Hi Folks. New to the Forum. Here’s the first of what will probably be a series of dumb questions.
I have an exisitng double mainline layout built 30 years ago which is undergoing complete renovation - new track & turnouts, smoothing roadbeds, readjusting grades, repairing some sagging overpasses, upgrading wiring, etc. A couple years ago I replaced the power packs with MTH DCS Commander and their 100 watt power supply, one for each track.
Since everything is essentially already in place for DC (like the control panel), I plan on running two power districts for DCC - one for each mainline. I typically run rather long trains (or two trains on one tracks). Because of the length, grades and curves I’ve found I get better performance using four to six powered locomotives on most trains. There will also be a double revering loop added on the inside mailine track and three or four additional sidings (there’s one existing short passing track).
I guess my first “dumb” question is, should I use a single or separate (2) common (-) buss wires, one for each track (or more for each siding), or can the (-) feeders just be tied to one common buss but use a different (separate) buss for the + side of the connections of each mainline?
I don’t intend to run both DC and DCC simultaneously, however I suspect that I probably could run DC on one mailine and DCC on ther mainline at the same time since all the old fashioned cab control blocks will still be in place.
So this is a cab control system where each controller can control each track, or is one control dedicated to one part of the layout?
Common wire schemes are asking for trouble. I recommend insulating both rails. Run a two wire bus for each block. Of course if you were going straight DCC a single bus could service both tracks, and save a bunch of wire.
In theory yes. In practice if the two “main lines” cross over to each other and a train accidentially takes that crossover so that it bridges the gap between the two systems it could fry the loco, the DCC controller, the DC controller, or all three. Basically that is a bad idea.
The only way to safely operate a DC/DCC layout is to have one or the other operate at one time, not both at once. That is accomplished with a DPDT center off switch back at the beginning of your power sources to the track, or layout wiring, only one power source can be on at one time, eliminating the possiblity of a problem of messing up something. The Safest Way! Your crossovers, should of been both rails insulated at the crossovers to begin with, unless you used common rail,which I personally detest. Atlas came out with that years ago to try to simplify wiring with the products they had on the market, not the best as far as relliability goes. My opinon only.
For safety, you should never try to run both DC and DCC at the same time unless there is absolutely no connection anywhere between lines that a locomotive could inadvertently cross. Depending how how high the DC throttle is set, your DCC command station can be destroyed.
You didn’t say how big your layout was, but if you’ve already got the 2 main lines which are already electrically isolated it would be best to keep them that way. For most home layouts, you won’t need a booster to add DCC power, although with the number of engines you run, you might. Having the main lines isolated will make it easier to install a booster. If not, you should consider using separate circuit breakers to break the layout into districts. This will help operationally, and will make troubleshooting easier as well.
Yes, this was originally wired as a cab control system where each controller (power pack) is typically dedicated to one mainline. There are 6 isolated blocks on each mainline and one isolated passing siding. Each block has a DPDT center off toggle switch that controls which power pack can be used on any block on either mainline.
Originally I wired each block with its own +/- pair. There was no buss. These wires are not a heavy enough gauge to tolerate the current used in DCC. Indeed, over the years I came to realize that I was getting severe voltage drop at the farthest ends of the layout. There are only one pair of wires to each block.
A few years ago I installed a stranded 10 gauge common buss for the minus side of the DC power and four 18 gauge feeders from the common buss to each block on both mainlines on one rail only. This was enough to improve voltage regulation dramatically. I also assumed that this would begin to prepare the layout for DCC but now I’m not so sure this is a good approach.
Several years ago I visited the Elmhurst Model Railroad club and they said they could run both DC and DCC. I figured eventually I would do the same but it’s sounding more and more like this a bad idea with one operator running multiple trains on multiple tracks which could set the stage for a potentially very expensive accident especially since there is a stretch of track with double crossovers so trains can switch from one mainline to the other.
What I was hoping to do until I get enough of my DC locomotives converted to DCC was to be able to run one mainline on DC and the other DCC. The control panel has a DPDT center off toggle switch for each block so I figured if I keep the toggles thrown all one way for one mainline and thrown the other way for the second mainline (which is how it is operated now in DC with two transformers) I could use the MTH Commander controller which has a DCC pass-through switch to use DCC on one of the mainlines. However, as mentioned above, I currently use one 10 gauge buss for one side of power supply to all tracks and this hasn’t seemed to create any problems so I’m wondering if can continue with this sort of single buss common when adding DCC with the intention of at least temporarily using DCC on one mainline and DCC on the other. From the responses so far it appears the answer is no.
