Breadboard Bits - Springmaking
Anyhow, in the process of constructing the bezel for my frequency counter, I found myself needing some particularly unusual springs. Where, thought I, am I going to come up with springs at 1AM?
Now, many years ago, I got involved with jewellery making. Specifically, I got involved with wire jewellery. This skill has helped me tremendously even since then, and I never shy away from an opportunity to pick up a spool of wire and make something.
There are two tricks to making springs. The first is successfully winding the spring itself. The second is the heat treatment to make it springy (spring aging).
The first task was easy enough. I wanted a spring with a fairly wide pitch, which is not easily accommodated with simple hand winding. Hand winding allows extension springs to be relatively easily made, but not compression springs. So I needed a winding jig. I grabbed some craft store "flower wire", and a spool of "silver colored craft wire". I bent the flower wire into two interlocking shapes, the mandrel and the feeder. I fed some wire into it and started cranking. The end result is a relatively well-spaced spring.
The one problem with this design is that the "stop" at the end had to be cut off when the spring was complete. I should have put the stop by the key. Oh well, live and learn.
The second task, I tossed the whole spring winder onto an electric range element and dialed it up to 2/3rds power, then waited 5 or 6 minutes. Then slowly turned it down, and waited for the spring to cool. It seems to have worked quite well. This spring has a really high constant. It's difficult to compress, and it acts quite springy even when trying to bend it. I'm sure my thermal curve was less than ideal, but it seems to have worked.
