Joe:

I'm really looking forward to everything you have to say about this, I'm sure it's going to help a lot of people. Like me that have never used DCC.

This could be the start of a great clinic.

I have been using an NCE Powerhouse Pro for about a year now (including the upgrade) .....

http://www.ncedcc.com/catalog2.html

.....and am now hooked on DCC for my American stuff - the handbuilt British locos will just have to put up with DC

Being someone who doesnt like to waste anything, I have mounted the transformer, booster and electrics in an old 1970's wooden speaker cabinet and the accessory power, cab bus and track bus are fed through an umbilical cable, with a 37-way connector at each end.

This means I can easily switch the system between my switching layout, test track and any future layouts, simply by wiring in a 37-way socket to each destination. It is also easy to transport.

The throttles are inserted into universal throttle panels (UTP's) around the layout and test track. I have also made room in the speaker box to transport the cable and throttles, just to keep things safe.


Jon

Joe, I have had DCC since 1994(Portland NMRA Convention). My system is near one end of the layout room, and consists of a 5 amp command station and a 5 amp booster. I thought of putting it 'centered' on the layout. Instead it is at one end of the layout room, and I have #14 wiring from the cmd/boosters to a Digitrax PM42 'power district' unit that is centered. It then is #18 wiring out to the track bus. I have a small desk/workbench/spray booth in this far end work area, and a computer that can be attached to the Digitrax Loconet. I have also ran Loconet wiring to the family room so a future 'dispatcher' can be 'remote' from the layout in the 'crew lounge'. The layout was built with 'cab control' wiring, and the #18 track feeders are run to a terminal strip. Each 'power district' was jumpered together and a run was made to the PM42. The old recessed panels have been around ever since, but will be replaced this year to make room for recessed station work areas(and places to set down your coffee). DCC has made everything 'simple' and only electrical work I have had to do is adjust/fix the old twin-coil switch machines(being replaced by Tortoise machines). The railroad DCC is protected by computer UPS's, and is powered up 24X7 from power outages.

Jim Bernier

Joe,

You've got my appetite begging for more too! Can't wait to dig in!

I have been looking forward to this clinic since the end of the scenery clinic. While I still have not purchased a DCC system, I look to do so soon. This clinic should help me in deciding what my requirements will be and then go from there.

Thanks,

Ryan

12 years with DCC...... It is amazing to me that DCC has been around as long as that. Only now does it seem to be becoming mainstream. I suppose it has taken this long for the products to reach a level of simplcity and reliability and for the costs to come down to a more widly accepted level. I am looking forward to the thread to see what I can add to my growing empire!

QUOTE: Originally posted by simon1966 12 years with DCC...... It is amazing to me that DCC has been around as long as that. Only now does it seem to be becoming mainstream. I suppose it has taken this long for the products to reach a level of simplcity and reliability and for the costs to come down to a more widly accepted level. I am looking forward to the thread to see what I can add to my growing empire!

Simon, command control moved off the drawing board and onto the layout almost 25 years ago, in the form of CTC-16. I was actually a member of an operating crew that went back and forth weekly to the basements of two CTC-16 pioneers. These guys went on to form an all command club in Denver, using PMP-112. It used to be that you had to be good with electronics to get into command control. Things have come a long way since then.

I remember ASTRAC, primarily because Allen McClelland used it on the V&O. He then went with a CTC-16 type of system which came prebuilt from John Mann in Cincinnatti. It was called "Mann-Made" (of course!). CVP's RailCommand is sort of CTC-16 on steroids as is CTC-80. NONE OF THESE SYSTEMS ARE DCC, however. DCC stands for DIGITAL Command Control. From Astract to RailCommand and in between, including On Board, Dynatrol, and some others that are long gone, those early systems were ANALOG Command Control. All of them served their purpose and all of the Digital systems out now are, as Joe says, "built to get the job done".

QUOTE: Originally posted by Big_Boy_4005 So my question is, at what point do you think it become advantageous to consider switching to DCC? The way I see it, there are 3 factors to consider. Number of locomotives, number of operators, and total square footage and the wiring implications associated with size.

Big_Boy:

It is advantageous to consider switching to DCC if you intend to independetly control more than one locomotive at a time on *any sized* layout. Otherwise, you have to buy multiple power packs and multiply the feeder wiring to the layout by the number of power packs you've just added.

It doesn't take very long before the complexity factor and the cost of all the extra toggle switches, wiring, cab control panels, etc. start to eclipse the cost of DCC.

The more locomotives you have before you go to DCC the harder it is to make the switch later, because each loco will require a decoder. Even for fleet decoders, that's $15 x the number of locos you have -- and if your fleet is very large, that won't be an insignificant expense to swallow all at once if you want to run any of your locos on your new DCC layout.

Let me add that many DCC systems have a loco '00' setting that allows you to run a loco lashup that doesn't have decoders. But that's only *ONE* lashup, and you do not get very fine control of the loco speed using this technique. The loco lashup makes harmonic sounds as you adjust the throttle, and it will cause the loco motors to heat up more than usual.

In other words, using loco '00' to run a lashup in a regular op session should not be routine practice, and the presence or lack of the ability to run a straight DC loco using address '00' should not be a deciding factor when chosing a system. At best, this is more of a stunt than anything else and not especially useful.

TOPIC THIS POST: Where to put your system
So you have your new DCC system and you need to put it somewhere under the layout -- simple question, right?

