Monday, December 18, 2017

Bachmann Steam Decoder Replacement Pt 2: "Sock(et)ing" a Harness, Orientation Failure, Final Install

As I mentioned last time, the next step on this decoder install is to add a socket to the wiring harness which I removed from the PCB in the tender.

The socket is on the right, with pins for attaching the harness wires.

An admittedly lousy photo, but showing the socket held on the left and the harness on the right.
It would have been great to not have to add a socket - and I suppose I could have just hardwired the decoder directly to the harness - but it's not as difficult to do as I thought it would be. And it allows me to test my install with an old decoder which is easily removable.


As with soldering wires to the plug, just remember to add heat shrink tubing to the wires beforehand, strip & flux the wire and tin the wire and pin. Bend a little hook in the wire, wrap around the pin, touch with the iron, and slide the tubing down to cover the connection.

Remember to solder the track pickup wires from the engine and tender together first before solering to the pin on the socket. And you'll need a larger bit of heat shrink tube. Yeah - I'd forgotten ALL of that and had to redo it.


VERY IMPORTANT: As with the plug, be sure and solder the correct wires to the correct pins. Unfortunately, you cannot rely on the wire colors on the Bachmann harness - you'll have to refer to your notes about what each wire does and attach it to the correct pin.


And above is the finished socket on the harness on the right, with the decoder plug on the left. The two "stray" wires (black & red) going off-photo to the right will be attached to the tender truck track pickups.


And here's everything reconnected in the tender: track pickup wires connected to the tender trucks, 8-pin socket, and wiring harness with the socket on one end and the engine-tender connectors on the other end.

So far so good . . .

I then plugged in the NCE/test decoder, powered up my NCE Powercab, cycled through the menus to activate the Programming Track, put the engine on the test track, then connected the alligator clips to the track. I figured this'd be the safest way to proceed.

Then I went to read the decoder - "No Decoder Found" was on the readout. No problem - I'd just turn the plug around. Then the readout said "Short Circuit Detected".

Whaaaaat??!!

I double checked that everything was wired properly. And it was - kinda. By that I mean that the wires on the plug were perfect (it helped that the wire colors were NMRA standard and I had another decoder to use as a guide). And it looked like the socket was wired correctly - then I realized I'd made a mistake:

The diagram I was following showed the wire configuration viewed from the socket side; I'd soldered my wires to the pins - and did them in the same configuration, but on what would be the underside of the socket. Yup - I'd manage to spend an entire evening soldering tiny wires to tiny pins and did them in mirror-image away from where they were supposed to be.

ARGH!!!!

At first I thought I'd have to undo all my work - cut off all the shrink tubing, unsolder all the tiny wires, and reconnect everything the right way. But then - in keeping with the spirit of the season - I got a Wonderful, Awful Idea:

I'd just saw the plug in half and reverse the sides!


Yup - that's what I did. And yes, it was a little tedious, and I had to use a very thin-bladed razor saw, and I had to be careful not to nick the tubing or wires. But I did it - and I'd like to think it took far less time than undoing/redoing everything. At least that's what I choose to believe.


I plugged in the test decoder again, put the engine on the programming track, and - Christmas Miracle of Miracles - it worked!


So, knowing that I had a working install, I next put a new Loksound Select decoder in my decoder tester, fired up the Lokprogrammer software, and loaded the Soo Line Mikado Full Throttle steam sound package onto it while I finished working on the engine.


Primarily, all that entailed was cleaning out some excess grease around the bull gear on the 3rd set of drivers, making sure that the chassis/running gear would roll freely without any binding, and putting the engine itself back together (I wouldn't be able to reassemble the tender until the decoder was installed).


While I had everything apart though, I explored different locations for the speaker. I ended up putting it in the tender has I'd originally planned, but as you can see above, it might be possible in this engine to cut down an iPhone speaker to fit in the weight above the drivers where the lighting currently is. It'd take some fussing, but it's probably doable. I took the photo above for reference since I may try this in the future.


But for now, I wanted to keep things simple & clean. So I used some Kapton tape to secure the wires in the engine and reassembled it.

The Loksound decoder was all ready by this time and all I did to it programming-wise was to change the address to the engine number (3304). I figured I'd play with the unmodified file for a while before decided whether/how I wanted to program it further.

So "all" that was left to do was to install the decoder and speaker in the tender. This ended up being more difficult than I'd expected, since there's a huge mounting post right in the middle toward the front that you have to work around.


But as you can see above, I finally got a configuration that would work. The socket/plug are on the floor at the back of the tender, the decoder is on top of them, and the speaker is tucked in to the side of the mounting post, secured to the tender shell with a piece of double-sided foam tape. More Kapton tape makes everything nice and tidy.

