Introduction: DIY VEX Record Player

About: Mechanical engineering student at the University of Michigan

This is a guide to the construction of a DIY VEX Record Player. Note that many of the following components have alternatives that can work better, these are just the materials that were available. This Record Player can play 33 1/3 and 45 rpm records.

What You Will Need

Total Cost : $36

Stylus $2 :

Arm Holder $4 :

Female to RCA Male $5 :

24 All Thread Rod 2$ :

2 packs of #10 24 Nuts $2 :

Sound Core Speaker $26 :

Vex Materials You Will Need :

7x Bars

4x Silver Bar

3x Touch Sensor

2x Base Plate

2x Spacers

1x Cortex

1x Battery

1x USB Cable

1x 393 Motor

1x Encoder

1x Gear

1x Axle

1x Motor Cable

X Screws & Nuts

Step 1: The Schematic

*The schematic is simply a point of reference, it is not to scale

Step 2: Attaching the Sensors

Components Needed For This Step : 1x Cortex 1x Base Plate 1x 393 Motor 1x Motor Cable 1x Encoder 4x Silver Bar 1x Bar x3 Touch Sensor x1 Axle

1) Place the base plate on the table facing up and attach cortex to the center of the base plate

2) 4 Spaces from the right side use the 4 silver bars to hold the bar above the base plate

3) Use the axle to align the encoder and 393 motor, then mount the 393 motor on the bar and the encoder on the base plate so then the motor is facing the base plate

4) Once correctly aligned fasten the 393 motor and encoder into place using the VEX screws and nuts

5) Attach all 3 touch sensors on the back of the base plate and the opposite side of the mounted motor and encoder

6) Connect all motors and sensors to their perspective ports on the cortex

Step 3: Building the Tonearm

Additional Components Needed For This Step : 1x Stylus 1x Tonearm Holder 1x 3.5mm Stereo Cable 2 Packs of #10 24 Nut

1) Drill a hole in the wheel of the tone arm holder wide enough for the #10 24 rod to fit through, this can be done by using a shim to hold the wheel in place

2) Wire the stylus to the leads on the 3.5mm stereo cable

3) Attach nuts to each side to hold the #10 24 rod in place

4) Attach the stylus to a nut at the end of the rod using hot glue

Here is a link to help with the wiring of the stylus :

Step 4: Mounting the Tone Arm

Additional Components Needed For This Step : 2x Spacers

1) Use the spacers to mount the tonearm approximately 3 inches from the edge of the cardboard circle, only two of the holes will line up with the top base plates, so the tonearm will have to be mounted using those holes

2) Adjust the tonearm accordingly using the #10 24 nuts

Step 5: Code

Additional Components Needed For This Step : 1x Battery 1x USB Cable

1) Connect the USB cable to the cortex and your computer

2) Connect the battery

3) Open the RobotC program

Here is an example code, yours may differ :

#pragma config(Sensor, dgtl1, Bump1, sensorTouch)

#pragma config(Sensor, dgtl2, Bump2, sensorTouch)

#pragma config(Sensor, dgtl3, Bump3, sensorTouch)

#pragma config(Sensor, dgtl4, Encoder, sensorQuadEncoder)

#pragma config(Sensor, dgtl6, Green, sensorLEDtoVCC)

#pragma config(Motor, port2, Motor, tmotorVex393_MC29, openLoop)

//*!!Code automatically generated by 'ROBOTC' configuration wizard !!*//

bool OnOFF = false;

task main()


while (1==1) // Forever

{ untilBump(Bump1); // Power

On OnOFF = true; turnLEDOn(Green); // On/Off indicator

while(OnOFF ==true)

{ if(SensorValue(Bump2)==1) // 33 & 1/3 rpm button

{ stopMotor (Motor); // Stops any previous code

startMotor (Motor, -16); // 33 & 1/3 rpm


else { }

if(SensorValue(Bump3)==1) //45 rpm button

{ stopMotor (Motor); // Stops any previous code
startMotor (Motor, -18);// 45 rpm


else { }

if (SensorValue(Bump1)==1) //Power Off


OnOFF=false; stopMotor (Motor); // Turns the motor off

turnLEDOff (Green); // On/Off indicator


else { } } } }

Plug in the speaker and enjoy!!!

Step 6: Demo