Tomix DE10 DCC Pt 2: Planning and Cutting

Read Part 1 of this article.

A preface: I’d hoped to have this wrapped up by now, but frying a headlamp and the decoder itself have proved insurmountable delays. I can at least say something about the first steps taken in this install.

Here’s where we left off: Pondering a tight fit! As it is, there are a number of places we could place the decoder. We could put it in place of one of the lightboards at the ends—but this doesn’t appeal to me. We could put it in the cab (requires cutting of some plastic), but it would be visible through the windows. Or we can remove a big chunk of frame right about here…

So that’s what I did. The first frame-half, I just used a medium-tooth hardware store file, one of the triangular ones for filing saw-teeth. The size was about right. I finished it with jewler’s files. For the second half, I used an X-Acto modeling saw to hack out large chunks first, which was faster but the results were a bit rougher. Not that anyone besides you and me will ever see these cuts anyway. I haven’t quite finished in this picture: In the end, I removed a good bit more material. Notice that I’ve made room for the decoder, and a little more room for the wires poking out.

Here is one half, cut, and one half, not cut, to show you how much material has been removed. I don’t know that this view is much clearer than the one above, but hey.

Here is the frame, taped together, and the decoder taped in place. The tape is just for this test-fit; I’ll use something more elegant later. You can see how we’re going to route the wires. The red and black power leads slip through the gap between the frames on the left, to be soldered to the brass strips that pick up power from the trucks. The orange and grey wires go along the top of the frame, through a channel I cut (see below), and into the motor compartment. The blue common has been spliced into two; one travels a short way to the left with the white wire, again through the gap between the frame halves (which I’ve widened just a bit to accommodate four wires). The other blue splice with the yellow travel through the channels to the other lightboard.

This top view shows the routing a little more clearly. The channels were really hard for me to cut with small hand tools: I recommend a rotary cutting disc for this task. The yellow and gray go down one channel; the blue and orange the other. You can also see the gaps between the frame halves I mentioned earlier. Note that neither the motor nor drive shaft guides are in place; there will be even more room between the frame halves when they are, as they are what hold the halves apart and insulate each half from the other.

The channels aren’t as deep as I would like (see comment on the limits of my hand tools above), but there is just a little space between the top of the frame and the plastic shell. So far, everything fits together wonderfully!

That’s all I’ve got for now. As you can see, the hard part is working up the nerve to cut at the frame, and the time (about 90 minutes) it takes to remove all that material. Not so bad, is it?

Next time: Cutting and soldering the wires (without frying anything, cross your fingers!), and wiring up the headlights (an interesting task in its own right).

Continue to Part 3 of 3 of this article.