An Unnecessarily Complex Wire Spool Holder

Like many shop projects, this one started with a very simple problem:
loose wire everywhere.

Instead of building a basic passive holder, I decided to see how far I could push the idea while still keeping it practical. The result is a motorized, self-tensioning wire spool holder that automatically takes up slack across multiple spools using a single low-power motor.

Is this the simplest solution? Absolutely not.
Is it entertaining, functional, and oddly satisfying to watch? Very much yes.


The Idea

The goal was to create a wire holder where:

The key design choice was letting friction do most of the work.

All spools sit loosely on a shared rotating drum. The drum is driven by a small 5V DC motor. When the drum spins, spools with existing tension simply slip, while spools with slack rotate until the wire is lightly tensioned.

This allows the system to self-adjust continuously with very few moving parts.


How It Works

At the center of the assembly is a rotating drum driven through a gear reduction by a small DC motor.

Each wire passes through a notched guide at the front of the holder that triggers the motor when pressed. These notches provide enough grip to prevent the wire from retracting past the guide, while still allowing the user to pull wire out smoothly by hand.

Motorized… But Optional

While the design includes a powered retract function, the motor is not required.

If you want a manual version:

Because the motor torque is low, even the powered version benefits from occasional manual adjustment.


Hardware Required

All remaining parts are 3D printed. Files can be found on makerworld

Build Instructions

Despite the number of parts, assembly is straightforward.

1. Print the Parts

Print all components. Most parts do not require supports. The entire assembly mounts to a single base plate.


2. Install the Motor

Press the small drive gear onto the motor shaft.
Insert the motor into the left side of the base, the side


4. Install the Guides

Press the wire guides into the guide bases.
Attach the circular guide bases to the main base using M3 × 12mm screws. 

Attach self-adhesive copper tape to the guide arms and base guides. 

Solder wires to the copper tape for each guide.


5. Assemble the Drum

Press the large gear onto the drum.

Assemble each bearing carrier:

Repeat for both sides.


6. Final Assembly

Slide the wire spools onto the drum.
Insert the bearings into the drum ends.
Set the drum into the base and secure it with the bearing carrier top holders.

The drum should rotate freely with slight resistance.


7. Wiring & Setup

Wire the motor so it rotates in the retract direction.
Test the retract button.
Feed each wire through its corresponding guide.

When powered, the drum will rotate continuously and automatically manage slack.


Lessons Learned

This project could absolutely be simplified, but the fun was in exploring how much functionality could be squeezed out of a single motor and a handful of printed parts.


Final Thoughts

This wire holder is equal parts tool and mechanical experiment. It keeps wires organized, demonstrates a simple mechanical principle, and scratches the itch to overengineer something that didn’t strictly need it.

Happy Building!

- Over Complicated DIY