Advice on DCC

Fred,

One recommendation I made to a friend who was considering DCC was the excellent slow speed running you could achieve using DCC with decoders which had the facilities to allow excellent slow speed control of the motor. On one of the Atlas N scale locos I have, I've timed one turn of the armature in seven seconds and I joke that I could make a clock with a circle of track and the loco running round the circle as the minute hand :-)

Jim.

"simon" wrote

I also know people who are perfectly happy with both Select and Elite systems, and also the basic Bachmann E-Zmate DCC trainset controller, but I come across far more (almost on a daily basis) who have on-going problems with all three.

On the other hand in seven or eight years of handling Lenz equipment, I've only had one customer with a serious issue, and that was down to a fault on his system, rather than a design problem or compromise.

I just wish Hornby had spent a little more time at the design and development stage before rushing their product into the market place. They'd probably have avoided much of the antagonistic response had they got it more right, first time.

John.

I can sympathise with those sentiments. Last week I emailed Hornby to get answers to why the Elite unit setting up instructions (in English) do not correspond to those which show up on the Elite screen. I have not yet had a reply but as usual found the answer myself in a supplimentary handbook lurking in the packaging of the Elite (I discard nothing these days). The Units supplied to Europe have books written in French,Spanish,Italian and German. Voil=E0, the supplement simply needed a touch of translation. Being lazy I had downloaded my English version from the Hornby website BUT there is no mention of the supplement/addendum. This little booklet does however drop hints at the potential difficulties between the Elite and (walkabout) Select and setting for more definite point control.

You can have them all, very easily. Being able to control them is the clever part ;-)

There are a couple of special DC controllers that allow you to drive DCC sound decoders on a DC layout, e.g. from QSI, but you may struggle to get british sound files and programming CVs will be a pig.

MBQ

Hi Fred,

I'm on the opposite side of the World, so I don't really know what is available on the UK market. (I build my own :-) I think "Gaugemaster" is a possibility.

Basic sound is a possibility, although good sound has come since DCC so every unit/system I'm aware of is related to DCC - some sound decoders will operate on DC track current, but whistles, brake noise, coal shovelling etc are inaccessible. A US firm makes a DC controller which will access all those additional sounds.

Engine lights can be operated in a number of different ways, the simplest is to have a pair of series diodes in the motor feed driving a 1.5 v bulb. Carriage lights get a bit more complicated, basically a voltage regulator and 1.5v bulbs or LEDs. Alternatively some button cell batteries with or without track charging. Switching them on/off can be biased reed switches or relays or ...

There's also a half-way house, suited to small and shelf layouts, where you use DCC with a big decoder on the baseboard powering the track. Sound (moduls) attached to the decoder can then drive baseboard mounted speaker(s) (or amplifier/speakers) for better sound reproduction.

Advantage DCC: everything is "off the shelf" and only requires programming skills and money money money.

Advantage DC: the basics are available off the shelf and the additions require that you gain skills in basic electronics and modelling. (oh, and you need a brain ;-)

Once you get into complex stations with 4-100 locos _running_ DCC holds all the cards over DC.

If you get interested in proper railway signalling DC wins.

Greg.P. NZ

Real locomotives generally don't run at less than about 4mph/6kmh. What is noticable on both prototype and good models is that they accelerate smoothly from zero to that speed and deaccellerate through that speed back to zero. Way back when I started building controllers I tested my collection of 50s/60s/70s locos and found most of them would run smoothly down to about 1/7th of their maximum speed ie a loco that would reach 100 scale km/hr would go from 0 to about 14 km/hr instantly. It could then be slowed to about 7 km/hr without stalling. However good my controller design got I couldn't improve much on that.

Greg.P.

Why the last statement ? I see no massive difference between DC and DCC in terms of prototypical accuracy; its possible to do prototypical signalling in both and possible (normal!) to ignore it in both. If you mean electrical switching of sections under DC control following signal settings, this isn't prototypical !

- Nigel

A lot depends on what one is modelling. For example a branch line terminus station will be controlled by a small number of railway staff whose actions can be simulated by an individual modeller/operator.

- Station Master.

- Porter/ticket officer.

- signalman.

- loco driver.

- fireman.

- shunter. Move up the prototype ladder to a busy (small) station on a double track mainline and one would be a very busy little operator!

I have such a layout - double track mainline station looping to a staging yard, with one direction supposedly being the end of a suburban service and the other direction representing the world Eastwards. There's no way (other than a 'slow clock') that I can do all the prototypical tasks to match the prototype timetable, and then of course there would be long idle spells. (ie 'fast clock' operations are a neccessity)

- Being the loco driver only isn't very rewarding as the trains travel the length of the baseboard before disappearing to staging.

- Being the signalman is more interesting as routes, turnouts and signals are interlocked.

- Being stationmaster can be interesting.

- I have to be the shunter and loco depot supervisor at the same time as one of the above unless I have visitors.

Admittedly I can't ignore the signalling when multiple trains run conflicting routes, as one can with DCC, because the routing (turnouts and signals) link controller to block. I can set several non-conflicting routes plus yard and run roundy roundy if I feel like it. I did consider DCC but there was no way to achieve what I wanted with any less wiring but it would have cost vastly more.

