Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

CONVERTING A DC LAYOUT WITH BLOCKS TO DCC

9787 views
47 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    January 2009
  • From: Maryland
  • 12,897 posts
Posted by ATLANTIC CENTRAL on Thursday, June 13, 2019 1:12 PM

Johniacono
Yes but what about reversing loops
 

Didn't you think there were reverse loops before DCC?

This stuff cracks me up.

DCC can be easier than DC, or it can be much harder. Goals, needs, layout size, loco fleet, all play a role.

All generalizations are false.......

I can see where a layout full of common rail and power routing turnouts could present some challenges to DCC.

Just a reminder, and note to the newbies, I run DC, multi train operation, with radio throttles, no toggles to flip (not even for reverse loops), with signals, detection, automatic train control, CTC and more.

It is complex to build? Sure. Is it complex to use? No. In fact, taking a train around my mainline involves about the same number of "data entries" (buttons to push, yes I use buttons, not toggles, and you are not stuck at one control panel) as a similar DCC layout would require.

If the Dispatcher is on duty, all you do is drive your train and obey the signals. If you run a red signal, does someone else take control of your train? No, you train simply stops....

Ok, back to your regularly scheduled DC vs DCC comments.

Sheldon

    

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Thursday, June 13, 2019 12:30 PM

richg1998
At least you understand a little about complexity DCC. If it was fairly easy as someone here as said there would not be so many questions in this forum.

Actually, DCC is simpler than DC, but as with many things, it can seem complicated at first. Wiring up a large DC layout with multiple blocks and toggle switches and reverse loop switches is a lot harder than doing a DCC layout.

I think a big part of the problem is that because DCC offers so many options - things like setting decoder CVs for example - that people may get overwhelmed because they don't understand they are options, not requirements. If you buy a locomotive equipped with DCC and sound, you probably should change the ID no. of the decoder from 03 to a separate number...usually the number of the engine it's in. That will allow you to control each engine independent from your other engines. The rest - sound volumes, speed settings, horn or bell sound etc. - are pre-programmed at the factory. If you like the way everything is, just changing the ID is all you really need to do.

Stix
  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Thursday, June 13, 2019 11:57 AM

When our club converted to DCC about ten years ago we put a reverser on a reverse loop and a crossover. We use to run only in one direction when we ran DC. No need for the DPDT swich anymore.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    April 2011
  • From: About 20 minutes from IRM
  • 430 posts
Posted by CGW121 on Thursday, June 13, 2019 11:49 AM

That what automatic reversers are for. Digitrax makes one someone else does as well. I have a Digitrax one which has worked flawlessly for 5 years or so.

             Mike

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Thursday, June 13, 2019 11:47 AM

Since he has a DC set, he used a DPDT switch.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    January 2002
  • From: US
  • 7 posts
Posted by Johniacono on Thursday, June 13, 2019 11:42 AM
Yes but what about reversing loops
  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Thursday, June 13, 2019 10:41 AM

JGHowes
My experience with DCC conversion was regrettably unsuccessful and I reverted back to DC. My 30 year-old layout is very large and complex‎, with many blocks, common rail, non-DCC friendly turnouts and double-slip crossovers, many locomotives running multiple lash-ups to power long trains over grades, and small gauge wiring over distances. Locomotives that ran perfectly on DC ran poorly if at all when DCC decoders were added. 
 
The only DCC I have now is a separate streetcar line running on city streets.
 

Welcome.

Well that is a bit of good news. Doing model railroding your way and having a good time. At least you understand a little about complexity DCC. If it was fairly easy as someone here as said there would not be so many questions in this forum.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    October 2007
  • 1 posts
Posted by JGHowes on Thursday, June 13, 2019 9:27 AM
My experience with DCC conversion was regrettably unsuccessful and I reverted back to DC. My 30 year-old layout is very large and complex‎, with many blocks, common rail, non-DCC friendly turnouts and double-slip crossovers, many locomotives running multiple lash-ups to power long trains over grades, and small gauge wiring over distances. Locomotives that ran perfectly on DC ran poorly if at all when DCC decoders were added. 
 
The only DCC I have now is a separate streetcar line running on city streets.
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, June 4, 2019 6:28 PM

 Even in pre-DCC days I was very much against common rail - I built plans from the Atlas books but I NEVER wired them common rail, always BOTH tracks insulated and 2 wires to the blocks.

