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Assembly Guide

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diegoA-LR edited this page Apr 14, 2021 · 47 revisions

Before assembly

Power supply cord preparation

Please refer to this video for the necessary preparation of the power supply cord.

Killswitch installation on power supply

The killswitch should be installed before beginning the assembly. The wiring connections are as follows. killswitch_wiring_diagram
The killswitch should be installed firmly on the power supply, we used tie wraps as shown below. killswitch_installation

Protoboard soldering

The protoboard will be used to feed power to the servo motors and manage PWM and feeback wiring. The tracks on the board must be as follow:
schema_protoboard

Hip, Femur and Tibia servo motor calibration

The servo motors must be calibrated before being assembled to ensure optimal operating ranges. The code used to calibrate the servo motors is available in the Assembly Sub-Folder. The only thing to do is to plug the motor to be calibrated into its corresponding output in the PWM Servo Driver and change the index 0 in the code below to the same index.

void loop() {

  driver.writeMicroseconds(0,degToPulse(135,0));
  //delay(1000);
}

Parts needed

  • Appropriate electrical wires for the electrical connections
  • 1x Arduino Mega2560
  • 1x Power supply
  • 1x Step-down converter to 6.8V
  • 12x Servo motor
  • 1x Servo motor driver
  • 12x Servo motor horn

Please refer to the electrical schematic section in order to do the appropriate wiring between the power supply, drive, arduino, motors, step down and protoboard. The feedback wiring is not necessary for this section.

Hip servo motor calibration assembly steps

  • Connect 4 servos to the protoboard (feedback connections are not necessary)
  • Send a 135 degrees target to the servo motors
  • Insert the motor horns on the rotating shafts of the servo motors at a 90 degree angle
    • Two of each at opposite sides for right and left side legs (See image for reference) hip_calib

Femur servo motor calibration assembly steps

  • Connect 4 servos to the protoboard (feedback connections are not necessary)
  • Send a 135 degrees target to the servo motors
  • Insert the motor horns on the rotating shafts of the servo motors at a 90 degree angle
    • Two of each at opposite sides for right and left side legs (See image for reference) femur_calib

Tibia servo motor calibration assembly steps

  • Connect 4 servos to the protoboard (feedback connections are not necessary)
  • Send a 135 degrees target to the servo motors
  • Insert the motor horns on the rotating shafts of the servo motors at a 45 degree angle
    • Two of each at opposite sides for right and left side legs (See image for reference) tibia_calib

Leg Assembly

This section explains how to assemble the robot's legs. It is suggested to follow these instructions in the order they are shown to facilitate the assembly process. The steps to follow are the same for the right and left side legs.

Regroup all the 3D prints needed for the 4 legs. 3d_prints_layed_out

Femur

Parts needed

  • 1x Femur
  • 1x Servo motor (Mounted with the horn)
  • 1x Pivot cylinder
  • 2x M4x25mm socket head cap screw
  • 2x M4 nut

Assembly steps

  • Insert the servo motor into the Femur
  • Add 1 M4 screw on both extremities of the servo motor
  • Tighten both screws with the M4 nuts
  • Insert a pivot cylinder in the Femur

Femur_Installation

Hip

Parts needed

  • 1x Hip - servo motor part
  • 1x Hip - bearing part
  • 1x Servo motor (Mounted with the horn)
  • 1x Bearing
  • 2x M2x12mm socket head cap screw
  • 2x M3x30mm socket head cap screw
  • 2x M3 nut
  • 2x M4x20mm socket head cap screw
  • 2x M4 nut
  • 1x Pivot cylinder

Assembly steps

  • Tighten the servo horn of the previously assembled motor with the 2 M2 screws

  • Insert the motor horn into the hip (servo motor part) assembled_into_hip
    Here is a close-up without the Femur to show this assembly step. close-up

  • Insert a servo motor into the hip

  • Add 1 M4 screw on both extremities of the servo motor

  • Tighten both screws with the M4 nuts hip_insertion

  • Insert a pivot cylinder in the hip - servo motor part pivot_insertion

  • Add the bearing into the hip - bearing part

  • Insert the bearing into the pivot cylinder located on the Femur
    18

  • Align both hip parts and add both M3 screws

  • Tighten both screws with the M3 nuts
    16

Tibia

Parts needed

  • 1x Tibia - main part
  • 1x Tibia - motor support part
  • 1x foot end
  • 1x Knee - bearing support part
  • 1x Knee - servo horn support part
  • 1x Servo motor (Mounted with the horn)
  • 1x Bearing
  • 2x M2x8mm socket head cap screw
  • 1x M3x15mm screw
  • 1x M3 flat washer
  • 1x M4x25mm socket head cap screw
  • 3x M4x30mm socket head cap screw
  • 4x M4 nut
  • 1x Pivot cylinder