I did try to design the same sort of control for a friend who was building a fairly large Swiss city terminus station. I happily admit my system wasn't going to work with 5 incoming lines leading to 12 platform roads, even with both overhead and track power. There was no reasonable was to get the shunting locos across the throat to withdraw the rakes of coaches. I got the (paid)job of fitting decoders to his collection of locos. (win-win) Somewhere along the way his huge Swiss terminus became a Rhatischebahn mountain branch.

Greg.P.

Yes, fine as far as the answer goes. You have a solution which works in DC. But, you haven't been able to show it couldn't also be implemented with DCC. I agree the wiring is different, and in individual circumstances one or the other may need more wire or more components.

But, at the statement you originally made was "If you get interested in proper railway signalling DC wins" I see nothing to support that in the general case.

I am of the view that there are solutions for both DC and DCC which can give correct operation, and solutions which give "train set rules running" with various degrees of approximation to the prototype.

- Nigel

OK, very simple examples:

- DCC is based on and requires the operator to control every train. (I don't want to limit my layout to the number of trains I can drive, I want it to mimic my chosen prototype) another:

- DCC allows the driver to run through signals and mis-set turnouts. (Exactly why would I want to endanger my $500- locos???)

- DCC requires me to precisely identify the loco I wish to drive by it's specific number. That's fine if one is operating US locos with scale 6 foot high running numbers, but my locos have numbers I can't identify from more than about 2 feet, and not at all if they are in the hidden staging yard.

Greg.P.

DCC might be described that way in some advertising and some magazine articles. But, its not a fundamental requirement that it is used that way.

I have automated DCC running without computers. Set the trains running, they stop at signals. Clear the signal and train accelerates away again.

Add a computer and much more complex automated running becomes very simple.

Incorrect, see above. (My locos are irreplacable, I've spend years scratch building the things )

Further, we were talking of prototypical operations. On a real railway drivers do drive past signals, then, on modern signalling systems only, an automated system will intervene and stop the train. Quite possible to implement any of that on DCC. Or assume our drivers do follow the signals and use the methods alluded to above and stop the train ahead of signals.

I can select locos by a huge picture of the loco in question, or a written description. I could use automated methods to tell me where the locos are located.

Sorry, you are misunderstanding or misrepresenting what is possible.

I stand by my original point; there is nothing in DCC or DC which makes prototypical operation more or less possible. For each individual person, and each individual model, there may be combinations which make one approach more or less attractive on factors such as ease of understanding how the system works, cost, or volume or wire, etc..

I am quite content that you have a DC solution which works for you. And it may be the right solution for others.

- Nigel

Write direct to NCE including your credit card details - you'll get an excellent product at a very competitive price! Even better, they respond sensibly to queries and they replace faulty products without question.

Greg.P. (satisfied customer)

I have all that without DCC! So why would I buy DCC? :-)

I wrote the monstary value in to suit all readers - I have a mix of proprietry and scratch-built, very few of which I would allow to be damaged in that manner.

Didn't the GWR start that around 1912? The German Railways began installing their system in the mid-1920s.

I too can do that by stappling cut-out catalogue pictures to the wall. ;-) I have multiples of several classes of loco, only distiguishable by reading the running number.

Me too, but automated methods at the human interface still require human recognition and input - by my count that's _three_ steps when an error can be made. My system reduces that to _two_. When my trains are parked in the staging yard, I need only retrieve the track and train number. I have no need for the loco number or the address. That's half the amount of information you need. (in the same situation)

Absolutely anything is possible. It is the cost and degree of difficulty we are at odds over.

Most DCC enthusiasts repeat the advertising slogans " DCC, the way of the future" etc. Nowhere (that I have seen) do they ask the question of the newcommer "is DCC or DC best suited to your situation and needs?"

Regards, Greg.P.

The problem here is that the newbie will have been exposed solely to advertising. Coming into the game via a club will inevitably lead to the clubs preferred method or at least that of the richest/noisiest expert.

I am finding that the remote accessory controls are not sufficiently positive or reliable so my solution is to revert to my old DC system with my version of a CDU which garauntees a movement. This of course is giving rise to more and more wire just for point control. Once a working system has been established there will be the lighting and maybe signalling and train detection etc etc. All these things will generate cabling which would exist for DCC or DC.

DC enabled me to run more trains simultaneously but DCC makes same track work easier and does illiminate isolating sections( although they still have a place in DCC systems in my view.).

That's NOT a DCC issue, but your choice of components. Choose accessory decoders that have or can be used with a CDU.

MBQ

That's the sort of thing that you find out _after_ you've made your choice of equipment :-(

Here in NZ there's not a lot of choice over the counter, so we tend to buy from catalogues in bulk. As always, it's a matter of knowing what questions to ask and then recognising the sensible answer.

Greg.P.

Here in the UK there is not a lot of choice over the counter of a local model shop; a couple of main brands and staff who are not particularly expert. One tends to buy mail order from a handful of specialists. Information in advance comes from trawling the internet.

I don't think there is that much difference.

Agreed.

- Nigel

Hi Guys.

Thank you all for your input. I have decieded not to come back into model railways. It is too complicated and expensive for me.

Fred

Hi Fred, don't let us put you off - we like to argue but you don't have to. Model railways can still be done cheaply, in fact per average income it is far cheaper than it was 50 years ago.

Greg.P.