Final Verdict
The engine sounds great, with the iPhone speaker providing plenty of volume. And of course the motor control is superb, which is typical for Loksound decoders. But I think I still have a lot of work left to do on the programming. Of course, the chuffs will have to be synchronized to the drivers, but many of the volume levels on the different sounds aren't what I'm used to hearing (having actually been lucky enough to work on a few 1:1 scale steamers). And I want to move the functions around to match the configurations I have on my other Loksound-equipped engines.

But all in all, I'm certainly on my way. And no matter what changes I have to make, using a Loksound decoder means I won't have to open this engine up again if I don't want to - I can make all the changes (and even upgrades) right on the programming track.

(Heh - I guess the only reason I'll have to get back in there is if that funky socket I rigged decides to malfunction at some point. But I'll take my chances.)

With my first "real" steam locomotive DCC install now behind me, I have to admit I'm not quite ready to tackle another one yet. I want the lessons I've learned on this to sink in a bit more. And of course I have plenty of other projects to do.

Hopefully though, sharing my experience here will give you some tips and/or insight - or at the very least, warn you about a few things NOT to do! As always, you can leave feedback in the comments - I'd especially like to hear how you would have done this differently (heh - other than "buy a ready made socket & plug!") and I'm always interested in any tips/guidance or suggestions you have.

In the meantime, here's hoping you and yours are having a wonderful holiday season!

Saturday, December 16, 2017

Weekend Fun - MRH Features the Christmas Layout!

I got a pleasant surprise in the weekly newsletter/email from Model Railroad Hobbyist yesterday . . .


If you scroll down to the "Tips" section in the email, you'll see a link to a thread on "Building a Christmas Layout/Module/Diorama". Well, the accompanying photo looked pretty familiar and then, on closer inspection, I realized: "Hey! That's MY Christmas layout!"

I'd posted a bit about it on the MRH Forum this time last year, so it looks like they thought it'd be worth revisiting this year. VERY cool!

Since the above is just a pic, click here for a live hyperlink to that post.

This was just the first of a few installments on the project, which I finished in time for Christmas. So be sure to click on the link, and then scroll down that page for links to all the rest of the posts in case you missed them last year.

Of course, if you want to skip ahead, here's a direct link to the Final/Finish Fotos.

Certainly in keeping with the season - hope you enjoy!

Friday, December 15, 2017

Bachmann Steam Decoder Replacement: Disassembly, Tracing Wire, Decoder "Plugging"

As I alluded to in an earlier post, New Haven R-1 #3304 is in the backshop. I'd been having intermittent trouble with it (it'd randomly decide not to move, despite the sound working) and I suspected the decoder to be the source of the trouble. This Bachmann Mountain-type came "DCC-ready" way back in 2003 and was the first engine I ever converted, using a Soundtraxx "drop-in" decoder/speaker combo intended for a Bachmann 2-8-0 (so it was my first sound install as well).

While it's been serving me well these past 14 years, the sound was starting to sound dated - and the motor control problem was the final straw. I also wanted to try Loksound's new Full Throttle steam sound so, having a Loksound decoder on-hand (and an iPhone speaker), I figured it'd be a good time to attempt a conversion.

If you'd told me a year ago that I'd not only be able to disassemble a steam loco, but I'd be willing to remove & replace all of its electronics, I'd have called you crazy. But after attempting a few projects which others thought crazy, this didn't end up being all that intimidating. You just have to be methodical, take your time, be patient - and keep good notes!

Notes re wire routing/colors on the PCB in the engine and the PCB in the tender, as well as the NMRA standard.
(so you don't get lost, click here for an exploded diagram
- and if the worst happens, click here for spare parts)
coffee stain unnecessary
Begin by disconnecting the engine from the tender (being careful of the wiring harness/plugs), and remove the tender body shell (remove one screw and lift like a clam shell). To remove the boiler, first remove the front and rear trucks for access. There's a screw holding the smokebox to the cylinder yoke, and a screw toward the rear of the engine holding the back end.

From left to right: screw to remove drawbar to get it out of the way, screw holding the rear together, screw holding the trailing truck, screw holding the pilot truck, and screw holding the front together. NO NEED to remove the other screws - doing so would allow all the drivers to come out, which you don't want.
Once those are removed, the boiler comes off. I then removed the old SoundTraxx decoder. Thus:

Tender on left, shell in background, old decoder and boiler on/in foam cradle, chassis in front.
Next, lift the weight - which includes the motor - from the chassis, being careful of the wires. Fortunately, it lifts right off and there's no need to disassemble the chassis/running gear any further. Thus:
Remember, you can always click on an image for a larger version. Note worm gear which engages the main bull gear on the 2nd set of drivers.
By far, the biggest challenge of this conversion is figuring out what all the wires do and where they come from/go. Unfortunately, Bachmann did not use NMRA color coding on the wires - and, in fact, some of the wires that do totally different things have the same color(!!). So the best (and, unfortunately, most tedious and fraught with risk) approach is to physically trace each wire and note where it comes from, where it goes, and what it does.

