Wind-O-Matic 5000 (WOM5000) is a device that makes measuring out wire for antennas for 20m band effortless.

Steps:

Attach antenna wire to your spool tube
Mount spool tube on the WOM5000
Press the "Activate" button
Watch as the stepper motor rotates to collect just the right length of wire for 20m (199.2")



            

There are several sets of things you need:

List of circuit components from Adafruit
The 3D print files for the WOM5000 Platform and Drum
The firmware to run the RPi Pico

You probably already have some of the components you need.


File downloads below.

            

There are two 3D parts -- the platform and the drum.

The platform -- all sections necessary to hold everything together neatly.


The drum -- press fit to the stepper, used to hold your antenna roll in place during winding.

            

Once you have the parts, and the 3D files printed, assemble by:

Press-fit (hard) the Drum to the stepper motor shaft
Insert the stepper motor into the 4-corner retention area
Flash the RPi Pico with firmware
Solder headers on the RPi Pico and Stepper Controller
Put RPi Pico and Stepper Controller on a mini breadboard on the Platform
Use jumper wires to wire up the RPi Pico and Stepper Controller (see below)
Wire in 5v regulator (see below)
Wire in stepper (see below)
Wire in power button (not shown below)
Wire in Activate button (not shown below)

Soldering is required for some connections!


Details of how to wire in the buttons are left to the user.


The buttons are not meant to be mounted with screw backing, use a dab of hot glue or superglue to hold in place.


Here is the wiring diagram:


Here is the fully assembled front view.


Here is the fully assembled top view.