Failure! Sometimes I hate DCC! Or... Tomix Track Cleaning Car Conversion Mess!

UPDATE!  If your looking for a solution to installing a decoder in the Tomix cleaning car, you could read my debacle below, which may help you.  Or you could click on this link for a pdf of the installation that is much easier, shorter, and probably safer! 

What a mess. So, I'm on my third Tomix Cleaning Car. I've already burnt out the motor on one so far (DO NOT PUT THESE ON A DCC LAYOUT WITHOUT A DECODER NO MATTER WHAT ANYONE SAYS) and decided I would try to do the DCC conversion on this myself. Its one little car, how hard can it be? Plus, if I screw this one up, I have another one to destroy. This'll be fun.

My approach to DCC conversions is to chicken out as much as possible. Sorry, but those of you looking for expert electronics advice or bundles of encouragement with decoder installs - stop reading. Now.

I like DCC for its operating experience, but hate all the hassle with getting the stupid, expensive clumps of wire and electronics to act like they are supposed to act. All those books about "DCC is simple!" are a bunch of rubbish. Its not even electronics in my mind, more like alchemy. At this point you should realize you should never take my advice on this decoder/install stuff. Seriously. Even if you come back in a year, and I did this crazy cool decoder install that is just amazing and I'm all, like, bragging about it? I'm lying. Don't believe a word. I'm an amateur and following my example will lead to certain failure and a romantic passion for plain old DC control and all that fun you had with the 'direction' switch seeing if you could make your GP9 do a wheelie.

So, now that my utter lack of credentials in this field is firmly established, I will now demonstrate my utter cluelessness with this lame attempt at a decoder install in a stupid cleaning car.

My absolutely shameful and cowardly approach for this decoder install was to take advantage of this circuit board produced by a German company, DigitalZentrale, that uses one of the few (theoretically) simple solutions for decoder installations: the NEM651 plug. In theory, that means most decoder installs should be truly 'plug and play' (in reality, we all know that's not true). Unfortunately, the actual manufacturers who use this standard only really applies to a small set of German manufacturers. So I guess for the rest of the world its "learn how to solder train-boy!".
But I have to hand it to the Germans...the NEM651 is a great idea in a hobby that saw its last creative days when it came up with 3-rail tinplate track. Anyway, I got the circuit board (above), complete with all German instructions (although its possible to get a barely intelligible English translation from Google, but its not that helpful), and started dissembling the track cleaning car.

I did 'cheat' and peak at the garbled translation (I noticed enough "ACHTUNGS!" and "NEINS!" in the German instructions to get the fact that the photos alone may not be conveying some important information).

Taking apart the Tomix cleaner was pretty easy, once you realize that you have to remove the screws from the trucks to remove the cover where the motor is (the instructions showed both sets of trucks being removed, but I don't really see the point of removing the trucks from the side of the car opposite the switch and motor....all there is on that side is just some weights.). In fact, while the photo below shows the correct placement of one Philips head screwdriver to remove said trucks, this is actually a pointless part of the process. But enjoy the photo anyway:
So, with both sets of trucks removed, a firm grip (with -as is usual at this point- more force than you think its wise to apply to these thin plastic shells) and lots of pulling gets the little plastic covers off. You can then have all sorts of fun dumping all the parts out on a table.
So here's a more than useless tip: Once those screws are removed, all the parts really don't just fall out. You'll need to remove that 'fan' thing (round black thing on bottom of car) from the 'pole' ("axle"? "rod"?"stick"? etc...) or whatever that 'pointy' thing is that comes out of the motor at the bottom. I hope you can tell what I am talking about from the above picture, otherwise I just wrote a sentence more confusing than Google's over-rated capability at translating German N scale websites (actually, the Japanese translations are worse, but more entertaining). Anyway, the 'pole thing' on my motor inserts into the hole on the 'fan' thing, and mine was on really tight, and when it finally came off - it flew across the room (of course, I'm not worried if I lose it, cause I have extra parts from the cleaning car that I already fried a motor on! Hah!). So be careful.

Now that all the important pieces are removed and scattered across your desk and you realize you don't really remember how they go back together, its fairly easy to see how this new NEM 651 circuit board will replace the existing circuit board. Did I say I love the NEM 651 format? Yes? Okay, I'll stop repeating myself.

