PPPRS construction update
Progress has been slow. in the past week we’ve gotten all the requisite parts, but have been lacking in time to assemble it all.
all 4 wheels are now on the kart, and the original body fits surprisingly well. Fronts are 4″ steel wheels from Harbor Freight, $6.99 apiece with some real bearings in there. Rears are 5″ azusalite nylon wheels from a member’s gravity car.
some of our drivers, too, fit surprisingly well. We’ve had to widen the roll cage a bit to accommodate adults, and we removed some of the crossbars from the existing ‘rollcage’ so they wouldn’t interfere with seating position, but aside from that the exterior of the body is just about completely stock.
the body rests on a simple frame of angle iron. It supports our vertical loads well, and is torsionally flexible. This is good because it will serve as rudimentary suspension and will prevent the castered front outside wheel from coming off the ground under cornering. The front wheels have caster so they experience negative camber during cornering, which should allow the tire to maintain a proper contact patch. While we expect understeer due to the relative dearth of weight on the front axle compared to the rear (and the better tires with a larger contact patch on the rear), caster should help mitigate it.
Power will be delivered to the rear wheels from the EV warrior motors via #35 chain. Attached to the rear wheels are 60-tooth sprocket drums. Since these are also part of the braking assembly, their cost is not counted toward our $500 target. The donor kart did not need a chain drive so we had to remove the original brake drums to make way for the new ones. brakes are azusa 4.5″ drum assemblies, also from the gravity kart. they will be actuated by a hand lever on the steering yoke.
We even have comfortable seating worked out! A member brought over many, many office chairs so we a good selection to pick out the sturdiest, perfect-fitting seat. with the nature of the seat and the posture, the kart is surprisingly comfortable to sit in and feels stable as well. The body has been cut out to lower the bottom of the seat to within an inch of the minimum ‘axle height’ rule. this, combined with the slightly laid-back posture of the driver, should keep the CG as low as we can get. perhaps we won’t need the frame extensions we’ve kept on for provisional wheelie bars!
Now it’s on to drivetrain and steering. we hope to have the thing rolling by the end of Wednesday night