A DCC ready locomotive has additional wiring making it easy to install DCC but does not contain a DCC decoder.  It will run on dc because it is a dc locomotive.

A locomotive equipped with DCC has a decoder in it.  Bachmann refers to such locomotives as "DCC on board."  Such a locomotive will run on dc if the decoder is set to allow it to do so.  Bachmann locomotives are shipped with this option turned on so that you can run them on dc right away.  Locomotives bought used or from other companies may have this option turned on or off when received.  If it is turned off, it can be turned on quite easily with an appropriate DCC command station.

While resistance (ohms) is one of the characteristics of resistors, you can, for a given application, use volts.  This is equivalent to saying "use resistor A if the source voltage is between 4 and 9 volts or use resistor B if the source voltage is between 10 abd 16 volts."  The idea is to dumb down the selection process by letting the supplier decide on the current range and voltage drop for his product.

For those who might be interested, some of the other characteristics of resistors include:
- power rating in watts
- tolernace in %
- thermal coefficient in %/degree
- voltage rating in volts.  This may be flashover voltage for high resistances working at high voltages or it may be the withstanding voltage of the resistor's coating.

Thanks, Tom.  Reason I ask is that I have been thinking about modifying a stock servo to work with DCC.  One way would be to convert the DCC decoder's output to pure dc and compare that to the dc output of the servo's potentiometer, then use the difference to drive the servo's motor.

As a steam traction engineer (which lets me operate our province's only operational steam locomotive) I am intrigued by your use of the steam cutoff to control speed.  Not a great idea with D-valves, but with piston valves, why not?   

Quote
- And as long as the live-steamer has insulated drive wheels ... it can "play nice"  with what the live-steam crowd refers to as the "sparkies"!  (The Bachmann locos, running under DCC control in my case):
Tom

Tom, have you ever thought of using DCC to control live steam?  Or ever heard of anyone trying it?  It strikes me that a DCC link would be cheaper than a radio link if you already have the DCC installed.  On the other hand, if you can afford an Accucraft Shay, maybe the price of the link doesn't much matter.

Just a thought.

Live steam is great if you like fussing around with a locomotive to make it run for a little while.  But, in general, live steamers are not great for pulling cars, let alone switching them in and out of industries.  For that, nothing beats electric power.

A typical lumber railroad might consist of a narrow gauge line from a logging camp deep in the woods to a saw mill somewhat more centrally located.  It might also have a train (narrow or standard gauge) running from the saw mill to where the lumber will be used, or this part of the operation might be implied rather than modelled.  In any event, switching is often involved at both the lumber camp and the saw mill.  Then there is driving the train between the two.  Depending on the space available, the distance from lumber camp to saw mill might be only a few feet or it could be many hundreds of feet.  How easy or how difficult it is to drive the train(s) depends on the twists, turn and gradients in the track.  A Heisler or other geared locomotive would be typical for this type of railroading.

If extending electrical power into the woods is a problem, then have the train do it for you.  Have it carry its own power in the form of batteries, either in the locomotive itself or in a follow car.  Rechargeable batteries can be recharged with a solar panel if no other source is available.  Radio control, in various forms, can be used to control the battery power, allowing you to change speed and direction, as well as operate a sound system if you like. 

The required voltage, measured at the motor terminals, is in the range of 0 to 12 volts with the actual voltage within that range depending on the speed of the train and other factors.  The voltage typically applied to the rails is in the range of 0 to 18 volts, with the extra voltage being lost to track resistance, rail-to-wheel resistance, wheel-to-power pickup resistance, etc.  Some other brands of trains use even higher maximum voltages, as high as 22 to 24 volts.

As far as current goes, the amount drawn by a particular train is the sum of all the current draws of the locomotive, lighted cars, and any other accessories.  The current draw of the locomotive depends on its speed, load, and accessories (lights, smoke, sound etc.)  The motor current normally never reaches the motor's stall (locked rotor) current as the locomotives wheels are designed to slip before the motor stalls at full voltage.  For a ten wheeler as in the Silverado set, a design current of 2 amps is adequate.  I was not able to find the other locomotive numbers using the Bachmann product search.  But a design current of 10 amps should be adequate to operate "at least 4 locomotives plus other things" in most cases.  Even though some of the locomotives may be multiple motor units, it would be unusual for all the trains to be drawing maximum current all at the same time.

Wanting to run "at least 4 locomotives plus other things" implies that you might like to run even more.  There are commercial power controllers available for up to 25 amps but at that level, you may find you weld the wheels to the rails in case of a derailment.  Click on the link below to see some of the supplies and controllers by Bridgewerks.

http://www.bridgewerks.com/index.html 

I have sent Larry my snail mail address and with his permission, will post any solutions we might come up with.

It is also possible to solder feeder wires to EZ track if you want to hide the wiring under the table.  Most of the methods used with regular track will work - soldering the wires to the outside base of the rails, soldering the wires to the bottoms of rail joiners, etc.