As you can see from the photo below, the new and the old circuit boards. The new board, which has a fancy little NEM 651, 6-pin, Lenz Mini-Gold D ($44.00) decoder inserted into it, sits next to the old one! Right now I'm thinking "Hey! This was easy!"

Yep. Just keep thinking that.
Then came the panic. See, there's this round black thing that goes into the round hole on the original circuit board. At the time, I don't really know what this round plastic thing does and I don't care, all I know is that the 'round black thing' (which also had little metal pieces on it to pick up electrical current! Oh no! Its important! Arg!) WILL NOT FIT IN THE OBLONG HOLE ON THE NEW CIRCUIT BOARD!!! I've been had! Of all the cruddy luck! To get this far, only to find out that I got a circuit board for some other model Tomix cleaning car, this really su.....wait....what's that? The round thing connects to the switch on the top of the Tomix car that turns it on, off, and to CL mode (CL mode, for those of you who don't visit the Japanese train forum and aren't versed in the world of Tomix, is a "Constant Lighting" mode that Tomix came up with so that the lights on Japanese trains always stay on under traditional DC power, or so I think. Its also rumored to be a problem for my Japanese modelling friends in their attempts to convert their Shinkansens and Thomas's to DCC, but that's another story....)?

So I start thinking....if I'm adding a decoder to turn this thing off and on, I probably don't need the "round black thing with the electrical contacts which won't fit in the oblong hole on the new circuit board". So I ignore it and move on. More fun awaits.

Unfortunately, just plugging the decoder into the NEM 651 socket isn't enough, according to the instructions and the design of the cleaning car, you need to bend the pins on the decoder so that they go at a right angle right about where the circuit board ends. With this bend in the decoder, it will neatly rest within a pocket between the weights that surround the motor and the plastic shell (or you could cut a hole in the shell and have it stick out, which will turn out, for me, to have been a better choice). So, bending six tiny little pins shouldn't be all that hard, right?

And its a really good thing I have this handy Google translation tool, because the instructions actually mention "Lenz" in this section (one word I can pick out of the sea of German), so I know I have a Lenz decoder, and I know this is important. So skipping past the original German and going to Google, here's what the translation tells me:
The legs of Lenz decoders can not bend to these break off, they see
bitte davon ab einen solchen Decoder zu verwenden. Please use them from such a decoder.
Whew! Good thing I read that! What was it? Something about 'leg's breaking off' of Lenz decoders? No problem! I get the pliers out and quickly proceed to....break the legs off the decoder! ARGGGGGGGGG! (Do you hear that sound? Have you heard that sound before? Its the sound of a decoder going to decoder heaven).

Plan B

Reminding myself that there's something redeeming about this hobby, that money isn't everything, and that this is still a better way to spend my time than watching TV, I figure out a Plan B. I decide to use one of the Digitrax DZ125 decoders I have hanging around! I am determined to get this job done and start cleaning some track with DCC control! Also, the price is great on these Digitrax decoders too ($20-$25?), so I'm not as worried about....okay, not going there...it will all be fine. Really.

Here's my plan of attack. You only need two wires, I guess. That's what I'm down to. Guessing. Two wires for the motor...that's all you need, how hard can it be? I religiously check the Digitrax instructions to confirm that the Orange and Grey wires are the only two wires I care about.

This is so easy! I should have done this first!

So I strip down the wires, tin them up a bit with my soldering iron (they need to be a little stiff to fit inside the socket) and jam in their respective holes. See photo below.
I think to myself...is there ANY REASON this cannot work? I tell myself "No, there's not! I mean, this is just a DCC decoder installation! Its not rocket science!"......

Moving along....

