Need Help with a Draft: Open Letter to DCC Manufacturers

[CaptOblivious]

All,

 

I'm currently drafting an open letter to DCC manufactures. As we here know all too well, there is quite a mismatch between Japanese trains and American/European DCC decoders. While I don't think we could convince, e.g. Tomix to change their DCC-unfriendly ways, we might could convince one or more decoder manufacturers to develop products that cater to the specific needs of Japanese modelers.

 

To that end, I've begun drafting a letter, to post here, to my website, and to mail to various manufacturers. Before I post that draft here, I'd like to know:

 

1) What problems do you face, as an installer/converter, that are unique to Japanese trains?

2) What would you like to see in a decoder?

3) Would you be willing to consider signing such a letter, and posting it to your website? (I don't expect commitment until you've actually seen the letter, of course).

 

The next post will contain the current (sparse) draft of the letter so far. Editing and comments welcome!!

[CaptOblivious]

I've been thinking a lot lately about the state of DCC re: Japanese models. A combination of two factors makes life difficult for the North American modeler of Japanese prototype who has an interest in DCC. The first factor is this: Japanese model companies (typically) do not design their models with DCC in mind. The second factor is this: Western manufacturers of DCC products (typically) do not design their products with Japanese models in mind.

 

While little can be done about the first factor, perhaps something can be done about the second. Hence this letter. This letter is in three parts. The first describes the current state of Japanese model locomotives. The second describes the current state of Japanese MUs. The third and final section is a list of features and products that would go a long way to mitigating the first factor mentioned above. Nothing called for is beyond the capabilities of today's technology; Indeed, much of what is called for is a simplification of products already available.

 

Locomotives

 

Japanese locomotive models are almost universally not DCC-friendly, with the notable exception of recent Kato products.

 

Kato

 

Currently, all Kato-designed locomotives are designed to take a drop-in decoder, usually a Digitrax DN163K0a, but sometimes the DN163K1D. Kato is the Japanese importer of Digitrax products, so it's no surprise that their models are designed around these decoders. However, simple as installation should be, often the LEDs on each end of the decoder must be removed and shortened before the decoder will fit in the locomotive frame.

 

 

Tomix, Micro Ace, &c.

 

Tomix and Micro Ace locomotives are not designed with DCC in mind. They do use split-frame design, which means conversion is relatively easy—in theory. The frames typically take up all the free space inside the locomotive shell, and so conversion requires significant frame-milling. Indeed, the layout of the internals often doesn't leave enough space in the frame to mill a large-enough chunk to fit a decoder. This is the problem I encountered with my Tomix EF81. One common solution is to sacrifice one of the lightboards, using its space for a decoder instead. Often there is only just barely room for this kind of install.

 

Currently, TCS makes a decoder, the CN-GP that is designed to replace existing lightboards in American locomotive models, but because space is so tight in Japanese models, the CN-GP still requires frame-milling to make it fit.

 

Multiple-Units

 

Proportionately fewer trains in Japan are locomotive-hauled than elsewhere in the world. Most trains are multiple-units (MUs). MUs present a particular challenge for DCC conversion. One reason is that motive and lighting functions are not located in one locomotive, but distributed across several cars. Minimally, there will be two cab cars, each with directional headlights and taillights, and a separate motor car that provides motive power for the model. This means three separate decoders for one train! Using standard wired decoders, this can get very expensive.

 

Another reason MUs present a particular challenge is space. MUs are passenger cars, and Japanese model manufacturers take pride in carefully modeling the interior space, including in the motorized cars. The motors used are small, and embedded in slight frames located in the car's undercarriage, leaving the passenger compartment (mostly) empty. Having a decoder show through the windows is undesirable. But where else to put it?

 

Kato

 

Kato's recent MU models are designed to use a special line of decoders designed by Digitrax. These decoders are very small, and are hidden in special nooks in the undercarriages of the cars that take them, hiding them from view—a very nice feature indeed. The EM13 is installed in the motor car, and only provides motor outputs. The FL12 is installed in the cab cars at the end, and have just two directional lighting functions for the headlights and taillights. Finally, the FR11 is designed to fit with Kato's passenger car interior lighting kits, and offer just one function for controlling the interior lights. While a great idea, these decoders are rather limited. They only support 2-digit addressing, which is a terrible shortcoming. And although they offer Digitrax's proprietary Transponding feature, taking advantage of Transponding is nearly impossible on a temporary floor layout (which is how most model-railroading is accomplished in ever-cramped Japan, and how many of us enjoy this hobby in the western world). Moreover, and somewhat frustratingly, they do not offer CV read-back, even on the programming track. Indeed, they send no acknowledgement at all, so it is very difficult to tell a good decoder from a bad—in service move, they all appear to be broken.