The other thing is I figured I could basically split the layout into two power districts, one for each mainline by simply switching the toggles on one track one way and the other way for the second power district on the other mainline.
The layout was 6’ x 18’, double mainline double loop, so about 90’ of track/mainline. I typically run one long (50+ cars) on one track and a long full length passenger train on the other, sometimes with a second shorter freight or passenger on the same track.
I decided it would be better to just do a complete renovation instead trying to piecemeal fix a number of problems and in the process expand and upgrade the whole layout.
I’d like to post some pictures but haven’t figured out how to upload an image yet.
Separate returns lines are almost a necessity due primarily to the need to diagnose shorts. Your reversing loops will require a rewiring for DCC. Several manufacturer’s (MRC, Digitrax, Circuitron, etc.) make reversing modules for DCC application. Circuitron also makes a DC reversing module but you cannot run DC through a DCC reversing module. These DCC reversing modules make it impossible to run DC mode. You can run DC engines on the Digitrax stretch zero mode which assigns engine ID=zero and runs the DC engine using DCC control. This method is controversial and has the potential to damage motors…especially coreless motors. I use it all the time w/0 any problems but you cannot leave a DC engine on a powered track for any extended period of time as the motor may get too hot. You have to kill the power or remove the engine.
Not to complicate things, but obviously I have to choose a DCC system to use. I’ve read/heard all the “Ford vs. Chevy” arguments. But yesterday while speaking with a Lenz dealer he mentioned the Roco Z21.
I recently added a laptop PC to my audio system to use as a digital media center for playing high resolution audio files and now use a tablet as a remote control for the laptop/media software/music albums/tracks to play. So this Roco Z21 really piqued my curiosity since it can use a tablet as a graphic control interface instead of the hardware based handheld DCC type devices. The Z21/tablet combination apparently has many capabilities simply not available with other DCC systems.
Anyone have any experience with the Z21 or know someone who does?? Opinions?
You can wire a reverse loop through a DPDT toggle switch and it can be used for both DC and DCC operation, but your train has to stop within the loop as the toggle switch is thrown.
A DC throttle has to also be set to go in the opposite direction after the toggle switch is thrown so the train doesn’t back up.
With DCC the train will continue to go forward after the toggle switch is thrown without having to change the throttle direction setting.
When I started building my layout, I thought I would build it with the option to run DC or DCC, since I had some DC engines already. But, when I installed a decoder and ran my first DCC engine back and forth along about 6 feet of track, I took the DC powerpack off the layout and put it under the table, never to run DC again. (The powerpack now runs my turntable and some LEDs.)
This may be your experience, too. DCC added a lot to running trains for me.
Similarly, once I got my first couple of sound engines, all my non-sound engines spent their days in the roundhouse until they were upgraded. It’s just the way it worked out.
Our club was built in the early 1980’s with common rail, fourteen blocks, one reversing loop, HO scale. When we went to DCC about seven or so years ago using a NCE 5 amp Power Pro, we tried running a block or two in DCC and a couple others in DC. One time we were gabbing and a loco crossed a block gap. Fried the booster. No one was watching the control panel. From then on, no DC operations anymore.
To be honest I have so many locomotives its not funny. And I’m pretty sure virtually everything I’ve bought in the last 5-7 or more is DCC ready, and there’s a lot of those. Lots of Athearn Genesis, Proto 2000 that just need the board swapped out & some Broadway Limited. The truely DC only stuff hasn’t been run in years. I’m probably fooling myself to believe that I’ll have the time to convert any significant number of these to DCC in the near future.
Since I’m putting in all new track and turnouts it sounds like it’s still a good idea to put the “original” insulated blocks in place with discrete busses for each block if for nothing else than trouble shooting and just start installing DCC chips in my newer locomotives. And that way I can also use the two MTH power supplies and split the two mainlines into separate power districts. The old control panel still in place and all I have to modify is to get rid of the single common return and run separate busses to each block.
Last year I totally rewired our large HO scale club layout that had originally been built for DC block control operation, since no one seemed to be running DC locomotives.
I eliminated six control panels containing a total of around 200 block toggle switches and at least two miles of wire, perhaps more.
Our layout is now 100% DCC operation using NCE ProCab Radio throttles.