Put the cleaning car back together. I notice that the new circuit board doesn't sit quite as tightly between the contacts on the motor as the original curcuit board. Also, make sure you put the circuit board in 'shiny side down' (see, that's the kind of decoder installations I can understand! "Shiny side down", or "Plug thing #1 into hole #1"...THAT I can handle! Since when did model railroading become electrical engineering? Some day I should write a post about the electrical diagram I got that was supposed to help me add LED's to a control panel. There were so many weird shapes and squiggly lines...come on, just tell me the "red and black wires" go {And to make even THAT difficult, apparantly, the 'black wires' aren't shown because they are 'common', well PHOOEY! Show 'em anyway! Why are electricians so lazy about this stuff} ! I tell my son that he should go to college and major in electrical engineering if he wants to play with trains like his dad when he gets older). So, the new circuit board is not quite as tight, but it fits, and the whole thing gets reassembled.

With everything back together, I make my way to my old Windows XP PC with JMRI and Sprog II to check out my install and program this bad boy! I also discover that I'm under the illusion that, at least in this hobby, buying more junk will make problems go away. You see, and I've mentioned this before, I wasn't happy with how difficult it was to program decoders with the Trix Mobile Station...the Sprog II looked like a great solution, so i spent more money. In all fairness, its been a lot easier, the problem is you get NEW problems! So its almost like your back at square one!

With everything set to go, I hit the fateful "read decoder" button in the Decoder Pro program and .... I get this:

Error 306 — timeout talking to command station
Fantastic. I end up rebooting, reinstalling, tinkering with COM ports in preferences, updating drivers...you know, all that fun stuff I like to do that got me into this hobby in the first place.

Eventually, after a couple of reboots, I get
Error 308 — No acknowledge from locomotive
That's it. I'm done. Okay, not really. I actually take it apart, check connections, curse the looser circuit board connection, fiddle with stuff, etc... But, like that great Jerry Seinfeld joke " I don't know why I look under the hood of my car when its not working....if there's not a giant switch turned to 'off' under the hood, I'm useless" pretty much sums it up.

So, where am I now? Despair. Disgust. And one fried cleaning car, one broken decoder....and still lot's of dirty track.

Don't worry, the saga will go on. I expect there will be a "Plan C" once I can muster up the courage. I refuse to admit defeat (I'm not that smart). Apologies to all N Scalers, 3-Railers, Germans, Japanese, DCC'ers, Tomix, Digitrax, Trix, JMRI, Sprog, Lenz, electricians and electrical engineers who were offended by this post. I'll do better on my next one. I promise.


  1. Model railroading has always been a branch of electrical engineering :P

    Anyway, I've fried about twice as many decoders as I've successfully installed. I manage about one successful installation a year. I have blown three, count 'em: Three, decoders trying to get my Tomix EF81 converted, and I am awaiting my fourth. I went through three on my Tomix DE10 before I decided to switch from a Digitrax DZ125 (at least one of which was defective out of the box) to a TCS decoder, which I have yet to order. I even fried one of my Kato FL12 "drop-in" decoders trying to install it! Most people don't dry decoders that take zero effort to install correctly!

    I haven't converted my Tomix cleaning car yet; I just clean on DC. But when I do, I'll be using this same device that you have.

    That said, your problem is an easy one: You just need to insert the red and black wires too! Otherwise, your decoder isn't getting any power, and isn't connected to your DCC system!

  2. Arggg!!!! That was stupid of me! I was just looking at the new circuit board and only saw the two copper strips that went to the motor so ignored other possible connections! I'll try that out.

    In related news...I couldn't wait to clean my track any longer, so switched out my DCC connections with a traditional DC system! That was a much easier way to get my job done!

  3. Check out the underside: You can see that the two middle traces connect to those honking huge pads straddling the NEM socket :D

  4. Oh, and don't wire it up backwards, or else your vacuum will end up a blower! (The original circuit board had a bridge rectifier so the motor would only ever spin in one direction; doesn't look like your new board has that.)

  5. Well, so? Don't leave us hanging!

  6. Thanks a lot to share your job with the Tomix cleaning car, it was really useful. I didn't know where to start from.... I made my cleaning car dcc conversion without problems thanks to your warnings!!


  7. Thanks Dani! I like to share my mistakes so that others can learn from them! I'm glad this was helpful!

  8. Jerry, My Tomix cleaning car just died. Again!!!!! My
    2nd one so far.

  9. Hi Mustafa! Oh no! Sorry to hear that! I have only fried one so far, but the reason its probably only been just one, is because I seldom use my Tomix car for cleaning!