Prior to this project the only welding I'd done was sticking together a couple chopped up bike frames with a rented MIG welder. This lack of welding experience, an engineering degree, and a healthy distrust in the welds I could make, led to a bit of over design and planning. Just a bit. While the end result can probably withstand most anything thrown at it... it is heavy.
Specifications
Length: 11 feet
Width: 6.5 feet
Height: 7 feet (to top of seat backs)
Drive: Four person pedal
Weight: 1100 lbs
Equipment
Lincoln-Electric Power MIG 180C
Metal band saw
Bench drill press
Cut-off saw
Grinder
Misc power hand tools
Materials
Mild steel tubing (.065" and .120" wall)
3/8" mild steel plate
36" id HDPE plastic drainage pipe
Golf cart spindles and rims
Misc. power-train components: #40 chain; sprockets; pillow blocks; etc.