OpenRC 4-Wheel Drive Go-Kart with Ackermann Steering

OpenRC 4-Wheel Drive Go-Kart with Ackermann Steering

The model is inspired by Lego Go-Kart 1972: https://www.toysperiod.com/lego-set-reference/technic/model/race/lego-1972-go-cart/

The custom electronics has been designed around the Esp32 processor. The controlling software can be found in github at: https://github.com/projunk/RaceCarESP32

Two configurations are currently supported:

1. BR2830 850Kv motors with 2S Battery (NANO_TECH 4200)

see e.g.: https://www.amazon.in/Generic-Racerstar-BR2830-Brushless-Airplane/dp/B07PCMDCMF

Theoretical Top Speed: 113 Km/h

      2. 5010 360Kv motors with 4S Battery (MULTISTAR 4000)

see e.g.: https://nl.aliexpress.com/i/32479766898.html?gatewayAdapt=glo2nld

Theoretical Top Speed: 96 Km/h

The scale factor compared to Lego parts is 3.0

Printed Parts (already scaled):

• BatteryHolderPlateStraps_MultiStar4000.stl (2x) or BatteryHolderPlateStraps_NanoTech4200.stl (2x)
• ChairHolderHingePlate.stl
• ElectronicsBrick.stl
• ElectronicsPlate.stl
• Plate_1x2.stl (2x)
• Plate_2x8.stl
• Rim_motor_2830.stl (4x) or Rim_motor_5010.stl (4x)
• SlickTire_2830.stl (4x) or SlickTire_5010.stl (4x)
• servo_connector.stl
• technic_brick_ackermann_left.stl
• technic_brick_ackermann_right.stl
• technic_brick_motor_left.stl
• technic_brick_motor_right.stl
• technic_brick_servo.stl
• technic_pin_with_friction.stl
• technic_plate_toothed_end.stl (2x)
• technic_plate_toothed_end_ackermann.stl
• technic_steering_arm_motor_M8_left.stl
• technic_steering_arm_motor_M8_right.stl

Printed Parts (to be scaled in slicer with factor 3.0):

• HingePlate2Fingers.stl
• MinifigTorch.stl (2x)
• Plate_1x3.stl
• Plate_1x4.stl (2x)
• Plate_2x3.stl (4x)
• Plate_2x4.stl (3x)
• TileWithGrove.stl (2x)
• technic_axle_3.stl
• technic_axle_4.stl (2x)
• technic_axle_6.stl
• technic_axle_8.stl
• technic_axle_pin_no_friction.stl (2x)
• technic_brick_1x8_m4. stl (2x)
• technic_bush.stl (4x)
• technic_bush_toothed.stl (3x)
• technic_connector.stl (8x)
• technic_gear.stl
• technic_gear_rack.stl
• technic_wedge_belt_wheel.stl
• technic_wedge_belt_wheel_grip.stl

Optional printed parts:

• BodyTop.stl
• Helmet.stl
• Minifig_arm_left.stl
• Minifig_arm_left.stl (mirror in slicer)
• Minifig_body_bottom_plate_MultiStar4000.stl or BatteryHolderPlateStraps_NanoTech4200.stl
• Minifig_hand.stl (2x)
• Minifig_head.stl

Lego minifigure is based on: 

https://www.printables.com/model/24298-lego-jo

Recommended Materials:

• PLA (30% infill)
• ABS (30% infill): axles,pins,technic connector, bushes, rims
• Ninja Flex (10% infill): technic_wedge_belt_wheel_grip.stl, SlickTire_2830.stl, SlickTire_5010.stl

Hardware:

• bearing MR128ZZ (6x)
   

Electronics:

• 4 in 1 ESC (30A)
• Power distribution board
• Acceleration sensor: MPU 6050
• receiver (fly sky 3 channel FS-GR3E)
• servo: MG 946R
• neopixel Ws2812: (2x)
• for other electronics parts see drawing: "Schematics_ESP32.png"

Software Features:

• webservice which either connects to local network or creates its own accesspoint if local network cannot be reached
• webservice shows telemetrics, speedo and settings. Settings can be updated on the fly and are saved
• Acceleration sensor input is used to help steering in straight line
• In case of taking a turn, the inner wheels are slowed down to help steering around a corner
• LED string shows status (armed/disarmed) and indicates driving directions
   

Remarks:

• a custom name can be generated for BodyTop.stl using the BodyTop.scad source file
• print technic_wedge_belt_wheel_half.stl twice and glue parts together
• print technic_wedge_belt_wheel_grip_half.stl twice and glue parts together
• print technic_gear_half.stl twice and glue parts together

Alternatives for the glued “half” parts have been added that can be printed as a single piece:

• technic_gear_rounded.stl
• technic_wedge_belt_wheel_easy_printable.stl

Category: Vehicles