I have parallel tracks laid, and have just realized that it would really be nice if trains went in opposite direcxtions on them: e.g., an East-West track and a West-East track.
This has interesting wiring implications, particularly with DCC, and I wonder if any of you have experience doing this…?
Ron in New Hampshire
Ron, I think you may have missed one of the points of DCC is that it makes this type of wiring very simple. Lets say you have a single DCC power booster, it will have an A rail and a B rail connection to the track (digtrax uses this terminology, other brands may use a different term, but one track output goes to each track) If you are using a power bus with feeders for the track, then one output goes to each powerbus line. It is very important that the feeders from the A powerbus get to the correct track side, so you make a decison if it is the left rail or the right rail and stick to it. As you go around the layout it is essential to stay with this convention otherwise you will wire in a dead short and nothing will work.
So in simple terms, as long as you keep your A rail and B rail convention as you wire these, no problem.
The question is, how do the trains get from one direction to the other? Is your layout a continuous loop, so that a train will head East-West turn in a loop somewhere and head back West-East on the opposite track? If this is the case. If you are looking East-West and the A rail is on the left, then looking frome West to East on the other track it will still be on the left as you are now facing in the oposite direction.
If you mean wire the track opposite of each other, I have done that by mistake a few times and it always results is an electrical short. It’s easy to mix up what feed wire is connected to which rail while under the layout.
One way of preventing connecting the drop feeders to the wrong bus wire is to use a Piezo buzzer as a tester. All you need is a [url=“http://www.allelectronics.com/cgi-bin/item/PE-34/115/1.19"#34;_DIAMETER_X_0.29"#34;_ENCASED_PIEZO_.html”]Piezoelectric Buzzer[/url] a 9 volt battery and [url="http://www.allelectronics.com/cgi-bin/item/BST-71/970/9V_BATTERY_SNAP,_T-TYPE,_7"#34;_LEADS_.html"]snap[/url], a couple feet of small gauge stranded wire and 2 alligator clips.
One battery lead is connected to the buzzer and the other battery lead is connected to a clip (a piece of wire can be soldered on to extend the battery lead).
The other clip is connected to a pice of wire going to the other terminal of the buzzer. When the clips touch, the buzzer should sound.
Clip one lead to each rail, and if you cross wires, the buzzer will sound.
For straight DC control, I have but one comment - “direction switch”.
For DCC, the train will go forward reguardless, so all this would be doing is setting up electrical problems and extra complexity on crossovers (like needing an automatic reversing unit).
Wait a minute. Are you suggesting that both trains are on a single controller?
This is the same reason I chose to go with DCC. I had thought about having two DC controllers, one for each main, and then insulating the cross-overs, but that would have been a lot of hassle for a less-than-ideal solution. With DCC, you can run any train in any direction on any track, but per what simonl966 says, make sure all of your A feeders connect to your A bus, and your B feeders to your B bus; otherwise you’ll have a permanent short. Best of luck!
Ron, my layout LOOKs like double track mainline but it really is just parallel track with reverse loops at each end. That way, I can switch, run around or do whatever at any of the stations along the way, and have continuous running East-West and West - East. It works fine. And with DCC, it’s a sinch to wire in the reversing loops.
Paul
Ron, do you actually have DCC, or is it something you’re planning for the future? If you are running DC right now, then you probably need to isolate the two parallel tracks with insulators. It’s still straightforward to re-wire them with DCC, without removing the insulators, but if you’re starting with DCC now you can save yourself some effort.
If you have a large layout and these are really separate loops, you may want to isolate the tracks anyway. This will allow you to put in separate “power districts” to divide your power load and provide circuit-breaker protection to sections of your layout.
For a small-to-medium DCC layout, though, as long as you avoid reverse loops you can just wire everything together. Remember, with DCC you run the trains, not the track.