Discussion in 'DCC & Electronics' started by csxengineer, Apr 21, 2006.

  1. csxengineer

    csxengineer Member

    I have a n scale 9' x 10' layout wired for DC with 9 different blocks. I have 2 powerpacks, and there are toggle switches for each block. 99% of the time I run layout by myself. I sold most of my engines, except for an Atlas MP-15 without decoder. I ordered 2 more for July, and now I am thinking about DCC. Questions:
    Should I replace the insulated railjoiners with regular ones, and leave one section as a "Program track"? I have 1 reverse loop, is this a nighmare for DCC? Should I replace all the blocks with 2 feeder wires? I want an all atlas system, is there a wireless controller, or can I unplug and plug it into other side of layout with a memory feature? can this all be done under $300.?
  2. 60103

    60103 Pooh Bah

    you don't have to remove any insulated rail joiners. Just disconnect the DC power packs and put the DCC controller where one of them was, and turn all the block toggles to that cab.
    A really cheap guy could even retain the old reverse loop wiring, but there is a little black box that does the job automatically. two wires to the main power and two to the reverse loop -- it flips itself when there's a short in the loop.
    If you can contain your engine purchases, your current wiring should work. The only problem is if you have light wires and you start running a dozen engines in the same block.
    You should have a setup/program track but it doesn't have to be on the layout. You could do it by wiring the program output from your controller to cab B, then select a block, switch it to cab B, controller to program, and go. (50 dcc enthusiasts will tell me why it can't be done.)
    Most DCC controllers have some sort of walkaround system. If not wireless, then usually there are sockets around the layout. You unplug the controller and everything continues on its merry way until you plug the controller in and give another command.
  3. pgandw

    pgandw Active Member

    I'll answer a couple of your questions; don't know enough specifics of the Atlas system to answer the rest.

    First of all - are your blocks insulated in both rails or just one?

    If insulated in both, you could remove your insulated rail joiners and block wiring, but why bother if the track is working fine? By leaving it, you can isolate DCC problems to a particular block. You can also replace one powerpack with your DCC system and leave the other one to give the opportunity to run either DCC or DC for a while. I recommend doing all blocks and all locos on the layout either DC or DCC, but not a combination at any given point in time.

    If you do not have both rails insulated, you can either insulate the second rail and do as I suggested in the previous paragraph, or remove all your insulated rail joiners for DCC. This leaves your layout as one large block/power district, except for the reversing loop which remains insulated in both rails in either DC or DCC.

    The easiest and most practical way to handle a reversing loop in DCC is with a device called an "auto-reverser". These rapidly sense the momentary short circuit when the wheels span the gap into or out of a reversing section, and change the polarity of the reversing section automatically to match. Note that changing the polarity of the rails does not change the direction of the loco - that is done by the decoder inside the loco. To prevent confusion caused by reverse section gaps in both rails being spanned at exactly the same moment, it is recommended to stagger the reversing section gaps by 1/8" or more in DCC.

    DCC problems with dirty track, voltage drops, short circuits, and the like have more visible consequences than with regular DC. You either lose control of the loco, or the layout shuts down (every block connected to a given DCC unit). I would recommend feeders for each rail in every one of your current blocks in DCC. A bus wire (at least 14 gauge in your case) should be run around the layout (but not tied together at the far end) for each rail. Feeders will attach to the appropriate bus wire unless you are keeping your block wiring. If you are keeping your block wiring, both rails must be controlled by the block switch. Your feeders would run from the block switches to the track.

    yours in control
  4. csxengineer

    csxengineer Member


    Tons of help! Yes, both rails are insulated for every block. 14 guage wire? I'm actually not sure what I'm using. should I use stranded or solid wire? I plan on maxing out at 5-6 engines all atlas mp-15s. I just read model railroader 12/2005 article on DCC. I narrowed it down to either:

    LENZ LZV 90

    any opinions? In the meantime, I'll try to figure out how thick my wire is. That auto reverse unit is soo long overdue in model railroading! I might use the old MRC DC power packs just for accessories such as street lights and LEDs on bridges, etc. I use regular turnouts, so one power pack can be used for them to avoid building lights flickering everytime I throw a switch.

  5. GeorgeHO

    GeorgeHO Member

    I would say that you never have to remove insulated joiners in HO for any reason. If you have your bus wires connected to each insulated block by feeder wires, then the two blocks are electrically equivalent, the same as if you have jumper wires connected across the insulated gaps. Because you have both gaps insulated, it doesn't sound like cab control, so for your bus wires you could get #14 or #16 stranded speaker wire, which is relatively cheap and available at almost all stores that sell anything electric or electronic. The speaker wire has two distinguishable wires (different color or a black ridge on one side)and you only have to remember which side goes to which track. Most people seem to use stranded extensively because it flexes, and reserve solid wire for feeders soldered to rail joiners for better contact, or to push through the layout base as a feeder, or inside a structure for lights.
  6. 60103

    60103 Pooh Bah

    My rule is use stranded when it has to be flexed; use solid for rail feeders; use whatever fits the rest of the time. I think stranded is more expensive than solid for a given size. Stranded is also slightly larger than solid for a given size.
    If the wire is solidly tacked down, solid will stay in place neatly.
    Stranded for wires to pickups in locos and for lights in removable rooves/bodies.
  7. csxengineer

    csxengineer Member

    First step

    I replaced all bus wires with 14 gauge stranded wire. I attached the feeders that were already solder to track to bus wires. I now have feeders every 3-4 ft. I only removed one set of plastic rail joiners at a trouble spot to get current from 2 different feeders to that are. My DC trains run smoother it seems. Next step, DCC.

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