Converting DC locos to DCC?

Model Railroader Electronics and DCC
1

As I look at the price difference between DC and DCC locomotives the DC locos are cheaper by a good amount, and I’ve read about others who have converted DC locos to DCC by installing decoders …I think. (Or maybe I was reading about DCC-ready locos).

Anyway, is it possible to just buy a DC loco and then buy a decoder for it and (after some work) voila: a new DCC loco for less than it would have cost me to buy the DCC version in the first place?

Why do this? you ask. Well, I don’t know that I would, because the work involved would be painful for me since I’ve never done anything with decoders before.

But…

All of my old locos from the 1980s are Athearn blue box models, and I might consider retrofitting them if it isn’t a complete PITA.

But mostly because the timing of Walthers new Milwaukee Road Hiawatha F units last year was just a bit early for me and now all the DCC versions are sold out, leaving only DC units available. Would I consider trying to convert cheaper DC units? Maybe. But I’m asking for opinions on this as I am clueless.

Thanks.

https://www.walthers.com/search/sort-by/sku/sort-direction/asc/show/120?q=920-+FP7

2

Hi Andy,

As is usually the case, there isn’t one simple answer to your question. I will try to break things down a bit for you:

Regarding recent locomotives that were offered in both DC and DCC, the DC units should be easy to convert, that is if they are available! You won’t likely be saving any money but you should be able to get decoders that are pretty much ‘drop ins’. There might be some soldering involved for things like the speaker connections and maybe some accessory lighting.

Your older locomotives like the Athearns might require a bit more work. Depending on the age you might have to isolate the motor feeds and everything will have to be soldered. Don’t be put off by that. There are tons of tutorials, many on specific locomotive models, that will make the conversions easy. Once you have done a couple the rest will be a piece of cake!

If I can, I will offer just one piece of advice: If the locomotive doesn’t run smoothly on DC then adding a decoder will not cure the problem. Learn how to clean and lubricate your DC locomotives before spending any money on decoders.

Cheers!!

Dave

3

Andy,

Are you only interested in installing motor-only (non-sound) decoders in your locomotives? Or, are you thinking about sound, too?

Your older BB locomotives may need to have the motor brushes isolated from the chassis before converting to DCC. (Otherwise, an inadvertent short could fry the decoder.) Depending on the locomotive, this can be eithe fairly straightforward or involved. Newer locomotives, OTOH, generally come “DCC-ready” and will be outfitted with a 8-pin socket to plug an aftermarket decoder into. However, the term “DCC-ready” means different things to different manufacturers.

So, bottom line: Your decoder installations will have to be taken on a locomotive-by-locomotive basis.

Tom

4

With more modern releases, where the loco is offered as DC, or as a DCC with sound version, it typically costs the smae or slightly more to fit the same quality decoder and speaker to the DC version as the price difference. There’s typically no economy there, unless you are willing to use a lesser quality decoder.

It pays to keep looking though - so many of these get bought out by collectors who put them on a shelf and never run them, then end up sellign them off. I’ve gotten factory sound locos on eBay and elsewhere for less than the MSRP of the DC only version.

That said, any newer loco that is offered as a factory DCC version is easy to convert. The decoder generally just plugs in, and unless they really went to the expense of designing and manufacturing two different chassis, there’s a space for the speaker without resorting to milling the frame.

Athearn BB locos are not difficult to convert to DCC> The key is isolating the bottom of the motor from the frame, there are metal tabs on the bottom motor clip that run in the space under the motor. Cut off the tabs, or swap the top and bottom clip (but be careful, those clips also hold the motor together, with both removed, the motoi will fall apart unless you hold it together. And put a layer of thin tough tape (Kapton is the recommended type - electrical tape is too gooey and messy) over the space in the bottom of the motor, solder a wire to the bottom clip, and you are all set. There is soldering involved, and also the best way to get a power pickup is to drill a hole in the frame and tap for a brass screw which you can then solder the decoder input wire to. The bracket in front for the headlight works as an attachment point, but that rivet is often loose and makes poor contact. Solder a wire between the two truck tabs that stick up, that’s the other rail input to the decoder. Not a tough job but you do have to solder.

5

Adding DCC with sound can be more difficult because of the need for finding space for the speaker. An Athearn BB F7 for example has a big cast weight which may need milling to fit a speaker.

