So you’re really looking for that [Norman Rockwell] Christmas and want to set up your train to encircle the Christmas tree this year. The problem is that all you’ve got is an old LEGO train set and not enough track for it. You can’t just buy some more, because the technology has changed; or can you?

[Chris] was dismayed to find that newer LEGO train sets have gone to battery operation rather than drawing power through metal tracks. The new tracks are plastic, and buying extra segments of the older version is cost prohibitive. He figured out a way to add power conductors to the new track pieces.

It turns out the design of the new tracks matches the old, except they’re all in plastic instead of having metal rails. He bought a plastic add-on set, then picked up some copper foil from the hobby store which is meant for stained-glass work. It’s adhesive backed, and after working out the best way to apply it, he coated the rails with the stuff. As you can see above, the new mates perfectly with the old, and keeps that locomotive chugging along.

If you’ve got copper foil left over after this hack, there’s tons of other uses for it. Perhaps building your own flex sensors is worth a try.