These wires come from wipers on the left and right side driving wheels.


Part of the note-taking process involved physically marking the sockets with what wires go to them. In the photo above, I've unattached the small PCB at the back of the frame to 1) allow me to better see where the wires go, and 2) to make it easier to mark up. "T" is for track, "L" is for light, and "M" is for motor (left and right - I marked the "T" socket on the side for left and right as well).

Once I knew where all the wires on the engine side were coming from, it was time to figure out where they went in the tender. This is the PCB in the tender:

What's wrong in this picture?
Note all the extraneous stuff (capacitors & snubbers & such) that Bachmann added to comply with world-wide electronics standards. You don't need any of that stuff in the US (and maybe Canada?). I'd be getting rid of this board since I planned to hardwire a new socket, but first I needed to trace all the wires as I did on the engine.


Removing the two tiny silver screws allowed me to remove the board to get at all the wire tracings.

Pfffft!
And - inexplicably - I discovered that Bachmann had reversed the colors of the track/wheel wires coming from the engine (right side) and the ones coming from the tender wheels(!). I made special note of that fact.


I then traced the rest of the wires, noting which wires went to which socket and numbered the sockets according to the NMRA standard (of course, this exercise was made all the more difficult given Bachmann's color choices...)

From Lionel Strang's excellent DCC book)
Next, I cut all the wires attached to the PCB (ouch!), leaving me with a wiring harness to which I would add a new socket later.


I then turned my attention to the decoder, well, "a" decoder. Since I didn't want to risk frying a brand-new Loksound decoder, I decided to "plug" an old NCE D13SR motor-only decoder I had lying around (also from 2003, likely) for testing/diagnostic purposes.


For a plug, I used one of the plugs I'd snipped off of one of the Loksound decoders which I hardwired into my FAs.

Snipped plug on the left, with tiny wire pigtails; on the right is the socket I plan to use (those pins are what you solder the wires to)

Starting the delicate process of soldering decoder wires to the tiny pigtails on the plug.
The good news is that the snipped plugs had these little pigtails of wire to solder to. The bad news is that those pigtails were REALLY tiny! It's delicate, close work, but remember to add heat shrink tube to the decoder wire before soldering it to the pigtail, use a little flux, tin both wires, twist together, then touch with the iron. Finally, slide the shrink tube over the joint to insulate it and apply heat to shrink it in place.


And here's the NCE decoder all "plugged."  Hindsight being 20/20, next time I'll cut the wires all to similar length first so I don't get a kink caused by the shortest wire like you see above.


And that's where things stand at this point. The next step will be to "socket" (add a socket to) the wiring harness that we cut off the old tender PCB. Once that's done, we can plug the NCE/test decoder in and confirm proper operation. Then we'll know for sure that the more-expensive Loksound decoder will work and we won't let the smoke out.

If you have any tips/suggestions/guidance, please be sure to chime in. In the meantime, stay tuned for more DCC adventures!

Thursday, December 14, 2017

'tis the Season for Trains & Travel - Nauset MRR Club

Wow - what a busy few weeks! After posting my Thanksgiving Weekend progress, life got a bit crazy with Christmas stuff, visiting friends & family, and business travel. Consequently, my workbench has been in the same state as it was two weeks ago. Until last night . . . but I'll save that for tomorrow's post.

In the meantime, and relevant to this here blog, one of the places I was able to visit recently was the Nauset Model Railroad Club layout in Orleans, MA out on Cape Cod. We go about the same time every year, during their Holiday Open House, and last year included the added attraction of John Pryke's Union Freight layout. Click here for more on that visit, including photos.

This year's visit included an unexpected surprise - the addition of yet another layout! "Millvale" is an urban module built by Ben & Bob Shea (hope I got that right) for the Cape Cod Model Railroad Club and it arrived at the NMRC just about a week before our visit. As you'll see in the photos, it provides a very nice complement to John's Union Freight. In fact, the plan is to join the two layouts into one large city section.

Be sure to click the links above to visit these great clubs, even (or perhaps especially) if you can't get out to the Cape. And to whet your appetite, enjoy the photos below!















Wednesday, December 6, 2017

Wordless Wednesday #199 - Grab Shots of the Somerset Module








(with apologies for the lack of conscious composition - I need to try photostacking and photoshopping these too...)