4WD or 6WD Shock-absorbing Off-road Vehicle

The 4WD off-road shock absorber adopts a 2mm one-piece stamped and formed bottom plate, and the surface is aluminum sprayed. It adopts 4 high-speed motors with original speed of 17000rpm and a 1:34 gearbox to obtain greater torque. The shock absorption part uses 4 adjustable metal shock absorbers to improve the load capacity of the trolley. The 4-wheel drive makes the trolley better The passing capacity of the road surface improves the off-road performance of the car, especially on the road surface with complex terrain.

Equipped with a 4-DOF robotic arm, the steering gear includes a 25kg high-torque dual-axis steering gear and MG996 steering gear. The maximum 5V5A power supply module provides sufficient power for the robot arm, and the dual 2*23A motor drive module provides sufficient power source for the car; Using BlueBird UNO (compatible with Arduino UNO), you can use it after downloading the program; the in-line PS2 interface with rich buttons can achieve more ways to play, and the in-line model airplane remote control interface can greatly increase the remote control range, according to your own Choose the right type for your needs.

6WD:https://www.instructables.com/6WD-Shock-Absorption-Robot/

1. Arduino UNO
2. Motor Driven(MD04)
3. RC remote control
4. 2s Li-po
5. Expansion Board(4DOF Robotic Arm)
6. Frame

The assembly part is divided into the frame, the robotic arm, the main control, and the frame is installed with matching metal parts, the thickness is 2mm, the black surface is processed, and the robotic arm uses the same material; the servo part wiring needs to be installed Order to avoid confusion in the control, the servo is a standard 180°, and there is no mechanical limit structure, so the angle needs to be calibrated before installation. Here, the unified calibration is 90°. The main control part is fixed inside the frame, with 1mm metal shielding around it, and holes are reserved.

The mechanical arm is fixed on the upper part of the frame and fixed on one side, which is convenient for the grasping and control of the mechanical arm. The grasping diameter is 50mm and the weight is less than 200g. It is recommended to use a value less than this range.

1. Fixing bracket

The big U-shaped bracket is on the bottom and the small U-shaped bracket is on the top. Pay attention to the direction of the opening, and install the remaining brackets according to this method.

• M3 * 10mm Screws x 8
• M3 Locknuts x 8

2. U-shaped bracket and motor bracket

The bearing is installed inside the bracket, the screw is inside, and the nut is outside. (The picture above is only for style description)

• M3 * 10mm Screws x 8
• M3 Locknuts x 8

Align the motor fixing hole with the bracket and fix it with screws.

The red and black wires at the back of the motor are fixed on the side of the fixed position of the main board (for easy wiring), and the motors on both sides are connected with wires, and the wires from the motors are connected to the output ports of the motor drive board. Connect the motors on the same side (left and right on the same side), do not stagger the connection of the motors.

• M3 flat head screw x 8

Fix the metal shock absorber to the bracket, connect the upper bracket and the motor bracket, the shock absorber can adjust the spring strength.

• M2.5 * 16mm screw x 4 (upper)
• M2.5 * 14mm screw x 4 (lower)
• M2.5 lock nut x 8

Note: When adjusting the spring strength, pull the spring downwards, adjust the upper backing ring, and rotate it to adjust the height.

The wheels are fixed to the coupling and tightened with M4 screws.

Fix 6 copper pillars to the chassis, and fix the side brackets in the corresponding holes (installation later), pay attention to the location of the download port, so that it is easy to modify and download the program after installing the finished product.

Side brackets (not included in the base chassis) pay attention to the front and rear and left and right positions, and keep the signs pointing in the same direction. Pay attention to the protruding part of the side bracket when covering the upper bottom plate, and adjust it slightly if it is out of alignment.

Note: The bottom wheel drive part has been roughly installed. Because the upper bottom plate needs to fix the robot arm, the upper and lower bottom plates need to be fixed later. We fixed the robot arm, the line sequence is overall and beautiful, and the upper and lower bottom plates are fixed together. You can ignore this prompt if you don't have a robotic arm.

