RK-12 — Realistic Kart (1:12 Scale)

🏁 RK-12 🏁

RK-12 — Realistic Kart (1:12 Scale)

A 1:12 realistic go-kart that brings the track into your living room.

- Designed based on real competitive go-kart chassis and geometry - Responsive, direct steering with controllable light drifting - Pure kart driving fun, even in small spaces

Design Overview

- Realistic Go-Kart Driving Logic RK-12 is not a typical RC car. It is a 1:12 scale realistic model designed after real competitive go-karts.

From chassis proportions and steering structure to overall dynamic response, the goal is to recreate the direct, agile, and highly engaging driving feel that defines real go-kart racing.

- Precise and Direct Steering Feedback The model fully replicates a real go-kart steering linkage system , delivering highly responsive steering with almost no perceptible delay.

Every steering input is clearly translated into vehicle movement, making control intuitive and “connected” to the car.

- Lightweight Structure, Rapid Acceleration An optimized micro gearbox combines compact size and lightweight design with a 1:10.8 reduction ratio , enabling higher wheel speed and stronger acceleration.

Even with the battery and control electronics installed, the total vehicle weight is only 185 g , resulting in crisp, agile vehicle dynamics.

- Go-Kart Steering — Not a Differential Real go-karts do not rely on differentials. Instead, they use kingpin inclination to naturally lift the inner rear wheel during high-speed cornering, allowing the kart to turn on three wheels .

RK-12 preserves this core behavior and further optimizes it for the short travel of RC controller joysticks, maintaining stability and control while still allowing smooth, controllable light drift.

- No Track Required — Pure Driving Fun Whether hugging table edges or drifting smoothly around a sofa, RK-12 delivers agile steering and controllable light drift, bringing pure driving enjoyment even in limited indoor spaces.

Printing Materials

- Main parts: PLA Basic - Tires: TPU 90A - Seat: PETG Translucent (Some real go-karts use semi-transparent seats, which provide an excellent visual effect) - Not recommended: PLA_SILK and PLA_METAL, as they may cause strength issues

Printing Notes

The printing content is divided into two separate 3MF files:

- Main Parts – use a 0.4 mm nozzle. - Precision Parts – use a 0.2 mm nozzle. small parts(in the precision parts 3MF file)

- precision parts containing small parts should be printed with a 0.2 mm nozzle - For enclosed printers, ensure adequate cooling to prevent heat buildup around small parts - Applying glue to the build plate is recommended to improve adhesion of small parts

Tire Printing （in the main parts 3MF file）

- Tires should be printed with TPU 90A - You may pull sufficient filament length off the spool without cutting it ，This prevents periodic extrusion instability caused by spool drag - Ensure the loose filament does not tangle during printing - Applying glue to the build plate is recommended （In testing, TPU 90A adhered more strongly without glue , making removal harder）

Support Removal

- Begin removing supports from the corner areas of the chassis - Refer to the slicer preview and avoid damaging structural rods - Assembly

- Please refer to the included PDF assembly instructions

Adjusting JSON Parameters in Cyberbrick

The RK-12.json file provides a set of default vehicle parameters. If you encounter the following issues, adjustments can be made as described below.

1. Vehicle Does Not Track Straight — Adjust Midpoint Offset

Check mechanical alignment first:

- Ensure the servo horn is aligned with the servo 0° position - Make sure the four screws securing the gearbox to the chassis are fully seated, but not overtightened Software adjustment:

- Path: RK-12 → Angular Servo → Midpoint Offset (-10.0° ~ 10.0°) - Adjustment logic: - Decrease value → wheels turn right - Increase value → wheels turn left - Recommendation: - Adjust the integer value first, then fine-tune the decimal

2. Adjust Steering Sensitivity — Servo Angle Range

Default steering range:

- Min. Angle ~ Max. Angle = 55° ~ 125° Adjustment guidelines:

- Smaller range → more stable, easier control - Larger range → more aggressive steering, suitable for drifting - Maximum recommended range: 35° ~ 145° (Exceeding this may affect servo operation) Suggested combinations:

- (65 ~ 115) - (60 ~ 120) - (55 ~ 125) - (50 ~ 130) - (45 ~ 135) - (40 ~ 140) - (35 ~ 145) Parameter paths:

- RK-12 → Angular Servo → Min. Angle (0°~180°) - RK-12 → Angular Servo → Max. Angle (0°~180°)

3. Wheel Spin After Battery Upgrade — Reduce Acceleration

If:

- You upgrade to a 3S battery (11.1V) - And experience wheel spin on smooth floor surfaces You may reduce the acceleration value: