How to Wind Your Own Springs

Written by David Eblen, photos by the author.

This is a journey through the mind and life of an inveterate scratch builder. There are a number of excuses for this activity including but not limited to ego, I can build it better than the factory guy’s, the not made at all problem, the I can build it cheaper notion, the rivet counter dude and the all inclusive we’re just nuts bunch. I’ll admit to a few of these but I’m not telling beyond the last one except to say I consider myself a modeler first and I love to improve my skills. My latest project is one of those “not made at all” problems that has gotten out of hand. It is, of course, the construction of a pair of GE U6b locomotives that I have shared with readers of the Shortline Modelers Lounge’s Facebook page at irregular intervals.

This brings us to the subject at hand. Springs. In this case the springs that fit in the trucks and would suspend the locomotive if it were the real thing. I am irritated by models that use non-scale springs that actually work like the real thing. That is, they really provide springing action to the truck. While that is a neat feature the springs look very wrong, too small a wire and way too much space between the windings. Since I was using an unsprung truck to begin with this was a no brainer. I had to find a spring of the proper size and wire diameter to fit in the spring well and between the spring planks in order for the whole thing to look right. I suppose I could have browsed through a catalog of the little devils to find something that would do the job, in fact I did, but it would have taken weeks to have them shipped and then test fitted, probably only to find they didn’t quite fit. You can see excuse number 1 creeping in here……

It's Not Just About Springs:

How did I get to this point in the first place? Not only am I a scratch builder however, I model in On30. Sometimes things get a little cockeyed in this strange subset of the model RR hobby. Like where do you draw the line at “Prototypical?” With only a few exceptions there weren’t any North American 30” gauge railroads and there were not any operating GE U6b’s. My Tonopah Southern does. To add to the problem the trucks I chose to use are Athearn units from their SD40 with the middle axle removed. This was done to make the wheelbase long enough to be a reasonable approximation of the U6b. It’s close but not spot on. What to do? Well, the 30” thing doesn’t bother me, so the minor discrepancy in the wheelbase doesn’t either. But the way the springs look does. Okay, I’m just nuts. Even if you are like me and are willing to accept some (?) variations in scale, research is probably the most important aspect of any scratch building project.

Although this truck's springs are not the same as the truck modeled here, this will give you an idea of the size of spring used on the prototype.

Having access to an artifact that you are modeling is the first order of priority. Lacking that, drawings, good accurate three view drawings are my first choice, backed up by as many close up photos as you can find. I leave you to your own devices to uncover sources. I use the internet a lot though finding drawings there is usually not a productive use of my time. You can’t build even a fairly accurate model without accurate information. If the project is worth the time and effort be prepared to spend some money on this part of the program.

There is another option also. At least in the weird world of On30 you can roll your own if you have some knowledge of what it is you intend to build. I spent 38 years as a locomotive engineer and am fairly familiar with how diesel locomotives function and so I am tinkering with the notion of actually designing an engine for the Tonopah Southern. It will probably be GE based but nothing that was ever actually built full size. This approach could be used on virtually anything model railroad wise but you must use restraint in order to end up with a viable model. It’s one of the reasons I really like On30. It allows creativity by its very nature.

Not Ready for Springs?
OK Let’s Build a Sideframe

Let’s get this out of the way. The side frames shown in the accompanying photos are non-functioning. They are just pretty baubles but they took a lot of work. I know the rivet counters out there are about to boil over and you’ve got to admit they have a point. The wheelbase is wrong, ergo the side frames are too long and if I didn’t tell you that the wheel sets are also a couple inches too small in diameter they’d never have known but now they are probably having convulsions. Even with all the research I had to make compromises but I still like the way they look.

The side frames are resin castings made from rubber molds from original masters I made from styrene. This is a subject for another article or maybe not as it has been covered by many better modelers than me. Suffice it to say that this technique is invaluable when you have items that need to be done in multiple. Trying to make four or eight identical side frames from scratch is virtually impossible unless you do them in brass. Brass blanks can be soldered together in a gang and filed to shape and then unsoldered, all pieces being as nearly identical as a casting if your filing or shaping technique is at all practiced. The resin technique is easier for me and guarantees perfectly uniform pieces.

