Automatic Coil Winder

This is my build of the:
High Stepping Automatic Coil Winder
project that was featured in the June 2005 issue of Nuts & Volts magazine and authored by Robert Lang.

The idea behind the coil winder project was to create an automatic coil winder that the author could set up, walk away from, and return to a finished coil. He also intended it to be an introductory learning tool for his readers in precision object positioning and I happen to be one of his readers.

I have no affiliation with Nuts & Volts magazine or the author of the original article so if you are interested in reading the original article or building the High Stepping Automatic Coil Winder a print copy or digital version of the June 2005 issue of The Nuts & Volts magazine can be ordered from the Nuts & Volts website.

To run the winder you need a copy of the "CoilWinder" software program (you can download from the Nuts & Volts website) running on a pc with a parallel port.
A parallel port printer extension cable and a power supply to power the driver board and stepper motors.

To the right is a screen shot of the Coil Winder program. The white fields are filled in by the user and the green fields are the calculated results output by the program based on the user inputs.

For the wood parts of the coil winder I was able to use wood I had leftover from other projects.

The plywood I used for the sides and bottom of the winder have a 1/2 inch nominal thickness. The sides are cut to 8" X 8", and the bottom is 8" X 18". The side supports are 3/4" X 2 1/2" X 8", and the channels cut into the supports are 3/8" deep and the width of the plywood.

I had a difficult time understanding the placement of some of the coil winder components while referencing the original coil winder mechanical drawing, so I studied it and made my own drawing to locate the positions of the motors, and threaded and brass rods.

• Top Left: Cutting threads in an aluminum spacer to be used as the bearing surface for the threaded rod.
• Top Center: and Right: Drilling holes in winder components with dremel drill press.
• Bottom: 3/16" solid brass rods to be used for the various coil winder shafts. A 10-32 threaded steel rod used as the carriage lead screw and other miscellaneous parts.

The stepper motors the author used were surplus units from All Electronics and are no longer available.

Here is the information from the original stepper motor listing. I got this from The Wayback Machine.

New stepper motors are generally expensive to use for hobby projects.
I bought new old stock stepper motors through the Internet.

It can be difficult to find specifications for old stepper motors. I gathered as much information as I could, took a chance on these motors and I am quite satisfied with their performance.

The coil winder 28BB-H151-11 stepper motor wiring diagram & information.

The underside of the carriage base with polystyrene slide tube and threaded #10-32 hex nut fitted into channels and epoxied into place.

I formed the channels in the base with a miter saw, wood chisel and a round file.

Pilot holes were drilled into the top edge of the winder carriage before inserting the wire guides to prevent the wood from splitting.

The polystyrene material was purchased from a local hobby shop.

A 1.25 inch hole saw was used to cut the sheet material. The hole saw pilot bit cut the center hole just right for the .25 inch tubing.

I glued the spool together with gel super glue, but have since purchased a solvent to weld future spools together.

The foam cylinder in the photo was a sewing thread spool that I cut and sanded to use as a form to make the coil winder spools.

When I first started running the coil winder I noticed the stepper motors were randomly miss stepping.

After checking into the problem I discovered that my computer's parallel port could not properly drive the IRF510 mosfets specified in the original Nuts & Volts article.

Parallel printer ports use 5 volt logic so I replaced the mosfets with IRL540 logic level mosfets and it eliminated the random miss stepping.