Scalextric C122 Mini Clubman 1275GT Replacement Chassis

thingiverse

Having recently acquired two original Scalextric C122 Mini's for my slot car collection, I was somewhat let down by the performance of the original chassis. Unfortunately, this is typical of many Scalextric cars from that era with their high center of gravity, front wheels that flop excessively and a tendency to de-slot easily. However, I do love the classic Mini look and decided to develop this drop-in replacement chassis. The new chassis fits the original body without any modifications and mounts into the same front and rear clips as the original. The original interior and driver fit directly onto the mounting posts in the new chassis. The major design improvement is lowering the chassis and motor closer to the track, which brings down the center of gravity. The front axle is also adjustable with M3 5mm grub nuts top and bottom. I prefer to have the front wheels on the track, and the grub nuts allow you to fine-tune the wheel position to suit your guide and braid. The running gear re-uses the original model's components including the rear axle with plastic bearings (which simply clips into the new chassis), front axle, and all four wheels. The motor is a standard Scalextric Mabuchi motor and pinion gear (this replaces the original Johnson 111 motor). There is also a location for a magnet (20x5) between the motor and rear axle to improve traction. The clips for the rear plastic axle bearings may need a small amount of filing to allow wheels to spin freely. Simply do a test fit and gently file the openings larger if required. The front guide post will suit either a Slot.it long clip-in guide or a standard Scalextric guide. The Scalextric guide will require the circular spacer on the underside to be trimmed off with a sharp hobby knife as it is thicker than the Slot.it guide. The guide hole may need some careful filing or running a drill bit through to allow the guide to move smoothly. This will vary depending on the exact guide chosen. To install the body onto the chassis, it is necessary to flex the chassis considerably to get the headlights to slip into the body. This may take more force than you initially think, but I haven't broken a chassis yet and the body needs to be a tight fit so as not to fall off in a crash. When setting up the chassis for printing, a support structure will be required otherwise the overhangs will not print well. The Rhino 3D model is also included for anyone who may want to modify the design. The replacement chassis has greatly improved this classic car and makes it much more capable of keeping up with more modern Scalextric models. All feedback welcome, and happy racing!