You would think so, but this basic question serves well to illustrate how 12 years experience in things DCC can come in handy because there are a lot of considerations you need to make in order to answer this question properly..

If your layout is larger in any dimension than about 15 feet, then locating your system in the layout room is not a "slam dunk". Here are the key issues that help you answer this question properly.


THROTTLE BUS
First, are you going to use a throttle bus, or are you all wireless? All wireless does give you some freedom, but be careful. Digitrax's current "wireless" solution requires you to plug in to acquire a loco, which means you'll need to run a throttle bus around the layout anyhow. [:(]

If you need to use a throttle bus, most systems don't allow you to split, fork, or T the throttle bus. It needs to be one continuous line, with a terminator of some sort (resistor, etc.) installed at the end. This means you'll simplify your throttle bus wiring and shorten its run if you locate your system at one end of the room instead of in the middle. So which end? Knowing where you want to put the programming track will help answer this question.


PROGRAMMING TRACK
Not all programming can be done on the main, so you will need to locate a programming track somewhere on your layout. I don't recommend a disconnected programming track because that will result in more handling of your locos, which can damage details.

The ideal location for a programming track is near an engine terminal in a yard, as part of a turntable lead or engine serving track. Also keep in mind the programming track is often the first place you go with a new loco as you take it from the workbench to the layout, so locating it on the end of the layout room close to the entrance can be handy.

Most systems have a length of run limit for the leads to the programming track, so it will need to be close to your system (less than 10 feet away, and the closer the better). We'll cover all the details around setting up the programming track in more detail in the next post topic.


POWER BUS
The other main issue with locating your system under the layout is the length of run for your power bus -- which are the wires that feed power to the track.

Most systems have a command station into which the throttle bus connects, so this is your input side -- meaning you send commands from your throttles to the command station, which converts your throttle settings into digital signals out to the track. But this signal is pretty low power so the command station components can be less costly. The output from the command station needs to be boosted to track power levels so it will power the dozens of locos we all dream of running.

The command station output signal goes into a power booster. Out of the power booster comes the boosted signal, with enough amps to power lots of locos. This output is your power bus, and it needs to go everywhere your track goes. Depending on the size of your layout, you'll probably need several power boosters (more on this in a later post). The foucs here is the track power bus out of your booster(s) to the track.

Most systems prefer for the low power command station signal wires that feed the signal to the booster(s) to be fairly short (again under 10 feet), so you will need to locate your boosters close to your command station.

This puts your boosters at one end of the room next to the command station in most situations. The ideal location for a power booster would be in the center of the room because that would shorten your power bus run. However, because of the other reasons given above, centrally locating your system probably isn't the best idea, so you'll have to plan for the effects that will have on your power bus wire size.

Basically, make your power bus wire guage larger rather than smaller to avoid voltage drop at the extreme far end of your power bus. You want a voltage drop of no more than 5% from end to end on your power bus. Here's a simple table that assumes 12 volts and 5 amps going through copper wire:

Length of run for no more than 5% voltage drop
16 guage – 20 ft
14 guage – 35 ft
12 guage – 50 ft *
10 guage – 80 ft

You can find voltage drop tables and calculators on the Internet – just use one of the search engines and type in “wire guage voltage drop” as your search phrase.

Notice the 12 guages line is marked with an asterisk -- that because I use 12 guage stranded wire for my power bus ... that's heavy enough I can run the 50 foot length of the layout and not get more than a 5% voltage drop.

We'll talk more about the details of installing the power bus in a future installment.


WHAT TO PUT THE SYSTEM ON
Okay, you now know where you want to put your system, but what do you put it on?

Just get yourself one of those two or three shelve short plastic utility shelving units (they're not very expensive) and put your system on that. I got a cheap set of particle board utility shelves (this was back in 1993, and they didn't have the cheap plastic shelving units then), which is also good. Don't use metal shelves because you might inadvertedly short something on the metal and not realize it.


Okay, let's get into the details of setting up your programming track in the next post.

TOPIC NEXT POST: Setting up the programming track

Simon:

Good point ... both Digitrax and Zimo use more of a peer-to-peer network for their layout "command bus" (not unlike an Ethernet computer network) which makes your "throttle/command bus" routing options more flexible if you are using wired throttes.

The disadvantage of LocoNet or Zimo's CAN-bus if you use it for other devices like turnout control or signaling is you are locked in to Digitrax or Zimo products for these things, and they can be pricey for a larger layout. If you don't take this route for turnouts and signals, then you can either use local stand-alone circuit boards or use Chubb's Computer Interface, or Rich Weyand's Tractronics system if you want to hook it all together into a computer for more sophisticated applications.

Both of Chubb's and Weyand's systems use more standard RS232 or RS485 serial communication to the devices (read: generally cheaper) and your selection options are broader -- but this is all way beyond the scope of basic DCC loco operation, which we're focusing on here.

You can also just use local pushbuttons or toggles to throw turnouts and you don't need any of this fancy stuff if you don't want it. Or you can do like I do, and throw your turnouts manually (I use 2" brass doorbolts mounted on the fascia) ... manual turnout control works well for me because all the prototype Siskiyou Line turnouts use manual switchstands at the turnouts.

Again, Simon, thanks for making this point ... as to throttle bus, Digitrax and Zimo are the least restrictive when considering your throttle bus routing options.