The only other tricky bit is the in between years when DCC ready involved an 8 pin socket on a PCB that powered the lights and usually has a radio interference (RFI?) capacitor or two that needs to be clipped. Often you remove this light board completely and use a decoder board and then you also change the lighting.

Different objectives require more or less skill and work to convert.

This site is excellent to give you numerous real installation guides which illustrate the challenges whether you buy TCS brand or a different brand:

https://tcsdcc.com/installations/wowsound

There’s a link on this page to the non sound decoder installation page.

6

Larry Puckett has a nice video that shows how to this install.

88. DCC for a Blue Box Athearn Loco - YouTube

7

I like that TCS site, and go to it frequently for info on installs.

I’ve done many Athearn BB’s, as that’s all I had when I moved to DCC.

As others have mentioned, with old DC locos, check the stall current first to make sure the motor is suitable for conversion.

Mike.

8

After you’ve done one they’re a piece of cake. I only have a dozen decoders or so but I have over 70 locomotives. I rewired all of my locomotives for DCC operation so that I can swap around my decoders if I decide I want to run one on DCC.

I have done the DCC conversion to over 30 Athearn BB diesels, Proto/Life Like and Model Power. I also have well over 30 steam locomotives that I converted.

All work fantastic on either DC or DCC.

I would also check the current draw by the motors on older locomotives and make sure you go with a decoder that can handle higher current motors if needed.

Mel

My Model Railroad
http://melvineperry.blogspot.com/

Bakersfield, California

I’m beginning to realize that aging is not for wimps.

9

So the answer to OP’s question is yes and maybe. All points made so far are valid. A few things I would add:

  1. For newer locos, check your math. It is sometimes cheaper - or more expensive to add the decoder yourself. DCC locos on sale are worth looking into!

  2. BB locos - they are relatively easy to convert if you are comfortable with the idea of opening a loco and removing drive train components. But I would say do this for sentimental reasons: the math is not in your favor if you want a smooth running loco. DCC is more sensitive to things like power hiccups, which means that you might have to change wheelsets if you still have the original wheels on them. The original wheels pick up a lot of dirt… The “gold” motors are fine, but the older motors might need to be changed. Try it on one and see what you think (don’t go out and buy a bunch of supplies…). Modern locos from the major manufacturers are very impressive…

  3. I find that sound is overrated for diesel engines, but that’s just me!

Simon

10

Hello All,

One thing that has not been talked about is the cost factor of specialty tools that will make decoder installation easier.

Unless you are dealing with locos that are “DCC Ready” with an 8-pin NMRA compliant socket you will need more than just a set of jewelers screwdrivers, about $5.00-$15.00.

Installing a decoder in a loco without this socket will require you to solder or “hardwire” the decoder, light(s), and speakers if installing sound.

A quality soldering iron will run you between $50.00-$100.00.

Good quality solder about $30.00 for a 1 lb. roll. This will last a lifetime.

You will also need heat shrink tubing to insulate the solder joints. You can find “multi-useless” packs with sizes you will never need or you can buy only the diameters you will use most often. A ballpark guestimate would be $10.00-$20.00.

An inexpensive heat gun (embossing tool) can be found at many craft stores for about $20.00.

You might also need small gauge wire (30 AWG) for things like headlights (white, yellow & blue), motor leads (orange & gray), pickups from the trucks to the decoder once the motor has been isolated (red & black), speakers (purple), etc.

Digitrax sells an assortment of nine (9) colors for about $10.00.

When isolating the motors of older Athearn B.B. locos I like to paint the cavity where the motor contacts were with liquid electrical tape- -less than $10.00.

Kapton tape (electrically isolating tape) and double-sided foam tape are also handy for decoder installations. Add another $10.00-$15.00.

For small wire gages a wire stripper is a nice “luxury” to have, about $30.00.

This comes to between $175.00-$250.00 for a one-time investment of tools and supplies.

If you are converting only one or two locomotives this hidden cost might not be practical.

However, if you are converting a fleet then the cost of DIY supplies along with the cost

11

$50-$100 buys you a good quality controlled soldering station - which will come in handy for a lot more model railroad things than installing decoders.

$10 of heat shrink is probably a long time supply, if you buy the right sizes and not an assorment that contains 8 sizes you will never use and 2 that you do.