Assembly steps

  • Insert the servo motor into the tibia main part

  • Add the tibia - bearing part

    • Make sure that the wires pass through the top side of the part( see image for reference)
      7

  • Add 1 M4 screw on both extremities of the servo motor

  • Tighten both screws with the M4 nuts
    6

  • Insert the servo motor horn into the knee - servo horn part

  • Tighten the servo horn with the 2 M2 screws
    8
    9

  • Insert the bearing into the tibia - bearing part

  • Insert the pivot cylinder into the bearing

  • Insert the pivot cylinder into the knee - bearing part 10 11

  • Take the assembled femur-hip and align the femur holes with the knee holes

  • Add 2 M4 screws into the knee parts and the femur

  • Tighten both screws with the M4 nuts

  • Pass the cables from the tibia motor into the slots located on the femur 13 12

  • Align the foot end with the tibia main part

  • Insert the M3 flat washer in the foot's hole

  • Tighten with the M3 screw

  • Add glue for stronger assembly 173755440_168444565133063_8672354733532960238_n 172453466_306322581105535_5289298508284695738_n

Body fixtures

Parts needed

  • 1x Servo horn bloc
  • 1x Bearing bloc
  • 1x Bearing
  • 2x M2x20mm socket head cap screw

Assembly steps

  • Take the assembled tibia-femur-hip and insert the servo horn bloc onto the servo horn of the hip's servo motor
  • Tighten the servo horn with the 2 M2 screws Here is a view of the bloc assembled on the servo motor without the leg assembled
    15
  • Insert the bearing into the bearing bloc
  • Insert the bearing onto the hip's pivot cylinder 17

Repeat all the previous steps (leg assembly) for each leg

Body Assembly

This section explains how to assemble the robot's body. It is suggested to follow these instructions in the order they are shown to facilitate the assembly process. It is also recommended to prepare the protoboard and add all the necessary wires before installing it into the body.

Assembling the wooden body

Parts needed

  • 1x Top body part
  • 1x Bottom body part
  • 2x Longitudinal beam
  • 2x Access panel
  • 2x Access panel hinge
  • 2x Access panel lock
  • 4x C-clamp
  • 20x M3x8mm wood screw
  • Wood glue

Assembly steps

  • Add glue to the top body part along both of the longitudinal holes

  • Insert one longitudinal beam into the top body part longitudinal holes

    • Use hammer to ease insertion of the beam

  • Insert the second longitudinal beam into the top body part longitudinal holes

    • Use hammer to ease insertion of the beam

  • Add glue to the bottom body part along both of the longitudinal holes

  • Insert the longitudinal beams into the bottom body part longitudinal holes

    • Use hammer to ease insertion of the beams

  • Hold the parts together with C-clamps for as long as recommended by the glue manufacturer (Make sure all the parts are well aligned before tightening)

    (refer to the picture below for acces pannels installation)

  • Once the glue dried, install the panel hinges on the acces pannels with the wood screws

  • Drill 1 wood screw per pannel as a door knob

  • Fix the pannel hinges onto the body

  • Fix the pannel locks onto the body access pannels

Fixing the legs onto the body

Parts needed

  • 2x left leg assembled
  • 2x right leg assembled
  • 1x body assembled
  • 16x M5x50mm Socket Head
  • 16x M5 nuts

Assembly steps

Repeat the following steps for each leg

  • Insert the servo horn bloc and the bearing bloc attached to the hip into onto the body (between the top and bottom part). Make sure that the servo horn bloc is located to the front of the body
  • Fix the blocs with the M5x50mm socket head and tighten with the M5 nuts leg-body assembly 1 eg-body assembly 2

Adding the electrical components

Parts needed

  • 1x Arduino
  • 1x Raspberry Pi
  • 1x Servo motor driver
  • 1x Protoboard
  • 1x Step-down converter 5V
  • 1x Step-down converter 6.8V
  • 12x M3x8mm screw

Assembly steps

Refer to CAD for electrical component locations.
Refer to the electrical schematic section for the electrical connections between the components
Inside the body :

  • Install both step-downs
  • Connect the PWM wires of the protoboard to the servo motor driver
  • Install the protoboard and the servo motor driver
  • Install the Arduino
  • Make the necessary connections for the Arduino (feedback, drive, ground)
  • Connect the 6.8V step-down + and - to the power supply
  • Connect the motor wirings to the appropriate cable from the protoboard
  • Install the Raspberry Pi and connect it to the 5V step-down with the USB-C cable
  • Connect the Arduino to the Raspberry Pi with a USB cable

S4H2021-QuadrUS

Home
Bill of Materials (BOM)
Robot Anatomy
Servo Motor Feedback Signal
Assembly Tools Needed
Electrical schematic
Assembly Guide
Calibration Guide
Using the GUI

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