Finally got DCC now i need a lil help...

Discussion in 'DCC & Electronics' started by RonP, Sep 15, 2007.

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  1. railwaybob

    railwaybob Member

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    Some quick observations here.

    DCC is "alternating current". An analog (straight DC) motor will sing shriller than a cicada when placed on a DCC track. Solution - install a decoder in your locomotive. Otherwise you will be wasting a lot of time trying to determine if the problem is with your track, your DCC setup, or your locomotive.

    While the literature says you can run analog on DCC, it really doesn't work all that well. Installing a decoder can be as simple as cutting and soldering some wires, or having someone install the decoder for you.

    If DCC is running through the rails, the best way to check to see if you have voltage is to use the "coin test". Take a coin (quarter in the US, loonie in Canada) and press it across the rails. Your command station should "beep" and shut down. Remove the coin and your command station will "beep" and open up.

    Telephone wire is 24 AWG (American Wire Gauge) wire. If you are starting with a new layout, I don't recommend using 24 AWG wire for track feeds. I suggest using 22 AWG and even 20 AWG wire (the smaller the AWG number, the thicker the wire).

    The reason for using thicker wire throughout your layout is to protect your locos and trackwork when you derail or when you run a switch which causes a short. When a short occurs, the command station detects the extra surge of power and shuts down. If you use thin wire, when you short, the command station assumes that the extra demand for power is normal and keeps on pumping out the juice instead of shutting down. If the command station doesn't shut down when you run a turnout, for example, the juice continues pumping into the short.

    On an HO layout, this short can produce as much as 60 watts of heat at once (16 volts x 5 amps = 60 watts). To see what 60 watts is like, take a 60 watt light bulb and hold it in your hand (not recommended!) This can be more than enough to melt the plastic ties, weld some metal, or take a chunk of metal out of some rail or wheels.

    While you want to keep the runs of the thinner wires as short as possible, sometimes we can't do that. One trick is to run some 16 AWG wire from your 14 AWG track power buss to your track feed and solder the 16 AWG wire to the track feed.

    Try to keep mechanical connections to as few as possible. This is a source of power loss - if not now then certainly in the future as the wire and mechanical connections oxidize. The best form of wire connection is soldered wires. You may have to use a 100/140 watt soldering gun to solder 14 AWG wires rather than a 25/45 watt pencil soldering iron. If you look around, you can pick up a soldering gun for about $20 and a 25/45 watt pencil soldering iron for about $10.

    Just a few tips, tricks, and recommendations to help you along.

    Bob M.
  2. RonP

    RonP Member of the WMRC

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    Thank you bob i will use your advice.
  3. Spawn of Chaos

    Spawn of Chaos Member

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    I personally have the Zephyr, and I'm somewhat disappointed. I have run my DC locos on a Digitrax Zephyr layout before and they run at almost full speed. I wired up my own Zephyr to a simple OVAL and the DC locos only move at about half speed.

    I do understand that the idea of "model" railroading is not to go fast but to be realistic, but my test of performance of a transformer is to blaze all-out for a second with my fastest loco.

    Which, by the way, is an old old old Bowser...blaze and you ain't kidding!
  4. baldwinjl

    baldwinjl Member

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    If you know how the zero stretching mode used by DCC to run DC locos, you know that even when running in one direction the motor is being driven in the other direction at times. I don't think the performance of a DCC system driving a DC loco is at all relevant to the real performance of the DCC system. This mode is, and has always been, a bit of a kludge, and really isn't useful for much except to make sure a loco actually works before it is converted. Many DCC systems don't even support this mode any more.

    Jeff
  5. railwaybob

    railwaybob Member

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    Hi Spawn. The old Bowsers had the Pittman open frame motors. A very nice motor in the 1950s and 1960s for running full out and with some control, once it got over 50 scalle mph. But with the advent of can motors and the urge for more realistic running, got left behind.

    As I suggested above, in spite of what the manuals may say about running analog/DC on DCC, I don't recommend it. I suggest that you install a decoder into the loco. Once the decoder is installed, you can roar around your layout even faster than under analog.

    You may, however, have problems with that Pittman motor in the Bowser as the neutral return is through the frame of the loco. This will require substantial mods to the motor which might not be worthwhile. It can be done but it may not produce the results you are looking for.

    I've got two old Varney 4-6-0's and two 2-8-0's with real nice monkey motion on the rods and the valve gear. And there they sit as I haven't got the effort or inclination to change over the motors.

    Bob M.
  6. railwaybob

    railwaybob Member

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    Hey Jeff. Good point. This would be like shifting your car between forward and reverse while trying to reach 100 mph. I can't even do it at 1 mph when stuck in a snow bank let alone on a straight stretch of road. Which is one of the reasons why your analog loco hums like a cicada when placed on DCC track.

