Building a RC mower for steep hill, 4x4 with 4 wheelchair motors. Plan to start with skid steer, is there a formula for the dimensions? I would assume a long and skinny would have a horrible time skid steering. So is there any formula so my dimensions to not cause serious skid steer problems.
Look up Bobcat dimensions and scale them down?
The larger the wheel base, the more energy is wasted with skid steering.
I get the efficiency (i.e. drive_force / (friction + drive_force)) =
axle_length / (wheel_base + axle_len)
From similar triangles. This is turning on the spot, not while moving (which gets more efficient as some of the power is useful forward motion, not just turning).
One issue to think about is damage to the lawn from skidding - smoother tyres might be good to reduce this.
Cut up the wheel chairs and used them with some scrap steel. 32 inches long, 29 inches wide at the tires, rear tires are 31 inches wide, just how it worked out with the wheel chair parts. Front articulates a few inches from the wheel chair parts. Tires are not smooth, 11 inch snow tires. Man did it tear the grass up, but I am in FL with weeds and real soft sand so I would expect that. My goal is for use in the mountains on steep terrain with hard clay that hard to even walk on, so I need 4wd and traction. I think I am going to find a cheap mower and throw under this and see what happens. I put one of the wheel chair bases on top with the batteries and smooth wide turns were not bad at all. Sharp turns were rough looking, but I guess that is skip steering, has to skid.! I tried to keep it close to square as that is what bobcats are.mockup|666x500