TOC, you are quite right, all Wally asked was whether he could run his g-scale locomotives with decoders installed by Bachmann with the Bachman DCC system.  There were numerous things Wally did not ask, including anything about Bachmann decoders, shiny wheels, worn wheels, current draw, grades, tractive effort, and on and on.

If we accept your premise that Bachmann installs two kinds of decoders, "Tsunami Decoders" in large scale and "Bachmann Decoders" in smaller scales, then traindude 109's first answer was smack on, and should have ended this thread.  One five amp booster is barely enough to run a two motor plus two single motor locomotives at the same time, and then only if there are no steep grades involved.  He might have added "and no long trains are involved either."  He even went so far as to tell Wally he would need non-Bachmann decoders in his other LS locmotives.   At no point did he suggest that the Tsunami decoder in the 3 truck Shay was inadequate to drive a Shay with as many cars as it can handle up the steepest grade it could handle.

Interestingly enough, this is supported by your own data, TOC, where you say a Shay can blow a 4 amp breaker on a 4% grade.  Blowing a 4 amp breaker means the locomotive is averaging more than 4 amps.  That would not leave enough power to also run two single motor locomotives with a 5 amp booster.  To run the Shay and run the pair of single motored units, you would have to limit that Shay to lesser grades, just as traindude 109 claimed.   (I suspect Stan missed that "and" and thought traindude 109 was claiming the Shay could not handle the grade.  Traindude 109 was talking about the booster.)

Traindude 109 also suggested someone else would provided more information but it seems that all the "experts" have been doing is fighting!  So let me say to Wally - there are lots of other decoder manufacturers out there that make decoders suitable for large scale at prices ranging from less than $50 to about $110.  Generally a 3 amp decoder is enough for a single motor locomotive and a 5 amp for a dual motor job.  Four motor locomotives generally have lower power motors and so can also be run on 5 amp decoders, although this is marginal.  Decoders up to 8 amps exist but the choices are limited, and of course price goes up with amps.  To run more locomotives, you can generally add more boosters.  I say "generally" because there are boosters that are limited to one per layout.  The MRC Power Station 8 was such a booster.  Whether the Bachmann 5 amp booster is also limited to one per layout, I do not know - I have not yet had the chance to take one to pieces.   

Who's decoder?  If it came from the factory with a decoder installed, then the decoder is a "Bachmann decoder," no matter who made it.  I buy a Ford and it comes with a "Ford transmission," no matter who made it.  No use muddying the waters by getting overly technical on nomenclature.

If it came with a factory installed decoder, why would you want to change it out for another decoder?  Lots of reasons, perhaps, in terms of features.  But certainly not because it was inadequate to handle the motor load.  And only an idiot would install a 1 amp decoder in a 3 amp locomotive, no matter what the scale.  The same guy who would try to save gas by installing a lawn mower engine in a dump truck.

The beauty of DCC is that it does not matter who made the decoder, it will work with the Bachmann DCC E-Z digital command control system.  Not like radio control where my LocoLink equipped locomotive sits there dead on the rails as I madly push the buttons on my Train Engineer throttle.  I suspect it is this non-interchangability of radio control components that makes the compatability of DCC decoders so hard to accept for radio control proponents.

For sizing decoders, we need to know motor draw.  But as far as that motor draw is concerned, it matters not a whit what shape the wheels are in, what the grade is, or how many cars it is pulling - the important current rating is the one with the motor stalled, not moving at all, not turning, not producing any motion, not ... well, you get the idea.

Dave, thanks for asking.  How much current you can draw depends on track voltage and how big a heat sink you attach the LM317 to.  I use one of these circuits per car with no heat sink and it has no problem lighting all four lights.  You could use it power a second car but might need a small heat sink, say a 1" x 2" piece of 1/16" aluminum.  I have used a similar circuit with a 3" x3" heat sink to deliver an amp out at 18 volts in, but the heat sink ran too hot to put right next to plastic.  Based on that, you could probably use one circuit to power the lights in about 10 cars if you mounted the LM317 on a piece of 1/16" aluminum the size of the bottom of the car.  Whew!  Long answer to a short question.

