Few pictures of something you may find interesting:
A neighbourgh and friend is doing lots of road maintenance, such as cutting trees branches up to 9m high, or maintaining sharp ditches.
Many years ago, he modified an old Deere 5460 to get a tree branch cutter. Nothing was available at this time.
The cutter arm and cutter head is a french built. The arm is made to go on a farm tractor, but it is very hard to drive with the arm on the back. The whole thing takes only 80-100HP to run when going trough something big. Maintaining ditches, power usages can be very low on average.
The chopper was worn out. He put a Deere 239 engine in it instead of the 619, in fear of wearing out the Deere 619 because of no loads, and thinking fuel economy would be better.
This setup worked flawlessly.
Then he modified a Deere 5820, but he kept the 619, but made the chopper fan shaft run the hydraulic pump for the cutter arm at an engine speed of 1100 RPM.
That way, the 619 seep fuel.
His most recent and most used is a Deere 6810. That thing also run at 1100 rpm to run the big Noremat arm. That 6810 has 14000Hrs and climbing (fast, that neighbourgh is the local SVCummins, and can clock 85Hrs in one week on the 6810). Only issue with the 6810 was electrical problems when he got the machine. A friend rewelded everything and this has hold for the 10000 hours of use with the brush cutter.
The 6810 is only doing 2.2 Gal/hours of brush cutter. That is very low!
I think this is due to the very big engine for HP required, and the use of a very low RPM, that reduces friction losses, gives more time to the fire in the cylinder to expand before the connecting rod gets thrown too far, etc...
There is no hydro lever, the hydro cable is connected directly to a LH pedal that you push forward or rearward. That is because you always have to control the cutterhead with the joystick. Someone has to be very good to control this. His grandson can drive the 5820 and do a nice job at 11 !
Below is a picture of the 5820 joystick. 6810 is pretty much the same.
A neighbourgh and friend is doing lots of road maintenance, such as cutting trees branches up to 9m high, or maintaining sharp ditches.
Many years ago, he modified an old Deere 5460 to get a tree branch cutter. Nothing was available at this time.
The cutter arm and cutter head is a french built. The arm is made to go on a farm tractor, but it is very hard to drive with the arm on the back. The whole thing takes only 80-100HP to run when going trough something big. Maintaining ditches, power usages can be very low on average.
The chopper was worn out. He put a Deere 239 engine in it instead of the 619, in fear of wearing out the Deere 619 because of no loads, and thinking fuel economy would be better.
This setup worked flawlessly.
Then he modified a Deere 5820, but he kept the 619, but made the chopper fan shaft run the hydraulic pump for the cutter arm at an engine speed of 1100 RPM.
That way, the 619 seep fuel.
His most recent and most used is a Deere 6810. That thing also run at 1100 rpm to run the big Noremat arm. That 6810 has 14000Hrs and climbing (fast, that neighbourgh is the local SVCummins, and can clock 85Hrs in one week on the 6810). Only issue with the 6810 was electrical problems when he got the machine. A friend rewelded everything and this has hold for the 10000 hours of use with the brush cutter.
The 6810 is only doing 2.2 Gal/hours of brush cutter. That is very low!
I think this is due to the very big engine for HP required, and the use of a very low RPM, that reduces friction losses, gives more time to the fire in the cylinder to expand before the connecting rod gets thrown too far, etc...
There is no hydro lever, the hydro cable is connected directly to a LH pedal that you push forward or rearward. That is because you always have to control the cutterhead with the joystick. Someone has to be very good to control this. His grandson can drive the 5820 and do a nice job at 11 !
Below is a picture of the 5820 joystick. 6810 is pretty much the same.