I knew I would need one when I planted the 300 meters of hedge 5 years ago. I didn’t know that they’re so expensive. I bought the old tractor for 5000 euros, and a second hand cutting attachment would cost at least as much again.
So I made my own.
It needs to be able to cut 3 meters [10 feet] out from the tractor at 3 meters [still 10 feet] high. I also wanted it to work forward, backwards, and on either side of the tractor. Vertical or horizontal of course.
I bought the cutting blades, a 2.4 meter lead screw, and 2 hydraulic motors new. 3 hydraulic cylinders I had lying around, most of the rest of the machine is made from scrap.
I couldn’t source a thin hydraulic cylinder 2.2 meters long, so I opted for a long screw driven by a little hydraulic motor to extend the boom.
Since the whole thing wants to flip over and rotate, I had some trouble coming up with a design for rotating the blade where the linkage wouldn’t be in the way; so I used a rather elaborate setup where the actuating linkage is all the way at the other end of the boom, and a telescoping torque tube will swing the blade through a pair of gears. The 2.4 meter long extension screw [actually a 22mm lead screw] is inside that.
So when the boom is retracted, there’s a screw in a 1” pipe in a 1/14” pipe in a 2” pipe in a 3” pipe in a 4” pipe.
Simple really.
I made a webpage with build photos here; http://aljezurfarm.com/hedge_cutter_project.htm
I didn’t really explain the whole machine, but you can figure it out.
And here’s a video of it working;