Quote from: Bojangle on May 12, 2007, 11:08:06 PM
...  Is the "coupling" you mentioned inductive or just harmonics? ...

Neither.  It is mechanical coupling through the motor wires which were pressed against the outsides of the motor and the insides of the plastic shell. 

As a kid, did you ever hold a sewing needle in your teeth and put the sharp end in a record** that was spinning on a turn table**?  The sounds you heard were mechancially coupled from the record to you teeth by the needle and from your teeth to your ears by the bones in your head.  Same idea here.

** For you youngsters out there, "records" were flat disks of vinyl, or earlier, shellac, that had wiggly grooves in them and "turn tables" were what spun them under a needle mounted in ...  Oh heck, just look up "phonograph" and "gramophone" on Google.

Quote from: Bojangle on May 12, 2007, 01:44:06 AM
... I suppose you could use a car battery and rheostat with proper current limiting (light bulb)...
Bo

That was actually used in the early days of H0 and is the reason that the original H0 trains ran on 6 volts dc, the same as car batteries of the day.  My first heavy duty throttles (heavy duty compared to what came with train sets) used power transistors and were powered by a battery charger.  And yes, DCC on board locomotives would run just fine on these controllers as long as the battery or battery charger is 12 volts.

Quote from: Bojangle on May 12, 2007, 12:32:02 AM
... does my loco have an internal rectifier  to change the AC to DC for the motor when using DCC controller? ...
Bojangle

Among a large number of other things, yes.

After commenting on Ten Wheeler's 4-4-0, I investigated one of my own locomotives which was noisy.  For details see:
http://www.bachmanntrains.com/home-usa/board/index.php/topic,1268.0.html

After Ten Wheeler's problem with a noisy 4-4-0 http://www.bachmanntrains.com/home-usa/board/index.php/topic,1234.0.html
I thought I would investigate the noise in my Bachmann DCC-on-board GP-40.  As received, it growled at all throttle settings above a dead stop.  I did not find the growling all that disturbing as it was quieter than the side winders and other coffee grinders of a couple of decades ago.  But some of my cohorts were nervous about this locomotive which, to them, sounded on the point of self destruction.

Removing the shell revealed a cast metal frame with the motor sandwiched between upper and lower sections of frame.  The motor was slightly loose in its mountings because the upper section of the frame was slightly warped.  But it was not so loose that it could rotate and touch the plastic shell.  It appeared, however, that it could rotate enough to trap the decoder motor wires between the motor and the plastic shell, possibly transmitting motor noise to the shell via the trapped wires.

One solution might have been to unsolder the wiring, remove the decoder, remove the top section of the frame, and then try to straighten the latter without breaking it.  But being lazy, I tried something easier first.  I relocated the motor wires so that they ran between the bottom of the motor and the bottom section of the frame in the area between the brush holders and the farther end of the motor.  The plastic end of the motor is narrower than its metal case, so there is more room to run the wires vertically up past the motor to the decoder printed circuit board.  When the body was snapped back on, the locomotive was quiet, to the point that my (slightly deaf) ears can no longer hear it run.  I hope my model railroading buddies will find it the same.

This is a classic case of a noise (in this case, motor noise originating from Bachmann's non-silent decoder) being coupled to and amplified by the plastic shell of the locomotive.  If you can break the coupling (in this case by moving a couple of wires) then the sound is no longer amplified by the shell. 

Google "quartering drivers"  There is lots of good information on the web.  If the locomotive has the motor geared to one axle and the rest are driven by side rods, the drivers MUST be quartered for the locomotive to run properly.  If the motor is geared to all the axles and the side rods have slots, then quartering can be approximate and the locomotive will still run well.

With most steam locomotives it is possible to remove the side rods from the wheels and then remove the axles c/w wheels from the locomotive.  This allows you to quarter the wheels one axle at a time on a quartering jig.  If you have some scraps of styrene plastic around, you can make your own quartering jig that will do the job.

Quote from: GN.2-6-8-0 on May 04, 2007, 11:18:26 PM
Hearing of all the problems associated with the Specturm line I would for one would be interested in seeing a poll as to how many of those buying these engines are having problem's and having to send them back to Bachmann for repair/replacement.....

A modeller buys a brand X locomotive and has problems with it.  He is likely to complain to the manufacturer and/or post on the manufacturer's forum.

Another modeller buys 20 brand X locomotives.  They are all fine.  He is very unlikely to complain to the manufacturer or post on the manufacturer's forum.  For example, over the years, I have bought about 3 dozen Bachmann Spectrum locomotives.  One suffered from a manufacturing defect.  It was easily repaired without returning it to Bachmann.  This is the first time I have ever mentioned this on any forum.

That just means this formum is very biased in terms of faulty locomotives vs. good locomotives.

The number of people who have problems and have to send a locomotive back for repair/replacement means nothing by itself.  You also have to know how many people are not having problems and do not have to send a locomotive back if you want the survey to mean anything.  I am sure Bachmann Industries knows what percentage of their locomotives are returned for repair/replacement, but don't hold your breath waiting for them to tell you.