Stepper Addon for Sergiu’s Cell Spool Winder

The GOAT Cell Spool Winder is so great that I decided to motorize it. I received permission from Mr. @Sergiu_Irimie to publish the files.

You don’t have to change anything, drill, or glue your existing spooler. You only need to reprint the receiving axle so the motor fits inside.

I split this project into 3 parts (shown in the picture from top to bottom):

Electronics disassembled

Power Unit

I didn’t want any more cables on my table, so I used an 18V DC battery as the power source. You can substitute this any way you like; there are many adapters for different batteries. I used this one, or you can just use a barrel jack. You can also power the Arduino and stepper independently, getting rid of the blue breadboard part shown in the picture (though that requires two cables).

Control Unit

I used an Arduino with a CNC shield and a custom soldered breadboard. Since I always respool the same length of filament, I don’t need a filament sensor. The Arduino acts as a timer, which stops the stepper after a defined time. You might want to adjust the time in the code based on your motor speed and spool filament length. The control unit is connected with two screws to the stepper bracket so the whole thing holds together.

Control unit

Breadboard wiring schematic

Stepper Bracket

This is a holder that snap-fits into the existing spooler. You can mount a standard Nema 17 stepper motor. The motor is removable, so you can change the receiving spool without needing to unscrew anything. You need to reprint the spooler axle so it fits the Nema motor adapter.

Stepper bracket with removable housing

Bill of Materials

• 5V Buck Converter

• Dupont Wires

• Nema 17 Stepper Motor

• Arduino CNC Shield

• A4988 Stepper Driver

• Arduino Uno REV3

• PCB Prototype Board

• 47 uF, 50V Aluminum Capacitor

• 4 x M2 and 13 x M3 screws

Happy printing!