 But either way - as long as there are multiple feeders to the common side, or it's a VERY small layout, just hook the DCC system in place of one DC cab and throw all the block toggles to that cab. Disconenct the second (or other) DC cabs though - you do not EVER want to mix DC and DCC, even accidently. Somethign will fry, most likely the DCC system. The only safe way to support both is either a plugin system or a DPDT center off toggle so that one way, the entire layout is DCC and the other way, the entire layout is DC. Both at the same time is asking for trouble, all it takes is one loco crossing the gap and bridging a DC block to a DCC block.

                                           --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Tuesday, June 4, 2019 12:48 PM

If your current layout has both rails insulated between each block, you don't need to do any additional wiring for DCC. If your layout works well now in DC, it will work well on DCC.  Just replace one of your DC power packs with a DCC system - the two wires now connected to the power packs variable DC output goes to the DCC system instead.

Stix
  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Monday, June 3, 2019 4:29 PM

Hello All,

How big a layout are we talking about?

What scale?

How many blocks do you have now and how are they currently controlled; Atlas switches, DPDT, something else?

What gage of wire are you using now to power the DC blocks?

I wired 16 blocks on my 4'x8' HO pike through terminal strips to Atlas controllers with two cabs with 20ga stranded wire.

When I converted to DCC I harvested a lot of wire and insulating rail joiners.

With the terminal block wiring and the size of my pike I kept the 20ga feeders to each block.

The terminal strips are centrally located so each feeder run is approximately the same with no run over three feet in length.

I am in the process of soldering most of the rail joiners, because I used sectional track rather than flex track.

Also I have no under pike access so an around the layout bus is not feasible.

I run all of my wiring through automotive flex tubing imbedded into the 1-inch foam, similar to prototypical utilities.

The more specific information you can give the fine folks on these forums the better they can assist in answering your questions.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Sunday, June 2, 2019 7:49 PM

When I started my current layout I designed it for DC operation back in 1988.  It had 24 and still has 24 total blocks which includes all the sidings and yard.  Each block is wired through a DPDT center off toggle switch, forward-off-reverse.
 
My main is a double loop up and over forming a double track mainline on the yard/passenger station level.  The mainline has 120’ of mixed code 100 and code 83 HO Atlas flex track with a 3½% grade and helix. Code 100 track in hidden areas, all viewable track is code 83.  There are 8 blocks on my mainline.
 
When I went with DCC in the early 2000s I decided to follow the DCC masters way by rewiring my layout using the DCC under table #14AWG Solid wire buss.  For me that was a terrible mistake plus a total waste of time and money.  I lost all of the ability to run my trains the way I had for 56 years using block control.  After giving DCC a good try I rewired my layout back to the original DC operation.
 
After everything was working again for DC operation I removed the track power from my MRC DC power pack (Sound & Power 7000) and hooked up my new MRC Prodigy DCC Controller and it worked perfect first try.
 
I’ve been running dual mode (one or the other) for 12 years without any problems at all, both my DC operation and my DCC operation work great.  I run about 70% of my time in DC mode and 30% in DCC.
 
I built an interlock to prevent the DC power pack and the DCC Controller from connecting to the track simultaneously.  A simple DPDT relay to select either the DC or DCC power for track power, the relay coil is operated from the DC power pack accessory power.  The relay switches the track from the DCC controller to the DC power pack when the DC power pack is turned on. 
 
I have a over 70 locomotives, way to many to convert to DCC ($$$).  I have about a dozen decoders and I don’t plan on buying any more.  I wired my entire fleet of locomotives for DCC operation so if some reason I want to run a specific locomotive on DCC I simply swap in a decoder, diesel or steam.
 
I have 20 Rivarossi articulated locomotives and only two decoders with the true SP AC-9 to AC-12 sound, I have two generic (no equipment number) SP oil tenders equipped with the SP Articulated Sound Decoders that will run behind any SP Articulated locomotive, easy tender swap.
 
My bottom line is if your layout works OK on DC it will also work on DCC.  The DCC digital rate isn’t high speed data, it doesn’t require the super DCC buss wiring to work correctly.  For someone starting out the DCC buss is much simpler to wire but for an existing layout it isn’t needed.
 
I haven’t had any problems with DCC operations on my DC wired layout, it has worked perfect for over 12 years.
 
I might add that my great grand kids (5 to 14 years old) can operate my layout without problems too.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

 

  • Member since
    January 2010
  • From: Chi-Town
  • 7,712 posts
Posted by zstripe on Sunday, June 2, 2019 5:52 PM

If Your layout was wired for common rail, (one rail insulated) it would be a good idea to add feeders to the common rail, not to rely on rail joiners. Your gauge wire should be good enough, unless you used anything smaller than 22 for a medium size layout. No need to add any bus wires.

