I have been thinking about building my own offset tow behind mower. I have a swisher now but its getting beat to death in the fields I do. I'm thinking of taking a 3pt 60" finish mower and mounting a 15-20hp motor on it to power it and then rig up a tow system.
Some thought are:
How to drive and gear the system. Most small engines are governed at 3600rpm. I'm guessing peak power to be around 3000rpm, would need to gear that down to 540rpm. Chain or belt.
Tow system. The "trailer" type system with a pivot at the back of the tractor is what my Swisher uses. While its a simple system it drives me nuts whenever I turn a corner as it custs the corner in a tighter arc than the tractor leaving an uncut swath of grass. Having an arm mounted solidly off the back of the tractor would make it travel more in line with the tractor(like a 3pt implement) however no pivots need to betaken into account for forward and back and side to side.
Motor, vertical or horizontal shaft? Horizontal shaft would be easier to drive the input on a PTO. Vertical shaft motors are cheap to buy as there are tons of 15-20hp dead or cheap garden tractors with good motors in them that can be bought used for cheap. How could I turn the drive(and maybe gear it down) to drive a PTO input gear box?
Front or back? Since I'm fabbing anyway wouldn't it be better to mount it off the front where I can see it?
Anyone converted a PTO driven unit to self powered? If it goes well maybe I could mount a motor on a 3pt snowblower and use it on the front of my tractor.