The last few days, in between feeding and changing our 2 week old baby, I've been trying to make some progress with track laying on the layout. I've not got far - and not just because of the baby!
What has held me up is something I hadn't even given much thought to before - the electrical connections to the turnout. I've been trying to follow the instructions in one of the Scalefour Digest sheets (the one about turnout construction using C&L components). It says to cut small lengths of copper-clad strip and glue them to the 3 timbers beneath the crossing-V and also to the two timbers at the heels of the switches - between the switch and stock rails. Then it says to drill holes through the copper-clad, timbers and baseboard, pass a wire through each and solder it so it's flush to the top of the copper-clad; then lay the rails as normal and solder where they pass over the copper-clad strips to make the electrical connection.
Now, I've had all sorts of problems trying to follow this method:
Initially I glued the copper-clad strips to the timbers using 5-minute epoxy, but didn't account for the fact that the '5 minute' refers to when it's touch-dry, not when it's stuck solid, so as soon as I started drilling with the mini-drill, the copper-clad simply came loose.
Next I tried with super-glue and left it over night. However, when I tried to solder the dropper wires into the holes, the heat from the soldering iron melted the glue! Even disregarding this, using normal 188 wire solder and flux I ended up with a huge blob of solder on top of each piece of copper-clad, but no bond between the copper-clad and the wire (maybe because I had the top of the wire flush with the top of the copper-clad so the heat wasn't getting to it properly).
So I switched back to epoxy and left it to dry a bit longer. In the meantime I experimented with soldering wire into drilled copper-clad and found that solder paint is the best option to avoid the big blob. Also, it makes more sense to leave a bit of the wire sticking out above the top of the copper-clad while soldering, then snip and file flat. But once it's been filed flat there is so little solder that the join is pretty weak and I don't like the thought of a weak joint buried beneath the ballast etc.
Having put it aside for a while I've been thinking about it and started to wonder exactly why the copper-clad strips need to have dropper wires soldered to them anyway. Surely they are simply there to make the electrical connection between the rails. The power feed can be supplied direct to the rail at the toe of the turnout can't it?
Having put it aside for a while I've been thinking about it and started to wonder exactly why the copper-clad strips need to have dropper wires soldered to them anyway. Surely they are simply there to make the electrical connection between the rails. The power feed can be supplied direct to the rail at the toe of the turnout can't it?
ReplyDeleteNo reason at all. You just need electrical conductivity. But, you do need electrical conductivity between the crossing nose and wing rails (normal turnout gapping). I found such a fault last week on a friend's layout; the wing rail made occaisional contact with the crossing nose, so power to the crossing area was intermittant, and small locos would sometimes stall.
The copperclad seems to be there for a mix of cosmetic and wiring convinience. Evidently "where you are now" makes installing copper clad far from convinient !