If Your layout was wired with both rails insulated, You should be good to go without adding any wires. Just a matter of removing the DC power packs and replacing with a DCC system. You will know if you have to add any more feeders when up and running, if trains slow down in some area's. No need to get involved with adding all kinds of feeders until you need them. Set all block switches or controls to one Cab like A or B for DCC. If You want to keep the layout for use in DC and DCC, install a DPDT Center off toggle switch, in between the DC and DCC systems so you can only use one system at a time.

That is how My layout is set-up.......It is a 3 cab 46 block double mainline layout. Been in HO DC since 1950 when I was 8yrs, old. The layout in the last sentence has been working flawlessly since 1980.......it is My last.

Take Care! Big Smile

Frank

 

  • Member since
    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Sunday, June 2, 2019 5:48 PM

The club I belonged to had four throttle and fourteen blocks and one reverse loop.

We switched all blocks on and eventually ran #14 buss and used the block feeders. We kept them to about six to eight inches long. We had common rail. We put in a reverser for the reverse loop.

We tried DC and DCC in a few blocks before the #14 buss but fried the DCC booster with a cross over. No more. All DCC.

Edit.

I was just reminded, we did add feeders to the common rail every few feet. Something I often forget to mention. I should remember. I spent a lot of time under the layout on a creeper with a raised back and a cup of coffee.

Rich

If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Sunday, June 2, 2019 5:42 PM

I built my lay out for both, as I started in DC, and then went to DCC as my decoder equiped fleet grew.  I can still easily go back forth from DC to DCC.

I wired it with a buss and feeders, but for the "blocks", I gapped both rails, and didn't use the "common rail" DC method of wiring.

I guess it depends on how you initially wired your lay out.

The spacing for feeders is up to you.  I kept the "blocks", and I ran at least two feeders to each block.  As in DC cab control, each of my blocks are seperately controlled, so I can turn off any block I need to. 

Mike.

 

  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Sunday, June 2, 2019 5:39 PM

trevorsmith3489
When I converted from DC to DCC many years ago I just switched all the blocks to ON and swapped the two wires from the controller to my new Lenz DCC controller.

Same here, except mine was Digitrax. I ran that way for about a year before getting into a "DCC upgrade" plan.

IF your original DC wiring is "robust" in other words, the wire gauge sizes are reasonably sized, and your block toggle switches reliable, you won't have any problems.

Many "convertees" myself included, later removed the block switches and added additional feeders to the track where needed. Much of the "block" wiring was removed just to simplify the neatness of the wiring under the layout. In some places I had wiring for five DC cabs.

Sure, if you were building from scratch you could "design for DCC" but there's no reason why a well-wired DC layout won't run DCC just as well.

All my turnouts were the "pre 'DCC-Friendly'" Walthers Shinohara code 83s and they only rarely caused any electrical problems.

By upgrading small areas of the layout at a time I could still keep trains running and down-time to a minimum while I made the "improvements" to the buss and feeder system.

As others have pointed out, don't be tempted to keep part of the layout on DC control while having DCC as well. This is a recipe for disaster. One or the other — not both!

Hope that helps, Ed

  • Member since
    October 2006
  • 89 posts
Posted by trevorsmith3489 on Sunday, June 2, 2019 5:31 PM

When I converted from DC to DCC many years ago I just switched all the blocks to ON and swapped the two wires from the controller to my new Lenz DCC controller. 

Worked fine with no additions or alterations to the wiring.

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Sunday, June 2, 2019 5:25 PM

RR_Mel is going to be your man because he is at the intersectionality of electrical diversity and inclusion.

Modern babble speak aside, he concluded that wiring for DCC was a mistake and reverted to his DC wiring which is capable of running either DC or DCC, but not both at the same time.

DCC does need adequate wire gauge over distance, so if you DC layout is wired with telephone wire, it may need upgraded.

Blocks are useful if you want to park locos and lighted cars and not have them gobble up electricity or make noise and light.  For instance the Bachmann sound value locos insist on starting up when you power up the track and there is no way to deprogram them. 

Blocks are not needed for preventing train A crashing into train B in DCC if you have engineers paying attention.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    October 2007
  • 29 posts
CONVERTING A DC LAYOUT WITH BLOCKS TO DCC
Posted by LLOYD on Sunday, June 2, 2019 5:10 PM

My current DC layout has many blocks and I want to convert to DCC, my question is:  When adding bus wires and feeder wires do I still need to add feeders every 3 feet or so, and if adding feeders won't this cancel my block sysyem or will it make any difference because with DCC I don't need blocks.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!