The Cart                                                                                             

Engine and compressor  rear view.

I had most of the components to make the rickshaw cart already on-hand, so it's construction went pretty fast. I mounted a 2 hp Briggs and Stratton  engine and an air compressor onto a 1.5" x 10" x 24" plank and enclosed the unit inside a plywood box. 

Thin wall conduit frame.

I made "S" shaped offset bends in eight foot sections of one inch thin walled conduit and secured them to the bottom of the box. I welded ¾" black pipe fittings into the ends of the conduit so that the conduits became almost air tight. Small leaks in the welds were plugged by applying vacuum to the conduit while painting the welds with a two-part resin. Very sturdy wheel barrow wheels on a ¾" steel axel were bolted to a ¾" thick piece of plywood. This plywood and the attached wheels are connected to the bottom of the cart box with a pair of heavy–duty drawer slides. This allows the cart wheels to be moved forward or aft, which changes the balance point of the cart. The wheels are easily locked in place at a desired location.

Break pedal and emergency break.

A foot pedal break, pulls a cable to rotate a small plank that rubs on the wheels to stop them from turning. There is also a small  foot activated lever that engages a ratchet device that makes the break foot pedal act like an emergency break.  The break system works excellently.

Right armrest.

Mounted on the right armrest is the engine throttle, the compressor pressure gauge and a knob to adjust the compressor's pressure.  Pressure is regulated by allowing excess compressor pressure to escape past a rubber cap held down by a compression spring.  I can adjust the force on the spring to get working air pressures of 20 PSI to 100 PSI.  The micro controller and its controls will be installed  under/on the left armrest.

Finished cart.

I painted the conduits black, stained the wood golden and glued some fabric to the front of the plywood box. The space under the armrests is enclosed by fabric covered cardboard. The backrest is garden shade cloth sewn onto a bent ¾" conduit frame. I made a pillow for the seat.

I am very happy with the look and feel of the cart. Not counting the engine and compressor, the parts I bought cost a little over $100. The curb weight of the cart is 172 pounds. It is time to start thinking about robotic legs.