Guitar Pick-up Coil Winder

This instructable was created in fulfillment of the project requirement of the Makecourse at the University of South Florida (www.makecourse.com)

This device was made with the intent of creating custom pickups for electric guitars. The vibration of the metal strings induces a current in the pickups, creating the signal that is then amplified to make the sound of the guitar.

The number of wraps or turns present in the coil is largely what determines it's sound and volume. Coils with fewer turns are often described as "cool", producing clear distorted sound, but may require a pre-amplifier to be built into the guitar. coils with more turns are "hotter", producing more volume but also more distortion.

As such, many users may want to create their own custom coils to achieve their desired sound. This device will allow the user to do just that. It was designed to wind pre-made bobbins, however the bobbin holder can be modified to accommodate anything for which the user can design and print.

Step 1: Gather Materials

As with most such projects, the materials listed below are a guideline rather than any hard and fast rule. Substitute where needed, and likely there are better choices that can be made for some after reviewing this guide.

You will need:

• Enclosure: PVC project box, 7.5" x 4.5" x 2.5"
• Motor: 12-volt motor with YC-52010 encoder (I recommend staying under 20 volts so that it can share power with the Arduino)
• Micro-controller: Arduino Uno or compatible
• 4x push incidental buttons
• 10K-ohm potentiometer
• 2x 5mm cube magnets
• plastic stand-offs for electronics
• 4x 4-40 x 1/2" fasteners with 8x nuts
• Motor controller
• 16x2 Serial LCD display
• 2x pen springs
• wire or male-male and male-female jumper wires
• DC switch
• DC male-female plug pair
• 12-volt DC power supply
• heat shrink tubing
• solder
• J.B. Weld

• non-slip rubber foot pads

Optional:

• solder-on pin sockets
• perf-board
• HC06 Bluetooth module
• testers enamel paint

Tools

• Hot glue gun
• #00 and #1 Phillips and flat screw drivers
• Drill and bits
• 3D printer
• soldering iron
• hot air station
• files
• deburring tool
• calipers
• multimeter

Step 2: Set Up Your Circuit

Begin by prototyping with a breadboard to save from embarrassing wiring mistakes. Buttons are set up for pull-down, into whatever digital pins are available. potentiometer into analog 0. For the I2C LCD screen, SDA is analog 4 and SCL is A5. the PWM out to the motor controller in in pin 9. The YC-52010 encoder hall effect sensor is on a hardware interrupt pin, digital 2. All of these components share common ground, and all but the buttons require and she 5 volts from the Arduino.

the arduino and motor controller will also require 12-v in and wall ground. I acquired a defunct 12v laptop charger, cut the end off and replaced male plug. DO THIS ON THE DC SIDE ONLY (after the transformer brick) AND BE SURE TO TEST THE PLUG FIRST TO CONFIRM POLARITY AND POWER DELIVERY! the outside shield should pretty much all be grounded unless the designer escaped the home for insane and incompetent circuit design, but it's good practice to check, and power delivery should always be confirmed.

On the female interface side, in the box, strip the the power jack ends. I interrupt the 12 volts in with a small DC switch, which then goes into Vin on the motor controller, and the ground wire goes straight into the ground slot. I use the motor controller terminals as the nodes for power to the Arduino and the motor. For powering the Arduino: I soldered on the exposed backside tabs of the power jack. the side is ground, and the center is Vin. Don't take my word for it, test it!

If soldering for a permanent connection, use heat shrink on all connections possible! It will make your product more durable, reliable, safer, professional-looking, and it will settle your gambling debts.

Step 3: Program

attached is the code, you can open it in the current Arduino IDE. The only additional library required is the , should be pre-installed.

Disclaimer: if Bluetooth control is what you're after, the code will need to be modified heavily or scrapped.

Step 4: Prepare Enclosure

Drill holes for the motor shaft at the top, potentiometer and buttons on the front, and USB-b port on the side. additional holes will be required for the board standoffs, which can be but in the base (now backside) of the box. I used a rotary tool to make the USB port a bit more square. You could also use a rotary tool cutting wheel to make the cutout for the LCD screen, or if using a very-well ventilated laser cutter (OFF-GASSES FROM BURNING PVC ARE ACUTELY POISONOUS). Similar techniques for the switch cutout.

J.B. Weld the female plug socket into its drill hole, be sure not to let epoxy into the socket.

Insert the LCD into the cutout, the use a drill bit or sharp file to each the location of the mounting holes. remove the screen, then drill the holes at the marked locations. do this as required with the other boards and any other additional components.

For lining up mounting holes that are only accessible from one side (i.e. the topside motor mount holes), use a piece of paper to make a stencil of the hole locations, mark them on the box, and drill.

Add non-slip rubber foot pads to the bottom side of the box.

Step 5: Install Circuit

I have a Ph.D. in rat's nests.

I relied heavily on hot glue to keep components in in place. While it may not sound professional, the Pros often stake cables and components with RTV adhesive. Hot glue sets faster, is easier to clean, and doesn't emit harmful vapors.

test your components before gluing, and avoid placing glue directly on conductor interfaces such as on male pins or inside female pin sockets, and this will insulate them.

Step 6: 3D Printing

no material preference. low infill, additional shells to allow sanding and filing.

press-fit magnets into slide.

remove any supports, rafts, or other additional materials. rough the flat face of the bobbin holder top, and the flat face of the main bobby. install the pen springs in the circular cutouts, then the slide, then apply J.B. weld to the flat faces of the top and main and clamp together over the slide, being careful not to apply too much to the interior so that the slide does not get glued.

after epoxy has hardened, use hot air to soften shaft opening on the main component and insert it onto the motor shaft.

Step 7: Final: Wind and Enjoy!

Thanks for reading! I encourage everyone attempting this build to do their best to improve it and share with others.