No need for a heat gun, not with a soldering station. Turn it to the lowest setting, it will shrink but not melt the heat shrink, especially if you get the good heat shrink. (not the cheap vinyl) In fact, the good stuff doesn’t melt all over even a regular always-on soldering iron - watch the DCC Guy (Larry Puckett), he’s always shrinkign heat shrink with the tip of his iron. I still use the side, after turning my station down to the lowest setting.

Some other tools, you probably should have anyway if you are in model railroading, even if you don’t install decoders, like a set of small screwdrivers. Honestly, kapton tape, heat shrink, and spare decoder wire are probably the only things you shouldn’t have if you’ve been in the hobby any length of time and simply haven’t worked with DCC. What I really need is a roll of JUST blue decoder wire - Saving the excess cut off from other installations generally gets me plenty of all the other colors, but since blue is the function common and ends up running front to back on most diesels, it’s the one color I always need more of. I’ve barely touched any of the others in the multicolor pack I have.

–Randy

12

Heat shrink tubing is extremely useful for all sorts of electrical applications. I use all of the sizes… Even if DCC installs does not turn out to be your thing, you will probably use them for other electrical applications. As for wiring, I bought a package from ESU, gauge 36 I believe. The price is OK.

Simon

13

While I’m a lifetime DC operator and have no interest at all in changing to DCC, I have done a couple of DCC conversions for friends.

The first one was fairly easy, which included building the locomotive and modifiying the tender to accommodate the decoder (non-sound), but because the owner was not nearby, I had no means of programming the decoder. He took care of that when I delivered the otherwise ready-to-run loco…

The cast metal tender had no floor, only two projections cast as part of the tender’s body for truck-mounting. I removed those, and constructed a simple floor/underframe, and lined the all-metal tender with styrene to eliminate any chance of an accidental short between the electrical stuff and the tender…

The instructions which came with the decoder were easy to follow, so there was no real difficulty in making the proper connections.

Here’s the loco ready for delivery to the owner…

The second one, mostly completed last night, was, for me, a lot more difficult.

The installation, again non-sound, was for AirWire…basically converting an old Mantua Pacific into a Hudson, then changing it into a battery-powered locomotive - also known as “dead-rail”.
The loco was pretty-well ready to use, and, with its open-frame motor removed, rolled almost as well as a freight car when given a decent shove.

Here’s the loco and tender…

The conversion package included the decoder, a wireless hand-held throttle, and a three-cell lithium-ion battery, along with a battery charger.

Gettin

14

That adds an element of specificity that hasn’t been addressed. There are cheaper sources for Walthers locos, than Walthers, but if they are gone they are gone. We have discussed the modern business strategy of “pre-orders” many times.

If you want/need the Walthers F, and you don’t want to wait until on appears on Ebay (and at who knows what price?) installation makes complete sense. If you have a time machine handy, you would be better off going back in time and buying the DCC version, but I assume that is not an option.

Stewart F units and Life Like Geeps are popular DCC conversions.

15

IF I ever did the conversions I would do the full functionality with sound. I tend not to do things in half-measures.

16

This really cuts to the chase here. This (along with JJ’s reply) make the point that after all is said and done I may not be saving much - if any - money. Some of the tools would be a one time investment, but looking over my stock of old DC locos now I realize that ALL of them are outside of my modeled era: early 50s. They are all later designs except for an Amtrak F7 I have in the Amtrak paint scheme: so even there I would have to repaint it if nothing else.

Looks like I will need to start from scratch building a roster of motive power.

EDIT: it would be one thing if the locos I owned matched those running in that era; then I can see looking more into the conversions. But mine are all GP units from the late 60s/70s so I can’t use them on a layout based in 1950 to 1954-ish.

Grrrrrr.

Anyway, thanks for the input.

17

Okay, Andy, that’s helpful to know. While I get where you are coming from, I would disagree with you that non-sound is somehow a “half-measure”. I love DCC and enjoy sound but “in measures”. So, I don’t need sound to enjoy DCC and like F8 for muting as much as enabling sound. It’s the excellent motor & independent control that turns my crank. However, I understand that others come to this hobby for different reasons; hence why I asked you the question that I did. Thanks for replying.

Tom

18

[Y]

Mike.

19

I am very hard of hearing so sound is meaningless for me.

20

You could try QSI with 'rolling thunder". …

[:D]