grappel cylinder size?

Dale1995 · Feb 4, 2010

I have been building a grappel to help me clear a lot of brush and small trees. This will fit on a 2320 John deere. I am in the process of building the attachment points for the grappel arms. After looking at some cylinders on line, I see that I can purchase some cylinders for 2500 psi or 3500 psi. I am wondering if I will need the extra psi on such a grappel. Also what size shaft should I be looking for 1", 1 1/4", or 1 1/2". My tractor is only cable of lifting about 1000 lbs. It is a 200cx loader, but it will be much faster than clearing up this lot by hand (and more fune too

) Any suggestion of what to buy or where to buy would be greatly appreciated! Also any brands/types to stay away from would also be great. Also I will post pictures shortly of my progress.

kennyd · Feb 4, 2010

The PSI listed is the MAX the cylinder should be operated at, not what it develops...

A 1" rod cylinder with a 1 1/2" bore and 8" stroke is about right for a grapple. Look around the Surplus Center for good deals on cylinders and other hydraulic needs.

J_J · Feb 4, 2010

Have you built the grapple yet.

Something like this if the mounting distance from pin to pin is adequate.

https://www.surpluscenter.com/item.asp?UID=3508020416414429&item=9-7602-08&catname=hydraulic

Dale1995 · Feb 4, 2010

I have the frame all built and the grappel arms made, but have not attached any mounting brackets for the cylinder yet because I am wondering if I should have a bracket on each side of the cylinder or just a thicker single piece of steel for the cylinder pins to fasten to. I guess there must be pros and cons both ways? Whats is everyone opinion?

J_J · Feb 4, 2010

Dale1995,

Are the points on the grapple touching the tines on the bottom, or did you build so the grapple tines go between the lower tines, for more squeeze action? For the open and closed pin position, you need to set the grapple at the desired opening, and then set the grapple at the max closed position, and measure the distance from pin to pin. That will give you the overall length of the cylinder in the extended mode.

You can use PVC pipe, one pipe inside the other to check cylinder operation from open to closed. Just put a hole in each end, and open and close the grapple, and mark the limits.

It will depend on the cyl end pieces as to the mounting lugs.

Dale1995 · Feb 5, 2010

I built this so the grapple tines go between the lower tines, and have not welded anything up yet. I would like the grapple to open as large as possible. I have mocked up one of the hydraulic brackets from some wood to see if it will work properly, much easier to cut wood then steel, then I will use my mock up as a pattern. Sounds like a lot of work, but I enjoy designing these types of items. My last thing to do will be to add a third circuit to my loader, to run the grapple. I have looked at a few options and would like to have the best with the least price!

kennyd · Feb 5, 2010

Dale1995 said:
I have looked at a few options and would like to have the best with the least price!

So is everyone else

J_J · Feb 5, 2010

This selecter/diverter valve from Surplus Hyd, would work for your purpose.

https://www.surpluscenter.com/item.asp?UID=3516020513353108&item=9-5117-A&catname=hydraulic

What kind of cyl do you want, welded, tie rod, single clevis, double clevis, swivel eye, pin hole, cross tube. etc? Welded cyl are the strongest, but you really don't need real strong.

J_J · Feb 5, 2010

One nice feature about the selector valve above, is that the curl cylinders will operate normally, if hooked up to the valve correctly. To shift the valve to the grapple, only takes a single push button to apply power to both solenoids, causing both solenoid to shift modes. The setup for valve is, one spool normally closed, and the other one is normally open. When you press the button/switch, the spool action reverse, and the hyd output switches to the other cylinder.

Dale1995 · Feb 5, 2010

is there anything else I would need besides hoses? I assume that I will have to fabricate a mounting bracket.... how well do these valves stand up to the weather or do they need to be mounted in a "protected" location? You must have read my mind, the grapple I am building looks exactly like the picture on the left you posted....and better yet its green!