The installation of the robotic arm needs to pay attention to the position of the angle of the steering gear. Because the steering gear has an angular range, it can only run the default angle (0-180°), and the angle is fixed. It is not possible to set a certain point as the starting point ( Except for different styles of servos).

The angle is installed in accordance with the following settings. Before installation, use the controller to set the steering gear angle to 90° to facilitate the installation of the robot arm. The following takes one degree of freedom as an example, and the other degrees of freedom are the same. (The angle of the claw part can be modified according to the control requirements).

The side bracket is fixed to the upper chassis, using screws to fix 3 holes, the left side is M2.5 screws (red frame), and the right side is a single M3 screw.

The steering gear is fixed to the bracket and fixed with self-tapping screws, 2 on each side, aligned with the corresponding holes; the side of the steering gear with the output gear is fixed on the rear side of the frame, and the auxiliary shaft faces itself.

The steering gear angle is planned according to 3 directions 0°, 90°, 180°, so the angle reset state is very important, and the default 90° is the reset value. (Following rudder discs are installed according to this, the main shaft has teeth, and the positive direction is adjusted)

Fix the long U brackets back-to-back together, fix them with screws and nuts. Fix one end of the fixed bracket to the motor shaft, and fix both sides to the steering wheel with self-tapping screws.

The angle of the steering gear is up to 90° to ensure that the lever arm has a sufficient operating range to the left and right.

The fixing bracket is combined with the flange rod, and the short specification screws are used. The long screws will push the flange rod out.

Use an L-shaped wrench to loosen or tighten the silver machine screws on the side of the flange rod to adjust the parallelism.

The steering gear is fixed to the hand claw, and the steering gear output shaft corresponds to the inner side. After the steering gear is fixed, fix the steering wheel to the steering gear output shaft. The angle of the steering wheel is shown in the figure.

When the steering wheel is fixed, make sure that the steering gear angle has been reset to the 90 degree position, which will be calibrated for the subsequent control. If the position is not correct, if the given angle exceeds the mechanical limit, the steering gear will be blocked and damaged.

Use black PCB spacers (not clear to check the list) to support the motherboard to prevent the pins on the bottom of the motherboard from touching the metal chassis and cause short circuits. Use screws and nuts to fix and tighten.

The MD04 motor drive pins are aligned with the UNO motherboard header slot at the bottom and inserted, so there is no need for cumbersome pin wiring; the power supply is input by VIN, GND, here the voltage range is 6-12v, and the 3 motors on one side are connected to MA+, MA-, The 3 motors on the other side are connected to MB+ and MB-. The motor drive can also be connected to the expansion board as the lead out of the remaining ports, which is convenient for connecting modules such as sensors. Ensure that the power supply is stable when in use.

When the power supply is driven by the motor to drive the VIN pin input, make sure the voltage range is 6-12V, because the Arduino motherboard and the motor work in this range.

• The bottom 3 motors in the figure are a group, the wiring is connected from the 2 side to the middle part, and the middle motor pins are welded with 2 wires to the MA+ and MA- of the motor drive board. Wrong connection will affect the control effect.
• The upper 3 motors in the picture are a group, the wiring is connected from the 2 side to the middle part, and the middle motor pins are welded with 2 wires to the MB+ and MB- of the motor drive board. Wrong connection will affect the control effect.

Note:

The modules are all exposed chips and pins. The motor drive power input part (VIN, GND) conflicts with the ICSP pin header of the bottom motherboard. If you need to use it, please cut off the motherboard ICSP port header, or solder the wire to the driver board. VIN and GND ports, and ensure that the solder on the back does not contact the pins.

Power management: The module uses a regulated power output to provide a stable power supply for the steering gear, and it is connected to the 5V port at the bottom to avoid affecting the stability of the motherboard. The power supply can continuously output 3.5A current, and instantaneous 5A current, which can provide enough power for modules with high power consumption.

Wireless receiver port: The aircraft model is a 3*6P header, suitable for receivers with more than 6 channels, just align and insert it directly.

Servo interface: 5 steering gear ports, connected to D3, D9, D10, D11, D12 of arduino UNO, 3P curved pin, the top part is the signal pin, the middle is +5V, and the bottom is GND.