Several members of this forum are running DCC on 3-Rail (not me personally as I am a 2-railer that runs DCC) but DCC is just another form of command control and command control in various forms has been used on 3-Rail layouts for several decades so this DCC technology is not really new to the 3-Rail community. That being said, DCC seems to have a bit of steeper learning curve as most of the 3-Rail command control systems seem to have a more “friendly” user interface. However, if you are already familiar with one or more of the existing 3-Rail command control systems on the market, then DCC should be easier to come up to speed with than it would be for someone that just runs their 3-Rail trains on conventional AC.
Any of the major DCC system suppliers, e.g. NCE, Digitrax, ESU Loksound that can support the higher current draw demanded by the larger O scale locomotives can be used so there is no “perfect one size fits all DCC system for O scale DCC layouts”. It all depends on what you intend to do with your layout. Expect to pay around $400+ for a typical O scale-level DCC starter set. Cost goes up if you want wireless throttles or larger booster capacity. Here are some common questions you should ask yourself when choosing a DCC system:
- How many locos do wish run simultaneously and what is the total current draw (make sure to add in things like passenger cars that have internal lighting)? If the current draw exceeds the rated booster capacity, then you can just buy more boosters and divide your layout up into multiple booster districts, which leads to the next bullet item.
- Do you wish to divide up your layout into multiple booster districts and can the DCC system you choose support multiple boosters? E.g., do you have a large basement empire that requires a lot of add-on power capability or just a spare bedrooms sized layout that may only need to booster that comes with the starter set?
- Do you want wireless control, or do you want to remain stationary, or is a tethered walkaround handheld cab good enough?
- What DCC system interface are you most comfortable using (go try various DCC systems on other layouts, even if it is a different scale, e.g. HO or even N scale) and see if you like it?
- Are there other users of the DCC system brand that you are thinking of getting in your area (even if it is in a different scale) that can help you out or are you comfortable just working through issues though online forums if you have problems?
- Are you willing to lose plug-n-play support for features like automatic couplers, animated rolling stock or animated lineside structures (note: these can most likely be converted to work with DCC but may take a certain level of electronic ingenuity, such adding a DCC stationary decoder and/or adding some extra circuitry, such as a transistor or relay).
The next piece of the DCC equation has to do with the decoders. DCC is an open standard, so although the DCC system that you choose is pretty much a single-source acquisition, e.g. if you chose an XYZ brand system, then you are pretty much locked into only buying XYZ brand throttles and additional power boosters. However, devices like automatic reversers and circuit breakers can be sourced from other 3rd party suppliers and do not necessarily need to come from XYZ brand. The locomotive decoders obviously can be sourced from any DCC decoder supplier, many DCC decoder suppliers do not even make complete systems, e.g. decoder suppliers like QSI and Soundtraxx come to mind.
Here are the items that pertain to decoders:
- The BIG decoder question, which also heavily impacts cost, is do you want sound or just motor / lighting control? Sound decoders generally range from 2x to 4x more expensive than just motor/lighting decoders. Sound decoders also require speaker(s) and speaker(s) sometimes require a speaker enclosure, which you may need to build yourself to fit your specific application. If the loco is pre-equipped with sound, then you can reuse the existing speaker and just wire it up to the newly installed DCC sound decoder. A motor/lighting decoder for typical dual motor 3-Rail locomotive run around $45 (NCE makes a good basic O scale capable decoder for this
https://www.hobbylinc.com/nce-...railroad-decoder-111)
- O scale-capable sound decoders vary from around $120-$200. Also, an additional side expense that may need to be considered with sound decoders is a one-time purchase of a decoder programmer (~$100-$150) for that particular brand of sound decoder you are using, e.g. QSI, ESU. Decoder programmers can significantly ease decoder programming and also allow you to freely upload different sound files if the decoder supports that sound file model. Some sound decoders are preloaded with a full complement of supported sounds and you just change a programmable CV value to activate the prime mover sound that you want, e.g. SoundTraxx Tsunami2, TCS WOW Sound.
- Usually the hardest part of converting a locomotive is addressing the lighting and sound pieces. Getting the loco to just run on DCC is easy, just two wires in from the track and two wires out to the motor and program the address and you have a working DCC loco. Dealing with the lights (adding the right resistors, if necessary) or installing speaker(s) is the hard part.
- Lastly, steam locomotive conversions to DCC can become quite involved due to the decoder generally being installed in the tender with the motor, some lighting and possible additional speaker(s) located up in the locomotive makes things more complex. If you can reuse an existing wiring harness between the loco and tender, then that could save some significant DCC retrofit time, otherwise, you will need to make up with your own harness and source some plugs (various suppliers of RC hobby type plugs can be used).
Overall, DCC conversion on 3-Rail is very much doable; however, cost and time can add up quickly, especially when sound comes into the picture. I would like to add that DCC sound quality and motor speed control is generally far and above the level which is supplied with the OEM 3-Rail closed-source sound-equipped models. DCC sound quality especially, both in the recordings and the digital playback capability, continues to advance rapidly in the DCC open architecture than the 3-Rail closed architecture counterparts. Motor control is already pretty much top-notch and it helps to control those 3-Rail jackrabbit starts by wiring the dual vertical motor commonly found on diesels in series instead of leaving them as the come from the factory wired in parallel. DCC is not for everyone but it does have its advantages over closed-source architectures.
Scott
