am saying is even if you have a "true" 3rd function electric over hydraulic valve installed, you likely will not have enough flow from the power beyond port on the loader to operate if if you are using the curl function on the loader valve. The loader valve will be "upstream" of the 3rd function valve, and will likely use most if not all of the flow from the hydraulic pump. My point is a diverter valve installation will likely result in about the same operation in reality as the 3rd function. Neither likely to curl and clamp at the same time.

 

[k0ua]

And whether the clamp function of a grapple jaw must operate at the same time as the curl function is somewhat a moot point for a homeowner. Yeah I can see it on a skilled operator on a bobcat, sure, but a homeowner typically does not "need" to operate both functions at once. I typically open the jaws before I approach say a pile of brush.

Now I drive up and curl down, coming down on the pile and crushing it down as much as I can to pack the jaws, full of material, THEN close the jaws. At this point I am not actually using fluid "upstream" in the loader valve so the fluid flow is passing out the power beyond port on its way to "downstream" valves and on to the three point lift and into the tank.

After the jaws are closed, I will lift and curl the wad and move on the drop point. Some would argue that second to close the jaws is lost operation time, and I guess so, if you are making money with your machine, but if you are cleaning up your yard, it is no big deal. My rear remote stick is very convenient to operate with my joystick hand, and is adequate for me.

 

[eubie5]

Thanks for all the advice

 

[goeduck]

Now I drive up and curl down, coming down on the pile and crushing it down as much as I can to pack the jaws, full of material, THEN close the jaws. At this point I am not actually using fluid "upstream" in the loader valve so the fluid flow is passing out the power beyond port on its way to "downstream" valves and on to the three point lift and into the tank.

After the jaws are closed, I will lift and curl the wad and move on the drop point. Some would argue that second to close the jaws is lost operation time, and I guess so, if you are making money with your machine, but if you are cleaning up your yard, it is no big deal. My rear remote stick is very convenient to operate with my joystick hand, and is adequate for me.

^^^ exactly how I do it.

 

[ovrszd]

I use all 3 functions together every time I use my Grapple. But, as James mentioned, gpm flow comes into play. I have enough flow to power all three at once.

 

[k0ua]

I use all 3 functions together every time I use my Grapple. But, as James mentioned, gpm flow comes into play. I have enough flow to power all three at once.

Yeah, but you have a "big boy" tractor. Many little SCUTS are doing good just to operate the lift cylinders, most won't run lift and curl at the same time.

 

[Lowcountry Rebel]

Yeah, but you have a "big boy" tractor. Many little SCUTS are doing good just to operate the lift cylinders, most won't run lift and curl at the same time.

my 60 HP won't lift and curl at the same time. Maybe because it is a self leveling loader?

 

[ovrszd]

Yeah, but you have a "big boy" tractor. Many little SCUTS are doing good just to operate the lift cylinders, most won't run lift and curl at the same time.

Yep. Even my Kubota L4400 struggled with that.

 

[ovrszd]

my 60 HP won't lift and curl at the same time. Maybe because it is a self leveling loader?

I believe it's in the valving. Not an expert at all but that's what I've understood from other hydraulic discussions here on TBN.