 

Kato's older models, many of which are still in production, do not take these decoders, and so suffer from the same shortcomings as the Tomix and Micro Ace models described next.

 

Tomix and Micro Ace

 

As with their locomotives, neither Tomix nor Micro Ace make any provision for fitting decoders to the MU models. The result is that decoders typically must be installed where you can see them through the passenger windows. Moreover, the selection of function-only decoders on the market is underwhelming, and the selection of motor-only decoders is non-existent. For proper operation in the cab-cars, the decoders must offer directional function outputs; none of Digitrax's function-only decoder will do this. And the very limited amount of space in the MU requires very small decoders generally. Many N-scale decoders simply will not fit in the interior space available.

 

Too, proper installation of a function decoder in the cab cars requires dismantling the lighting circuit to isolate the headlights from the taillights. However, this isn't always possible. To solve this problem, NGDCC, a Japanese DCC manufacturer (who doesn't export outside Japan!) makes a decoder that power two functions using just two leads, so that you don't have to modify the lightboard. When the train is moving forward, the leads provide +12V; when the train is reversed, they provide -12V. This is a nice touch.

 

Desiderata

 

What do we want from our decoders?

[Guest ___]

DCC is too much of an additional headache to bother with, hence why I never bothered to go to it for the HO stuff. If I were to ever do N-scale J-train DCC, I'd want, I want PnP or RTR

[Martijn Meerts]

Another option would be to try and design drop-in boards. With an etching tank and some research it should be doable.

 

The drop-in boards could even be designed to have a little socket which the decoders plug into, that way people could use their own preferred decoder.

 

The drop-in boards could easily be sold on e-bay or something.

[CaptOblivious]

Another option would be to try and design drop-in boards. With an etching tank and some research it should be doable.

 

The drop-in boards could even be designed to have a little socket which the decoders plug into, that way people could use their own preferred decoder.

 

The drop-in boards could easily be sold on e-bay or something.

 

To be honest, I'm not sure that I see how this would work, except with Kato locos—which are designed for drop-in boards. If this were possible in general for split-frame locos, the market would already have quite a few offerings for older American models. But, alas, there are not. The closest thing to a drop-in board for split-frame locos is TCS's CN-series (link above). But even these, as I'm finding, are not ideally suited to Japanese models, because of differences in the lightboard mountings between American and Japanese models.

 

But, if you're talking about MUs, then I'm all ears…

[Martijn Meerts]

Lightboards and MU boards would be possible to design one way or another. I guess with regards to split frame locomotives, it's really up to Kato, Tomix, MicroAce etc. to make the decision to make them DCC friendly.

 

I mentioned earlier about this idea I had to buy an etching tank and some components. My biggest interest would be to design light strips for MU's that can be easily installed, and have a very simple decoder built-in. The problem is that that requires an IC to be programmed to accept DCC signals and convert them. A similar thing could be done for light boards and full MU board replacements.

[Bernard]

I really like this letter and yes I would sign it when it's finished. I'm not as technically minded as other modelers but there are problems with these manufactures and their trains when it comes to decoder installs.

 

What would you say to showing this draft to some of the decoder manufacturers like Digitrax and TCS illustrating all the problems their customers are having installing decoders in these trains.

 

The recent post by Mrpig shows in detail all the work required to properly install a decoder in a Tomix train.

As a results some modelers who run DCC shy away from certain manufacturers like Tomix because all the problems they have with installing decoders in their products not to mention all the returns to decoder manufacturers because of these failed installs.  

 

If you want people to buy your product, make it so that decoder installs are fun, confidence builders and easy to do. People will buy more of your trains if you can accomplish this rather than avoid them at all costs.

[CaptOblivious]

I really like this letter and yes I would sign it when it's finished. I'm not as technically minded as other modelers but there are problems with these manufactures and their trains when it comes to decoder installs.

 

What would you say to showing this draft to some of the decoder manufacturers like Digitrax and TCS illustrating all the problems their customers are having installing decoders in these trains.

 

The recent post by Mrpig shows in detail all the work required to properly install a decoder in a Tomix train.

As a results some modelers who run DCC shy away from certain manufacturers like Tomix because all the problems they have with installing decoders in their products not to mention all the returns to decoder manufacturers because of these failed installs.  

 

If you want people to buy your product, make it so that decoder installs are fun, confidence builders and easy to do. People will buy more of your trains if you can accomplish this rather than avoid them at all costs.

 

As this letter is for Digitrax, TCS, etc, no point in showing them a draft ;) They'll be sent the final product. What I would like out of it is a demonstration that there are still areas for real innovation in decoder design, and at least a burgeoning market for those designs. There's not a whole lot we can do to convince the Japanese model makers to make installs easier, but there is, I think, still more that can be done on the decoder side to make them, if not easier, then at least cheaper.

