Sunday, April 17, 2016

Design of motor mount for brake


Initially, my plan was to use Acrylic and laser cutter to make a motor mount (last picture) . But after running the FEA, I found that safety factor of 0.88 for the design and material would not support the amount of forces that it must endure during the operation. I went ahead and make a simple mount ( L-shape mount) design using the A36 steel and 0.25 in thickness. Everything went very smoothly with the help of Alex helping me welding the plates together. the mount have safety factor of 5 and is very strong.

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Developing Code for Brake


This is the program that we have been working on to control the brake using the servo initially via an Arduino Uno.

   #include <Servo.h>
    const int trigPin = 9;
    const int echoPin = 10;
    Servo myservo;
    int pos = 0;
    // defines variables
    long duration;
    long distance;
    void setup() {
    pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
    pinMode(echoPin, INPUT); // Sets the echoPin as an Input
    Serial.begin(9600); // Starts the serial communication
    myservo.attach (8);

  }
    void loop() {
   
    // Clears the trigPin
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    // Sets the trigPin on HIGH state for 10 micro seconds
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
    // Reads the echoPin, returns the sound wave travel time in microseconds
    duration = pulseIn(echoPin, HIGH);
    // Calculating the distance
    distance= duration*0.034/2;
    // Prints the distance on the Serial Monitor
    Serial.print("Distance: ");
    Serial.println(distance);



  int am = 7;
  if (am < distance){

    for(pos = 0; pos < 180; pos += 1)  // goes from 0 degrees to 180 degrees
  {                                  // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
       delay(15);                    // waits 15ms for the servo to reach the position
  }
  }

  else {
  for(pos = 180; pos>=1; pos-=1)     // goes from 180 degrees to 0 degrees
  {                              
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
        delay(15);                    // waits 15ms for the servo to reach the position
  }
  }
    }

Disc Brake Mount Adapter for hub-motor 408 series

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We are having difficulty in obtaining a hub-motor with a mount for the disc brake. Therefore, I went ahead to create a solid work file of the disc brake mount adapter onto the hub-motor 408 series that we are getting. The only problem is to make this mount we need special tool and mold that can cast the mount correctly.
Inline image 2

Choosing location for Disc Brake


After many considerations, we finalize to install the disc brake next to the hub-motor as the previous year team did. The location is very convenient and directly applied to the main propulsion power. Another alternative is to install the disc brake on the outside of the red brake since it is spacious and directly applied brake to the large driving wheels. However, we need to consider making the  supporting arms that can hold the calipers firmly when applying brake.
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