One of the operable signals that we have on our museum line is an Erie Railroad US&S type S semaphore. The head of our signal department is looking for a spring (see photo) for this signal as this one is "nearly shot" as he describes it. Anyone that might be able to help, please contact me.

Thanks!


Les Beckman (Hoosier Valley Railroad Museum/North Judson, Indiana)

It might be worth contacting associated Spring, and seeing if they would be willing to have their prototype shop wind a few.

In a previous life I found them to be very responsive to requests for prototypes. You're not an industry that will buy thousands of course, but they might be willing to help. Worst case, they could quote on a short run.

http://www.asraymond.com/products.html

Steve Hunter

It looks like it might be a stock torsion spring. Maybe McMaster-Carr or Century Spring can help.

When looking for the spring you need the wire size (measured with a micrometer) number of turns and length of the arm. Outside diameter of the coil helps as well. You may have to bend the hook in the end yourself to match the original. Material is more then likely music wire.

You also need the direction of wind (right- or left-hand), and the angle between the legs when spring is relaxed.

Looks likes McMaster-Carr has a pretty good selection of "typical" torsion springs;

http://www.mcmaster.com/#torsion-springs/=11n54ce

And they do offer a custom spring winding service if you can't find something stock that will work.

So, I would remove the spring from the mechanism and measure it carefully (wire diameter, coil ID and/or OD, number of turns, leftie or righty, length of the legs, and the relaxed angle between the legs).

I bet you can find something pretty close in that list. You may have to buy a couple since they are often sold in packages of 6 for the smaller ones.

For these small orders the shipping can exceed the cost of the parts. I usually keep a list of "stuff" to order from McMaster-Carr and once it gets up to about $50 I'll place an order. The shipping for $5 worth of parts or $50 worth of parts is about the same. So some special nuts, bolts, taps, etc, I'll just wait until I have a big enough list to make the shipping worthwhile. But McMaster-Carr will gladly sell you one item for $2 if that's all you need.

McMaster-Carr is a great source of parts for "older" and "unusual" stuff. I purchased a single 1-1/2" LEFT hand threaded hex nut from them a while back, were else could you find that ??

Good luck, Kevin.

PS: I do not work for McMaster-Carr, just a satisified customer.

Just to file in the back of your mind. Next time you are looking for spring rigging/brake pins and bushing, check the local John Deere service center. They have an assortment of pins/bushings in nominal inch sizes and lengths for their tractors/front end loaders. At least that was the case a few years ago.

You can make your own. Buy music wire of the same diameter, set your lathe to the similar number of threads per inch, and wind on a mandrel about 10 percent smaller than the desired internal diameter.

Most spring companies offer free engineering samples try Allied, Associated, Lee, and Century Spring. These are the guys making them for McMaster and others. Some of them even have design tools on their websites to help you match the spring you need with stock items.

More then likely the original was a standard off the shelf spring at one time as production levels of this kind of equipment were not high enough to warrant custom springs. Often when I design equipment that needs a spring I will change my designs to match a standard mass produced spring as custom springs are cost prohibitive in my numbers.