Proper Grapple usage

[Rickklem]

While I wait for the dealer to get a gear drive L4701 in stock, I have been checking out all if the YT video from Messicks. (Neil).

Since I am getting a grapple from Construction Attachments, I watched a video Neil posted about the pressures that can be pushed back through the hydro lines by using the grapple in the wrong way or over working it.

The way he made it sound, was if something like a log or rock forces the cylinder of the grapple open or applies pressure to it, that it could spike the pressures upward of 6000 pounds on a hose that is only rated at 3000. He said that it is easy to damage the hoses, valve or a pump with these pressures.

Has anyone seen this video and what are your thoughts on it?
I plan to use it to pull downed trees out of the brush by grabbing them on the end and backing out. Could this generate this condition that he talks about?

Is this something that I should really be concerned about?

He did say there is a check valve of some type that could be installed to prevent the feedback spike. I don't know that much about hydraulic's yet, so I don't know what to ask for or where I would need to install it if I did need one. And if it's a problem then why isn't one installed on the grapple to begin with?

Just wondering if this is a concern
Rick

 

[mcfarmall]

A friend of mine has a Woods back blade with the hydraulic angle adjustment. It has a cartridge style relief valve (Sun Hydraulics, et al) in a manifold mounted on the frame of the blade. If you strike a solid object with the end of the blade it allows fluid to pass from one port of the cylinder to the other preventing hose breakage.

It's basically a hydraulic overforce mechanism.

 

[i7win7]

I plan to use it to pull downed trees out of the brush by grabbing them on the end and backing out. Could this generate this condition that he talks about?

Should be ok unless roots are still attached (in ground) and you're rocking tractor trying to break them off

How not to use grapple videos

 

[Dave_eng]

Has anyone seen this video and what are your thoughts on it?
I plan to use it to pull downed trees out of the brush by grabbing them on the end and backing out. Could this generate this condition that he talks about?

Is this something that I should really be concerned about?

He did say there is a check valve of some type that could be installed to prevent the feedback spike. I don't know that much about hydraulic's yet, so I don't know what to ask for or where I would need to install it if I did need one. And if it's a problem then why isn't one installed on the grapple to begin with?

Just wondering if this is a concern
Rick

 

[Dave_eng]

I have watched the video and use it to try and explain to owners with pallet forks and bucket mounted booms how easy it is to generate pressures which are high enough to damage cylinders.

The back blade valve mentioned by mcfarmall works by allowing the blade to move away from an obstruction. I do not know how to use a similar valve with a grapple.

Factors of safety are part of any engineering designed piece of equipment and awareness of the risks means you are not blindly over stressing your equipment.

Be cautious and all will be OK.

I found this info on the type of valve which is used to protect pivoting blades.

Dave

 

[Nicfin36]

It can't be that big a deal. I too saw the Messick's video. But, with so many grapples in use now, I don't recall any issues with hydraulic damage.

But, to echo Dave, pay attention to what your doing and you shouldn't have any issues. I have pulled trees with mine. No problems so far. I try not to do anything stressful with the grapple with it fully open or with the grapple in the full dump position.