If the rails are clean enough that the lights flicker only occasionally without the circuit, or with the circuit but with the battery turned off (I see I forgot the on/off switch in series with the battery) then there is very little draw from the battery.  With little draw, NiMH and NiCd batteries would probably go dead by self discharge before you ran them down in service.  I use alkalines because of their long shelf life.  Both AAs and 9 volt batteries work equally well.  In normal operation, you might have to change the 9 volt batteries once a year.  With the AAs, it will likely take several years to run them down.

To look a little deeper into batteries and battery life, let me say that I run on aluminum track, both indoors and out.  I can do this only because I oil the rails - one drop per rail every 100 feet.  This means I don't have very much flicker to start with - I would guess the batteries are supplying power to the lights only 1-2% of the time.  You probably have different track and may or may not oil it, but just the fact that you are running DCC means you are probably keeping your track pretty clean.  So I think you too would have very good battery life with this circuit and could stick with 9 volt rectangular batteries.  The built in battery compartment and on/off switch are convenient to use, and this leaves space in the washroom for the circuit.

Yes.  It runs the length of the locomotive and is the most prominent feature in the photo below:



The red arrow points to the Digitrax DZ123 decoder (also red.)

Dropping voltage with a resistor can be a risky business, and this is one of the cases where it is.  How much voltage a resistor drops is proportional to the current through it.  So if you install a resistor sized to drop from say 18 volts down to 9 volts for 4 lamps, it will not drop enough voltage for the remaining three lamps if one burns out.  If the voltage drop decreases, then the voltage on the lamps increases.  With lamp life varying as the 13 power of the voltage, a small rise in voltage shortens lamp life radically.  Within hours, a second lamp will burn out.  Then, within minutes, a third lamp, and seconds later the last lamp will burn out.

For that reason, the circuit I use contains a voltage regulator.  It is shown below



In this circuit, a bridge rectifier rectifies the DCC track voltage to dc.  As the DCC waveform is rectangular, virtually no filtering is required.  A small capacitor (.1 to 1 microfarad) is connected across the bridge rectifier to keep the voltage regulator from oscillating.  Too large a capacitor here can overload the command station or booster on start up if many lighted passenger cars are used.  The regulator is an LM317 adjustable voltage, integrated circuit regulator.  With the resistors shown, it can be adjusted from about 7 to 12 volts output.  The output of the regulator and the output of a 9 volt battery are both connected to the lamp(s) through diodes.  With this arrangement, whichever source (regulator or battery) has the highest voltage will be the one that supplies power to the lamp(s).  I usually adjust the regulator output to be about .1 volt higher than the output of a fresh new battery.  This is easy to do it you connect a voltmeter from the output of the regulator to the positive terminal of the battery.  Then you are measuring the difference in voltage between the two sources.  If you connect the plus lead of the voltmeter to the regulator output and the negative lead to the battery +, the variable resistor can be adjusted until the meter reads +.1 volt (NOT -.1 volt.)  By keeping the regulator and battery voltages similar, the lights do not noticably change brightness when switching over between sources.

I usually build this cuircuit on a piece of perforated circuit board and hide it either in the washroom or under a seat, depending on whether I install AA batteries or a rectangular 9 volt battery. 

Alan, see if this helps (click on the link.)

http://members.shaw.ca/the.trainman/pesky-pickups/




For msowsun, a photo of the axle wiper pickups.  For the rest, a teaser from the above article.

I just checked, and mine says "Made in Austria" too.  That makes it Roco.  (Mehano is Solvanian.)

Rich, I recently put Digitrax DZ123 decoders in a couple of Atlas/Roco S-2 locomotives, which are the same as the Atlas/Roco S-1.  If yours says ROCO on the bottom of the frame, then it is the Roco mechanism.  I have photos of the installation including the all important isolation of the bottom brush holder.   