If someone brings in a new or used locomotive and wants to test run it, we have a piece of flex track and MRC power pack that can be used for that purpose. Then they invariably want a decoder installed unless they intend to run it on a home layout that is DC only.
Sounds like you are in the same boat as me, but I never intended to convert all my locos. As it turns out converting them as I need/want them has been a great solution. I am guessing my fleet will never be “all” converted. I’ve still got a sizable roster of CTC-16 and Railcommand equipped locos.
I don’t know. That totally depends on the track plan. The only reasons you want insluated blocks in a DCC system are: 1. to prevent short circuits from things like hot frog turnouts and reversing loops. 2. Separate the layout into smaller power districts because a single booster can’t handle it. 3. Isolated short circuits to one section of the layout. Our club isolated the main yard from the main so that the often shorting yard wouldn’t stop the trains on the main. And finally 4. Signalling.
I would physically block any crossovers between the two mainlines so a loco could not accidentally cross the electrical boundary.
Zephyr, you’re comments are well taken. I think I could drill a couple of holes in the roadbed at the crossovers where I could insert a couple of plastic dowels, kind of like concrete filled steel ballard posts we see protecting building corners and signs in tight parking lots/driveways. Of course the train would crash into these if something was accidentally switched wrong but it’s better than letting the locomotive pass through and destroying who knows what else. I tend to run my trains at lower speeds. To me it looks more realistic on my layout so the dowel barriers should easily sustain the impact.
The other thing I should mention is that the MTH DCS Commanders I use (two - one for each mainline) are DCC compatible. It has selectable control mode configurations for analog DC, DCC and DCS. For the most part I always have all the control panel toggles for one mailine switched to use one DCS Commander & power supply and the other mainline control panel toggles thrown the other way to use the second DCS Commander & its power supply. Both tracks (and all blocks) are electrically isolated and there will no common rail as in the past. I’m going to rewire all the blocks discretely with their own buss & feeders. Both rails isolated between all blocks.
If something can go wrong it will. [zzz] [#oops] [W] [8o|]
Roco, made in Austria, is not very well known or supported in the U.S., so I would be rather cautious about purchasing their DCC system.
Digitrax, NCE, and CVP systems are made in the U.S., and service and support are readily available in the U.S. Not so with some of the products made in Europe or China.
Just some observations from a guy who has played with trains since the early 1950s…
Often, redoing a layout is more trouble (now and later) than tearing it down and starting over. Sounds like you are well on your way so I wish you luck.
While its possible to mix DC and DCC, I would urge you to go one way or the other. I did make the switch to DCC in 2008, and have been very happy with it.
If you do go with DCC, go with NCE or Digitrax or even CVP. Your support from the factory and this Forum will be much more substantial, parts/supplies are much more readily available, and these systems all work great.
It sounds like you know this, but I’ll say it anyway… make your wiring bulletproof. Put in lots of feeders, perhaps every 4 feet and on every siding, etc. This especially applies to DCC, but is a good thing for DC as well.
Make yourself a work plan. With a sizeable layout, its easy to jump into the deep end of the pool…
I know this is an older discussion, but I feel a little more research might be necessary, you are incorrect about the tablet control. First, I’m VERY budget minded and I’ve set up DCC very inexpensiviely, that runs on G scale, and I’ve also simply hooked the same system to HO and N, and at one time at the same time!
Let me tell you about my setup. First, I bought a almost new NCE Power Cab, yes the basic starter set, for very little $$. However, it is VERY expandable. The power cab comes with a panel that lets you expand, you can expand to as many as you’d like. You can also use the Power Cab as a Pro Cab on an other NCE system! Next, I bought a couple of boosters, don’t limit yourself to the brand you have, no need for that, you can wire just about any booster to the other brands. I bought two slightly older 8 AMP MRC boosters, now problem wiring up with my Power Cab. Also, since I’ve moved a lot, and setup temp layouts (mostly G scale!, yes indoors), I’ve gotten good at doing this. Third, I bought a Bachmann 5 Amp booster, got REAL bargarins on the boosters, look around you can find them. The Bachmann works great on my temp layouts, is easy, fan cooled, and I don’t need the 8 Amps right now or mulitple districts ATT. I mounted my NCE panel in a little plastic box.
Finally, I purchased the NCE USB panel, it plugs into the other port on my panel then plugs into the laptop via USB cable. However, the BEST part is the software is free, I use the JMRI software (see here: http:/