Hey all, For some reason and I'm sure it's easy to solve my engine wants to go backwards when I have it set to go forwards. I have tried switching the track leads and today I took the decoder out of the engine and re-installed it. I also programmed it to a different address. I am using the Atlas Master System with DigiTrax DH 121 decoders. Any help would be greatly appreciated. Thank you Matt
You have two options here. First, you can add one digit to CV29. This tells the decoder to change its normal direction of travel. So, if CV29 is set to a hex value of 26 then changing it to 27 will tell it to run the other direction. The second option is to switch your Orange and Gray wires that go to the motor. This is the preferred method for me. Now some education. You have to forget about how things worked in DC. In DCC it doesn't matter if you switch the wire leads to the track (as you discovered). The decoder takes the power on the rails and converts it to the proper polarity for the locomotive. You can demonstrate this to yourself by running your engine forward. Now, pick up the locomotive and physically turn it around the other way. It will still run forwards. If you were using regular DC the engine would have run backwards. David
Thank you for the help. Now one other question. When I run the train(s) there are certain sections of track where the train either dramatically slows down or completely stops. I have re-laid the track and cleaned it. What are my other options? Thanks Matt
More power drops. the DC squarewave used by DCC systems is suseptable to voltage loss due to condustor (track) resistance. None of the materials used in track are particularly good conductors, and the furter you get from a drop, the less voltage at the railhead. Ideally for DCC you should have a drop every 3 feet or so, though this of course isin't always practacal.
I have to agree with cthippo. Don't rely on rail joiners for conducting power. I have a power feed soldered to every piece of rail. I have also modified all my turnouts to be "DCC Friendly" and as part of doing that every turnout has 5 power feeds. You might want to check out the website http://wiringfordcc.com.