John's suggestion is also a good one.  The decoders are very similar except the ATL-S4 has-stop-on-dc; the DZ-123 has transponding.  The price of the DZ-123 is half that of the ATL-S4, I assume because the DZ-123 is a general purpose decoder used in many locomotives in Z, N, H0 and other scales while the ATL-S4 has a very limited market.

Whichever way you choose to go, be sure that the directions include isolating the bottom brush holder of the motor.  If this step is neglected, the locomotive will still operate well, at least until the locomotive derails and destroys the decoder.

I used to use glue - Goo, hot glue, rubber cement, you name it.  I still do for non-ferrous screws.  But the magnet on the screwdiver shaft is much cleaner when you can use it - no residue to clean up after installing the screw.

I think I'll let someone who lives in the US answer that.

The run time of battery lighting can be greatly extended.  Using LED's instead of incandescent bulbs can cut power consumption by 80%.  So instead of 1 hour on a 9volt alkaline, you get 5 hours.  With rechargeable NiMH 9 volts batteries, the time goes up to around 12 hours.  Make that a lithium polymer battery and it goes up to about 25 hours.  Still not long enough?  Put two AA cells in the battery box and four more in a battery holder in the washroom.  Make those high capacity NiMH cells for a life approaching 150 hours.

I run DCC which gives a constant voltage, but the pickup can flicker.  So I regulate the rectified DCC and regulate it down to about 9.5 volts.  Then with a pair of diodes, I let the lights choose either this regulated track voltage or 9 volts from a battery pack of 6 AA alkaline cells.  After 5 years running with this setup, I have yet to change the batteries.  And this is with the original bulbs, not with LEDs.   I have never measured it, but I suspect the lights run 99% of the time on track power and 1% on battery.  The only drawback is that it only works with DCC.   

The Digitrax DZ123 is slightly smaller and half the price.  The ratings are the same and the features are similar.

This is a more difficult install than most.  If you have another locomotive that you also intend to convert to DCC, then you might want to do it first.  You also need good soldering skills for this install.  If you have any trouble soldering, then take some time and practice before starting on this one.

Having said that, these locomotives are superb runners and well worth the effort.

Figure out exactly where the new turnout will go, then cut a hole to fit the switch machine.  When you go to mount the switch machine under the turnout, slip a piece of .010 styrene in between the two.  You will have to make five holes in the styrene, four for the mounting tabs, one for the pin.  Then install your turnout on the railroad, holding it in place by your favourite method.  Finally, bend the styrene to conform to your under track road bed (cork, or whatever.)  A little heat often helps here.  I sometimes use a soldering iron, running it back and forther where I want the bend, but without ever touching the styrene.  With the styrene sheet covering up the hole, it will be easy to completely hide the  switch machine with ballast.  If you do not plan to ballast, paint the top side of the styrene to match your roadbed before installing it.

John C, was that Hornby Dublo by chance 3 rail?  Our group recently had a set donated to us.  It is in pristine conditon, not even a spec of rust on the tin plate track, and it is hard to tell that the trains have ever been played with.  We presently have it on static display at our local museum.

I was surprised to see how much of this 00-3 rail is being bought and sold on eBay.

There are a great variety of teeny weeny screws and that means a wide assortment of screw drivers.  Rather than buy a magnetic one of each, I use a small rare earth magnet take I stick to one side of the screwdriver shaft.  Even several inches up the shaft from the tip it gives a good strong grip at the tip for both removing and installing screws.

When I drop a screw, I stick the same magnet in a plastic bag and go fishing.  By the time the outside of the bag is covered with iron filings, drill swarf, iron saw dust, and hopefully the screw, it is easy to get it all off the magnet by turnig the bag inside out and removing the magnet.  Without the bag, cleaning off a rare earth magnet is about impossible.

If the small magnet doesn't work, I break out the big one.  Just a little larger than a quarter, you need special tools to separate two of these babies if they ever get together.  Again the plastic bag trick.  These rare earth magnets will even pick up "non-magnetic" stainless steel nuts and machine screws.  Sorry to say, with brass and nylon screws, it is down on the hands and knees with a flashlight.