Here’s something I’ve been working with Team 228 on-and-off-again over the past few months on, as an off-season prototype chassis based upon our 2007 sheet metal chassis with various improvements across the board. The frame is Safety Orange powdercoated .125" 5052 Aluminum, manufactured on CNC turret punch machines at our sponsor’s machine shop (which is owned by the father of a team alumni). The sheet metal design is nice because it eliminates so many “intermediate” parts, such as gearbox standoffs, gusset plates, etc. and all their related hardware into a single component such as the gearbox body (single piece of aluminum).
Configuration: 6WD Live Axle, Direct Drive Center, 35p Chain, AndyMark aluminum sprockets (yeah, I know 25p is lighter and works, but the students want to use 35p).
Speed: About 9.5 ft/sec under normal load.
Gearbox: Single speed, uses AM gears. 50:12 first stage, 45:19 second stage. Second stage identical center-to-center distance as Toughbox second stage, and is thus able to choose from the three ratios offered by AM. 1"x1"x1/16" aluminum angle can also be attached between the two gearboxes to the PEM nuts pressed into them (visible on the sides and top flanges).
Wheels: 6x 5"x2" Performa Colson with knurled aluminum inserts with 1/8" keyway broach pressed into wheels. (Hex broach preferable, but still a season or two worth of capital improvements away).
Final SolidWorks weight with all hardware: 37.07 lbs