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New Person Questions

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  • Member since
    February 2008
  • 18 posts
New Person Questions
Posted by Seldom Seen on Saturday, February 2, 2008 5:44 PM

The last MR my wife and I made was about eighteen years ago.  We want to make a new one in '50s D&RGW N scale and wish to limit it to a point-to-point setup with maybe a turnaround at each end.  DCC is a completely new concept for us but it looks a lot easier to wire than the old DC block system.  We still have most of the components left over from the previous layout.  I have some basic questions:

1. Can we use the internal switches in our old Tortoise motors to reverse track polarity in a reversing section if we used a seperate DC p/s and a toggle switch?  This would mean we wouldn't have to spend extra cash on accessory decoders.  Since our MR will focus on low speed industrial switching rather than fast freights, throwing a toggle switch for a turnout is not a problem.

2. Can we convert (hard wire) our old "late '80s/early '90s" locomotives to accept decoders?  We have two BevBel F7As, an Arnold switcher (S2?), an Atlas RS-3, a Bachmann F9 and Bachmann 2-6-2.  These engines are basically in new condition with almost no run time. 

3. We are leaning toward the NCE Power Cab for a starter system.  I doubt we'll have a need to run more than two locomotives.  The track plan is to have an L-shape with both halves of the "L" measuring about 2'x12'.  Would we need a seperate booster for more distant track feeders or will the internal booster handle the whole job? 

I sure hope this makes sense.  I've been studying DCC on the internet and Don Fiehmann's book: "The DCC Guide" all day an it's all beginning to run together.Shock [:O]

 Best, SS

  • Member since
    September 2006
  • 565 posts
Posted by Bapou on Saturday, February 2, 2008 5:49 PM

The old engines will take a decoder fine, if it is possible to isolate the motor from the frame. Go with the NCE!

 Please no DCC system is best wars, we all have our opinions.

Go NJT, NJ Transit, New Jersey Transit. Whatever you call it its good. See my pictures and videos here: http://s239.photobucket.com/albums/ff20/Bapouthetrainman/
  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Saturday, February 2, 2008 6:14 PM

1.  With DCC, wiring will be almost identical to DC block control wiring except that you do not need so many toggle switches to turn blocks on and off.  Yes, you can use the Tortoise switch motor's internal contacts to reverse the DCC signal phase on your reverse loop, but you must stop the train within the loop while you do so.  Note that with DCC, you are not reversing the track polarity, you are reversing the phase of the DCC command signal's square wave.  A Volt-Ohm-Milliammeter (VOM) will not detect a phase reversal, so you must be very careful with your wiring through the Tortoise contacts.  Personally, I would not trust the Tortoise contacts for this use, because I have found some of them to be unreliable.

2.  Practically every engine can be converted to DCC as long as there is room inside for a decoder and you can totally isolate the motor's brushes from all contact with the frame.  A problem you're most likely to encounter with old motors is their current draw, which might exceed the decoder's rating.  So you need to perform a current draw test on your locomotives before converting them.  Some might run so poorly that they're not worth the cost of conversion.  Use a VOM to test the current draw and motor brush isolation before deciding whether to attempt a decoder installation.  If a locomotive does not run well on DC, it will not run well on DCC.  When I began converting my locomotives, several of them wound up sitting in a museum static display area on the layout because they ran too poorly to justify the cost of a decoder.

3.  The NCE PowerCab is a very good starter system, and it can be expanded and upgraded as the need arises.

  • Member since
    January 2002
  • From: Portland, OR
  • 3,119 posts
Posted by jfugate on Saturday, February 2, 2008 7:22 PM

I too like the NCE PowerCab system a lot, but do be aware if you expand the PowerCab beyond its 1.7 amp initial capacity and then later decide to move to a full blown ProCab, you will not be able to use some of the expansion hardware.

That's the one fly in the ointment on starting with a PowerCab -- if you expand the PowerCab with a Smart Booster and then later want to move up to the ProCab, your Smart Booster is essentially a boat anchor. As long as you know you will never want a ProCab, then this issue won't matter.

The Digitrax Zephyr does have a slightly better upgrade path than the PowerCab in this regard, although the stationary powerpack form factor is not as handy for walkaround layout designs. While the PowerCab is a tethered walkaround, the dogbone is also the command station, so you cannot unplug it. If you make your own 25 foot coiled tether from a phone handset cable, that may be all the mobility you need, however.

I'm also hearing good initial reports about the MRC Prodigy Advanced Squared if you are a smaller layout owner -- and the wireless upgrade seems to be well done. I hope to get more info on the latest MRC offerings. Maybe they've finally done DCC right?

Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon

  • Member since
    February 2008
  • 18 posts
Posted by Seldom Seen on Sunday, February 3, 2008 10:22 PM

Great stuff! Thanks all.  I forgot to mention that my very first layout was back in the late '50s in Lionel with my older brother.  How's that for experiencing the whole spectrum of MRing?

Best, SS

  • Member since
    September 2007
  • 178 posts
Posted by chicochip on Wednesday, February 6, 2008 8:02 PM

SS,

Same for me....Lionel in the basement circa 1958-1959. My brother was about 10 years older. I, have not taken a hiatus from the hobby, though. I guess that means I've been at this for about 50 years! OUCH!

The Other Chip

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Thursday, February 7, 2008 6:35 AM

I'll try your first question, the one about the Tortoise.  It sounds like your plan is to use the accessory outputs of the Tortoise as a reverser.  In theory, that should work, but I would be concerned about the "switching latency" involved.  That's the time it will take between when one set of contacts opens and the other set closes.  My guess is that you'll find this is a problem, since the slow motion of the Tortoise probably takes some time to activate that circuit.  (I don't have any Tortoises myself, so they may have spring-loaded this to get a faster flip time, once it goes.)

Turnouts don't have to be operated on DCC control.  In fact, I would say that only a small minority of DCC users do this.  I run my turnouts the old fashioned way, with toggle switches on a control panel.

Many DCC users have found that DCC Auto-Reverser units for reversing sections are a big advantage.  You can basically ignore the circuitry once it's installed.  The ones from Tony's Trains (www.tonystrains.com) in particular are robust and very, very fast, since the switching circuitry is all solid state.  The problem with a slow switching time (back to "latency" again) is that the DCC circuit in the engine may shut down and restart if the power is off for too long.  The engine will stop and then re-accelerate up to its previous speed if this happens, and you really don't want that.

It takes an iron man to play with a toy iron horse. 

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