    Bob M.
  7. RonP

    RonP Member of the WMRC

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    Is speaker wire 18g stranded good enough for feeders ? I can't seam to find much else that size here. Also i am going to buy 4 decoders in the USA can someone suggest a good retailer for shipping to canada ? (the cross border sale is finally working for me (-= )
  8. baldwinjl

    baldwinjl Member

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    Eighteen gauge is actually pretty big for feeders, but if it looks ok it is fine. I've been using #20 doorbell wire on my N scale layout, I would have been happy at 22. as long as you keep the feeders to a foot or less it isn't a problem.

    Jeff
  9. ozzie

    ozzie New Member

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    Hi Ron,
    I am an Australian so that makes me a knuckle head to start off with, but i did have a problem with my layout which looks similar to your diagram.
    I started from the front of the layout board (say in your section A) and connected the "front" rail of each track to one bus and the rear track to the other.
    Problem was the "front" rail at the farthest track was on the inside rail (+) while all the others were on the outside track (-) result permanent short.
    might be worth a look.
  10. railwaybob

    railwaybob Member

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    18 AWG is a little heavy for track feeders. The practical max for track feeders is 20 or 22 AWG as any thicker wire (like 18 AWG) makes for complications in soldering the wire to the rails.

    Bob M.
  11. RonP

    RonP Member of the WMRC

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    Bob is the a problem with too much power here ? I am pro at tinning wires and soldering already tinned wires so that part is easy for me.
  12. RonP

    RonP Member of the WMRC

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    Let me just add that since adding the 18g feeders the trains still hum with no movement at all.
  13. baldwinjl

    baldwinjl Member

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    There is no problem with using #18 for feeders, just the way it may look and the difficulty in soldering it to the rails.

    Jeff
  14. baldwinjl

    baldwinjl Member

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    Just so I understand, this is a non-decoder locomotive, with channel 0 selected on the Zephyr. I have found that some non-decoder locos will do no more than hum, I'm guessing the mechanism is tight. In general, the address 0 mode is no more than a test mode, so there may be little more you can do without a decoder. If you don't have a short, there's not much more you can tell.

    Just thinking, if you have a DC voltmeter, you can try measuring the voltage on the rails. With address zero selected, the voltage should be near zero, and should increase (up or down), as you open the throttle.

    Also, select AC on the meter, and see what is on the tracks. That's not going to be an accurate reading, but still useful for debugging.

    Jeff
  15. RonP

    RonP Member of the WMRC

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    Decoder should arrive this week i cannot wait i hope i install it correctly. Is there any heat troubles with soldering them ? i intend to tin the wires and quickly attach them BTW i got the T1 fro TCS
  16. woodone

    woodone Member

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    Yes tin your wires, and use heat shrink to cover the joints.
    Go slow and make sure you have the right wire in its correct place. Again go slow! Just keep track of which wire goes where, and you will be just fine.:thumb:
  17. RonP

    RonP Member of the WMRC

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    Ok i installed the decoder and found it pretty easy, but ran into a few problems.

    1. i realized the back wheel set on my OLD f7 unit had the black wire fallen off the back wheel. So i re-attached with very little damage but with some damage.

    Next everything went fine I put the loco on the program track it read fine and loaded the unit address. Works great.

    this brings us to problem #2

    I get a short as soon as i put the unit on the main line.

    could this short come from my engine as the track isn't shorting out without the train on it. BTW this unit did run last year.

    TCS T1 decoder in a f7 bachman old unit
  18. RonP

    RonP Member of the WMRC

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    Ok i installed the decoder and found it pretty easy, but ran into a few problems.

    1. i realized the back wheel set on my OLD f7 unit had the black wire fallen off the back wheel. So i re-attached with very little damage but with some damage.

    Next everything went fine I put the loco on the program track it read fine and loaded the unit address. Works great.

    this brings us to problem #2

    I get a short as soon as i put the unit on the main line.

    could this short come from my engine as the track isn't shorting out without the train on it. BTW this unit did run last year.

    TCS T1 decoder in a f7 bachman old unit
  19. baldwinjl

    baldwinjl Member

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    Well, since there isn't a short until you add the loco.....it would be hard to conclude that the loco is not the cause of the short!

    So, we must think....you say it programs on the programming track, and you can read back the address. Does the light or motor do anything when you do that? Have you tried with the shell off? Does it short immediately or only when you try to turn on the light, add power, or any other thing?

    It strikes me that if you have a dead short the programming track would not be happy. So it must be sneaky. So, make sure the motor brushes are isolated from the frame, make sure the function outputs are not touching anything they shouldn't. Look for pinched wires.

    Jeff
  20. steamhead

    steamhead Active Member

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    How old is that Bachmann unit..?? Might it be that the motor need to be isolated from the frame..?? Check it out with a voltmeter by putting one lead on the metal motor casing, and touch a part of the metal frame with the other. If you get a reading, you'll need to isolate the motor.
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