The equalizers are also separate resin castings and the NBW’s on the bearing retainers are Grandt Line products added after they came out of the molds. As we progress you’ll note a definite “layering” system going on here. It is something I do with all my projects. Break the total thing down into smaller and smaller projects and then layer detail on top of the base units until it is completed. The downside of this is, of course, the opportunity to have a mistake ruin the project loom larger and larger as you move along. I learned a long time ago that there is no mistake that I cannot fix. If you use CA adhesives you can de-bond the parts. Plastic adhesives give you time to adjust positions and soldering allows removal of wrongly attached parts. If you really goof it up, throw it away. That was the hardest thing to learn but the most valuable. And if you are doing this by layering you aren’t going to loose too much if you do have throw it away. Which brings us to...

Engineering the Thing

Never thought it was going to get this complicated did you? Never fear it isn’t really. Engineering just means you have to think about what you’re going to do before you commit to hardware. Something as complicated as a model locomotive needs to be “designed” before you start cutting material. Even something as simple as a flatcar will get out of hand without some forethought. How does the draft gear fit the underframe? Are the bolsters the correct height for the trucks and couplers? Building things exactly to scale might prove difficult in a smaller scale if you are working off of a prototype drawing because it would be nearly impossible to find materials thin enough to replicate the actual structural members. Nothing would then fit.

With an engine you have to consider power trains, carbody attachment, lighting circuits, sound systems, cab interiors, etc. etc. Also under this heading is Cost Control. My U6’s are a good example of not paying attention to this element of engineering. The temptation to keep adding “goodies” is nigh on impossible to resist, at least for me, and it is driving the cost of these two engines out through the roof. It is something to keep in mind from the outset and to keep keeping in mind throughout the life of the project. Okay I’ll admit to the “I can build it cheaper excuse” and maybe I’m not the best guy to be giving this kind of advice. But it’s well intentioned.

At Last! It’s Spring Time!

Since the trucks are all built up now to the point that minus the paint and weathering only the gaping holes where the pesky springs are missing is staring me in the face. I didn’t want to waste a couple weeks and money shuffling them back and forth through the post office to find the “one”. Turns out making springs aren’t that difficult if you don’t have to make them on a production basis. It does require making a tool though. No howling out there, this is simple, doesn’t require welding or a lathe or plasma cutters.

For this project it turns out a piece of brass rod 1/8” in diameter makes perfect sized springs when you twist .024 brass wire around it. .024 equals approximately 1.1 inches in “O” scale which is pretty darned close to the size of an actual locomotive coil spring. We have to tweak the brass rod a bit as the pictures show but how simple can it get? File a flat across the end about 3/16 inch and drill a .025 hole through the flat. File a groove from the hole on the round side at the angle of the rise in the spring. How much? I don’t have a real good answer, I just guessed at it and it came out pretty good. Even if I had a good answer I don’t know how you would measure it or mark it on the rod. This angle should be fairly shallow though, you don’t want the spring to have a real steep angle of the coils. I used a small diamond coated rat tail file to cut this groove. The flat was filed there to make it easy to drill the hole only. It has no other purpose and you really should minimize its size.

To make a spring just push the .024 wire through the round side of the rod into the hole far enough to be able to bend it vertically to secure it. If you bend it any other way it will happily punch holes in your finger or thumb each time it passes around. Thread the wire into the groove and begin to wrap it around the rod tightly using your thumb to guide it. If you apply pressure to the wire it will wrap tightly into a spring. When you have enough coils wrap an extra coil on (The U6 required 6 coils) and cut the wire where it exits the hole. Be very careful or you may cut more than you should. Pull the coil off and trim the excess wire. I then use needle nose pliers to hold them and file the cut to a taper on both ends. It allows them to sit flat in the spring planks and finishes them off nicely. You’ll notice in the photos that my spring maker has a bend or handle on it. There is really not much force needed to make these springs but I like the feel of it and it gives a little better purchase so I don’t drop the thing.

If you have need for other size springs you’ll need to experiment with other size rods and wire sizes. As a practical matter I don’t know how small you could go. A change of material from brass might be in order if you got really small because it is pretty soft and might not tolerate the torque.

About the Author

David Eblen's picture

David Eblen

Retired SP locomotive engineer. Lifetime modeler. Former contributor to this pub


iandrewmartin's picture

Great article David. Thanks for sharing such a simple way to get springs made.

Yours sincerely
Andrew Martin
Owner of Andrew's Trains and the Hunter Valley Lines
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