Tender Trucks

Winding the Springs

I looked at how Kozo suggests to make the truck springs. He does mention you can buy them, but he kind of puts the builder on the spot when he says, "why not custom make them!" The process for making the springs starts off like a lot of other machining tasks. I had to make the tooling first.

So what I seem to be doing a lot of in this project is building the tools to build the project. That's OK with me because the reason I am building this project is to sharpen my machining and metal working skills. Parts is parts even if they don't go on the the project. Ha!

This is the first "tool" I had to make before I could start on the springs. You can see an awful lot of hard work went into this special device. That is exactly a 0.250" hole in that bar of aluminum..

I also had to make an mandrel to wind the spring on and a wire feed guide to feed the music wire onto the mandrel. They can be seen in the photo's that follow below.

0.039" music wire used for the springs is pretty tough stuff. I can cut it with the electricians pliers shown however a better method is to use the Dremel cut off disk. In this photo the wire has already been feed through feed guide bar and I am bending a 90 degree starter hook on the end.

Here the hook on the wire has been inserted into the mandrel and the wire feed guide has been brought up close to the mandrel.

These are two close wound turns to get things started. I must emphasize that springs are wound by hand with the power disconnected from the lathe.

This is with all the turns complete. There are quite a few extra close wound turns at the start but that is OK. I am really paying attention to the number of spaced turns made when the lath's half nuts were engaged. A few close wound turns are added at the end too. The Dremel cut off disk is about to do its job.

Both ends of the spring have been cut off with the Dremel disk. All I have to do from here is back off the live center and remove the spring.

It would be safer to put the spring in the PanaVice. Here I am about to trim off the extra close wound coils of the new spring. It is far easier to cut them off with the Dremel than to try and grind them all away.

This is how you make the ends flat and grind the spring down to exact height. Note the rusty looking water bowl very close by. I don't want to overheat the spring and loose its temper . Side grinding on a wheel should never be recommended. However the spring is a very light duty load against the wheel and not likely to damage it.

The caliper is kept close and constant check of the spring length is continuously being made. No, I can't stretch the spring out if I grind off too much. I was surprised at just how strong this spring actually is.

Here are all the special tools required and the eight springs made with them. I actually made several extra and a few trial learning springs. Springs are actually easy and fun to make. But making a lot of them would soon seem boring to me.

I have to admit, those are great looking trucks. I didn't show making the side bearings seen here for the first time on the top of the bolster. They are straightforward milling work

The springs really look good in there. Like I said earlier, they are quite stiff. I have all the parts numbered now (except the springs). Sure wish I had some track to set them on. I'm going to work on that. Then next...

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