The Project Asylum


Coil Winder Electronics






The board layout was done by the author Robert Lang using free software from board manufacturer ExpressPCB. The pcb board file is available from Nuts & Volts magazine online.

Since I intended to make the board myself. I downloaded ExpressPCB, and installed it. Opened the board.pcb file, and printed the board layout to PDF Creator which allowed me to create a pdf file.

I opened the board layout pdf file in Paint Shop Pro, and modified the layout to shorten the jumper lengths because, I was making a single layer board that required jumpers, and increased the size of the through hole pads to make them more robust.

Using Paint Shop Pro the board layout was printed onto Techniks transfer material with my HP4L laser printer.
Automatic coil winder driver board layout printed on Techniks transfer material.
Board layout printed on Techniks transfer material.






A Steel square clamped down to the pcb material to use as a straight edge for scoring, and a piece of scrap wood is placed under the pcb to protect the work bench.



The board scoring process requires a bit of effort, and I generally go through a few utility knife blades in the process.

The circuit boards should be separated by aligning the score line of the board with the edge of a piece of wood or the edge of the work bench, and bending the board.

After separating the boards I file the board edge to smooth it and remove any copper burrs.
Scoring the automatic coil winder pcb board with a utility knife.
The board is scored on both sides before separating. Copper side is scored first so score lines are visible on other side when board is turned over.



Before transferring the toner to the circuit board. I use a scotch bright pad to clean and ruff up the copper surface. Than clean the board with an isopropyl alcohol dampened paper towel.

The toner is transfered to the board using a clothes iron with the temperature set just below the steam level.

I remove the transfer paper after the board has cooled.

I drill the corner mounting holes of the board being careful not to scratch the toner off the board.
Coil winder driver board circuit pattern transfered to circuit board.
Laser printer toner circuit pattern transfered onto pcb board using a clothes iron.


I agitate the etching solution by manually moving the board around in the solution to speed up the etching process, periodically removing it from the solution to check the progress.

The etching process typically takes less than 10 minutes to complete.

Board being etched with ferric chloride. I warm the echant with an aquarium to speed up the etching process.







When the etching process is finished, the board is submerged in two different containers of water, and then rinsed off under the faucet.


The dremel drill, and drill press work well for drilling component holes in circuit boards. I leave the toner on the board till I am finished drilling because it keeps the drill bit centered in the pad.

Also the toner keeps the copper from oxidizing so leave it on till your ready to install the components.

I remove the toner from the board with a lacquer thinner dampened paper towel.



I prefer to drill the circuit boards outdoors because of the fiberglass dust.



Underside of completed stepper motor driver board.


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

Completed stepper motor driver board.


 


The standard parallel port printer cable with a 36 pin centronics connector won't interface to the driver board.

A parallel port printer extension cable has the correct connectors to interface the parallel port of your computer to the male DB 25 connector on the stepper motor driver board.

I replaced the centronics connector on an existing parallel port printer cable with a female DB 25 connector to interface with the winder because I had the parts on hand.