Saturday, July 12, 2008
Pedal Tractor Progress Report
The extended bicycle frame was welded to the main axle housing a couple of weeks ago. Last week I made the jack shaft and mounting brackets separately and then today I welded the assembly to the main axle housing. I designed adjustable seats out of two old plastic chairs. I mounted the seats and put the three bicycle freewheels and a small main drive gear on the jack shaft. The gears and freewheels aren't locked down yet. I need to make the pedal parts and then I can lock down all the gears after I line everything up.
Below is a photo of the jack shaft mounted to the main axle housing. The jack shaft is 3/4 inch diameter solid steel. The main axle is 1-inch diameter sold steel. The main axle housing is 2-inch schedule 40 pipe.
The main shaft is a solid axle from wheel to wheel. This is turning out to be a problem. It's really hard to turn the tractor with both big wheels locked to the shaft. I think I will have to cut the shaft and make it a one-wheel-drive pedal tractor. The other big wheel will just roll along. I am contemplating putting splines on the inside ends of the split axle and then making a spline sleeve that I can slide from the drive axle over the free axle in case I need two-wheel drive.
There is still a lot to do. There will probably be a lot of bracing needed. I won't know exactly where until we give it a test ride and see what's too flexible. I also want to weld on cup holders,
umbrellas and shade canopies for all riders, and maybe mounting brackets on the back for a sound system or maybe fire cannons?. Then will come paint, decorations, and maybe lighting for night travel.
I'm not the only person making strange pedal-powered tricycles. In fact mine is fairly tame compared to the ones made by a group of people who call themselves the Department of Spontaneous Combustion. They have made some three-wheeled pedal powered vehicles that shoot fire. Some of these have two big wheels in front and a single wheel in back. See a smaller one here.
And this is a link to a spectacular photo of one of their large ones.