Homebrew Inductors
Making Your Own Miniductor Type Coils
This demonstration page shows how to make your own miniductor stock inductors.
For purposes of demonstration I used insulated wire because it shows in photos better than shiny copper. For your inductors you can use uninsulated copper. My choice of wire for real coils is #14 ground-wire purchased in the house wiring part of the local DIY store (Home Depot).
The pictures and captions at the right show my procedure and the result.
A section of ordinary PVC lawn sprinkler pipe was cut to length and slots were turned in it on my metal lathe. A wood turning lathe, or even a drill press could be used for this purpose. In this case the slots were spaced 1/8 inch apart. A lathe bit was custom made for cutting 1/16 inch wide slots, which were cut 1/2 the depth of pipe sidewall thickness.
Lines were made 1/4 inch apart around the turned PVC tube.
The section of turned PVC pipe was sliced lengthwise into approximately 1/8 inch wide strips. If doing this repeatedly, a jig would be built to make the process easier and more precise.
Not shown here, but wrapping the pipe form with two layers of paper makes the finished coil easier to remove from the pipe. You can draw guide-lines on the paper for placing the separator strips. A tie-wrap was used to secure several of the strips around a section of PVC pipe (plain rubber bands work just as well and are cheaper than tie-wraps).
Wire is wound around the PVC tube by placing it in the slots on your Spacer strips. It is possible to make small placement adjustment of the spacer strips around the pipe form after the windings are in place. Use a flat blade screwdriver and a small hammer to move the spacer strips by tapping on them between windings. After the winding is complete, glue is spread over the windings where they contact the spacers. I used regular PVC Pipe Cement like would be used to fasten pipe joints together. Spread on liberally, it fastens the wire quite securely to the separator strips.
After the glue has hardened, carefully pull the PVC tube form from inside your new homebrew inductor.
Trim the spacer ends, and touch-up any spots where glue did not adequately secure the wire to spacers.
The result is a homebrew miniductor type air-wound coil.