Tree shear

[jamtuc]

Hi folks,

I am new to the site. I am palnning on building a tree shear for my FEL I haven't seen any plans. I have some hydraulic questions.

1. Can I split off the current FEL valve for the Shear?

2. Will my Hydraulic pump support another cylinder?

3. What about overheating ?(638 said they didnt think so)

Any advice is welcome. I have a B1700 HSD with FEL.

Ive been reading the forums for a little while I am prepared with pencil and paper to take notes. Have at it fellas I'm here to learn.

Thanks

 

[radman1]

I have a 14" dymax tree shear called the ranch ax and it is a 1600# beast. I think it is the cadillac of skid steer tree shears. A friend of mine has part time business and has tried different companies, and Dymax makes in the best in his opinion. Couldn't hurt this thing. I push and pile trees with it, grab cut down trees and move them etc. Two, 8" cylinders with 3" rams. Will cut a 14" cedar but not 14" hardwood. Will cut about 11-12" hardwood. I run this on a Bobcat S300 which has about 19 gpm flow and 3300 psi and I wish the flow rate was even higher for more optimum capacity. I sheared about 400 trees last weekend in about 7 hours. All different sizes from 1" to more than I could chew off. Only got stuck once. I made a spray kit for mine to spray the stumps of hardwoods with Pathway after cutting to stop regrowth. Push button in cab to run electric pump that sprays the stump.
What kind of trees and diameter are you considering? What is the lift capacity of the FEL? What is your hydraulic flow rate or psi? For the small size of tractor, you maybe limited to 4-5" diameter trees at the ground level. Tree shears take a lot of abuse and tremendous force on the shears and equipment. I am afraid your B1700 won't be able to lift one built heavy enough for anything much bigger. If you build one, be sure to make a brush guard on the unit to protect the grill/tractor.
My brother is a state forester and they made a tractor FEL prototype many years ago. It seemed very well built with 6" farm implement type cylinders, 6"x6" base frame, 4x4" brush guard and they still had mulitiple instances of breaking the frame or cylinder attachment with the 2500 psi of farm tractors.
I wouldn't be concerned about overheating the hydraulics. The hydraulics don't run all the time and the actual heavy use of the cylinder if relatively breif. You will need valve controls to lift the FEL, tip/curl the shear and another control to open and close the shear hydraulic. 3 valves needed. You could use just one hydraulic cylinder on a moveable shear which would cut against a fixed shear. This will imensely help your cycle times on opening and closing the shear. However, one cylinder put more stress on the loader because it will frequently push the front of the loader and tractor to one side as the cylinder closes.
It maybe much easier to rent a small to mid sized skid steer and shear for limited use. A skid steer can do a lot of trees in a day. You don't need a big skid steer for shearing. Smaller sizes actually are preferred and with tracks, they can go most places.

 

[jamtuc]

Thanks for the information. A little more information my FEL says 600 lbs. I already have the 4 way valve for the FEL. Can I use a diverter valve from one of the lines to operate the shear? I am not sure about the terminology for the different valves. Since I would not be using the other stuff while shearing. What size cylinders and hoses do I need. I know where I want to be but don't want to screw up more than I can fix getting there The trees I'll be shearing are at most 4" to 5" max. Most are way smaller. A big cedar thicket.

 

[radman1]

To be honest, it would probably take an engineer to answer your questions. Still don't know your hydraulic psi. It is still probably going to require more steel than you can lift. The shears are a very high grade to maintain sharpness and not the typical mild steel. Shears would need to be 7-8" length, each shear probably at least 1/2-5/8" thick and 4" wide. Mine are 3/4-1" thick and 18-20" length. The base has to be extremely strong and resist all twisting. If the shears don't meet perfectly each time, they will become off set and not shear off completely. Shears have to be adjustable after sharpening so they can close completely. For trees that small, your probably much better off getting a chainsaw and 3 sharp chains. I could cut those off an be on the next two before your shear could take one down. Shears on FEL also don't work great because the tractor hood blocks the view of the shear and the shears want to push the tractor back as they close.
A 4" diameter cylinder at 2500 psi creates over 31,000 lbs of force. It takes a lot of strength to hold that together.

 

[kennyd]

I just looked up the SPECS for your machine, and I have to agree with Radman, I don't think your tractor is up to the task for a sheer, especially one to do 4-5" trees.

 

[sandman2234]

One shear I saw is one that mounted on the 3pt hitch. Kind of a a neat attachment. That is what started me gathering parts to build one with. After I bought the blades, the deal on the property I was to clear fell thru, so unless I get another offer, I probably won't ever get around to the shear.
Mechanical advantage/disadvantage has to be considered when building one, in addition to the psi/output of the pump and the diameter of the cylinder. J_J has a nice shear for his powertrac, and I am pretty sure he built it. Sure beats having to wade into a briar patch with a chainsaw trying to cut a small tree.
David from jax

 

[sandman2234]

I tripped over my blades today. I had a tape handy, so I thought I would measure them. They are 3/8" thick, about 18.5" long, and about 4 inches wide. They are made by Simmons, the same people that make files and saw blades. I tried to find some more on ebay, but the seller has quit selling with over a quarter million feedbacks. They will probaby be back, or find some other way to sell the stuff.
David from jax