 

Sadly, this means that sometimes, if we want the cleanest, least visible install, even if we had products that catered to our specific needs, sometimes we're gonna have to pull out the milling machine and mrpig's pictorials to do the job right. And the manufacturers are very clearly doing a lot right already (e.g., very generous warranties for fried decoders).

 

But here's what it boils down to for me: I want a version of the Kato EM13 with 4-digit addressing, advanced acceleration and deceleration functions, and RailCom. But no-one is going to make it unless we tell them lots of us want that  ;D

 

But, ultimately, I think that this market is too small to support the tooling costs; moreover, there are just too many different designs to account for. I don't know that such a letter will have much impact, but I hope it has some. I think that ultimately, Martijn's got the right tack: Small batches of highly-specialized decoders. So, it seems to me, there are some requests it is reasonable to make from manufacturers, but that in the end, we're going to have to take care of ourselves.

 

Sadly, I've just learned that my soldering skills are not what I thought they were. So that means (for now) I'm pretty much at others' mercy…

[railzilla]

The problem with teh Kato decoders is that they are very hard to get. Seems Digitrax cannot sell them directly but only does manufacturing for KATO.

 

What i really would like is a interrior lighting with LEDs and a decoder already built in in one piece. So there would no need to have a decoder and a light board.

 

For older stock a small decoder would be the choice. It also has to be thin, with only one side equipped with components. If its really thin it would be possible to squeeze it between the split frames, in thise case as a trade of the length can be a bit longer. For headlight an option would be nice to either set two outputs as single outputs with a common ground or a bidirectional output. Some ICs can do this with a so called H-Bridge.

 

Another thing which i was thinking about is why not build a motor with a built in decoder. So just the motor has to be changed with no milling at all and the decoder can fit the motor perfecly. It would even be possible to use brushless motors.

[Martijn Meerts]

Considering how small the market share is for Japanese trains outside of Japan, and how small the market share is for DCC in Japan, I'm afraid we'll have to solve our own problems.

 

The letter might convince some manufacturers to make smaller function decoders at least, because most of the current ones are way too big to be of any use. The smallest ones I've found are Uhlenbrock decoders, which aren't the easiest to get, especially not outside Germany.

[mrpig]

I love railzilla's idea for interior lighting with a built in decoder so all the lights can be turned off when the train is being stored in a yard. Instead of isolating power to that particular track. I splurged on the Kato N700 and installed all the Kato decoders and lighting. Man that is one expensive puppy. Just as well it is only a half length train

 

I think it will be a long time before Tomix and MicroAce start making dcc friendly chassis, so we are stuck with hard wiring. You should see the new Tomix 400. The lead car has the motor and they have made a full length pcb that has all the contact points and lights. To make it worse, the pcb is full thickness as well. I have been looking at this for 2 days now and I think I am just going to have to settle for visible wires.

 

Definitely would like to see smaller motor only decoders. Same for function only decoders with maybe only 3 functions max but including the Lenz idea where white & yellow both work on F0 and can swap polarity. If Digitrax did this I would probably swap out all my lead cars to enable exact position station stops. Then I could model a subway station that has the doors that line up with the train's doors. Then I'd have to buy more mu's to use the function decoders removed from the lead cars. ;D  I think I'm developing a habit  ;)

 

Another feature I would like is to be able to program speed and momentum in the function only decoders. This is so the head/tail lights swap at the right time when I get lazy and hit the direction change button while the train is still moving. Completely unprototypical but I'm sure I am not the only who has done this.

 

And finally, fix those Kato decoders to have 4 digit addressing and readback.

 

ooohh.......... and make some function decoders that include the led resistors so we have a choice. Wishful thinking  ::)

[Martijn Meerts]

There are people who offer lighting strips with very basic decoder built into the board. Of course, none of those fit in Japanese models.

 

They're not difficult to design and build, just requires an initial investment for an etching tank and PIC programmer really, and of course lots of time learning how to program the PIC to accept DCC commands ;)

[mrpig]

That is something I really want to do. Learn to program pic's and avr's. So many things, so little time.

[alpineaustralia]

Capt, can you explain your statement:

 

For proper operation in the cab-cars, the decoders must offer directional function outputs; none of Digitrax's function-only decoder will do this.

 

I thought the Digitrax TF4 did allow for directional headlighting.

[CaptOblivious]

Capt, can you explain your statement:

 

For proper operation in the cab-cars, the decoders must offer directional function outputs; none of Digitrax's function-only decoder will do this.

 

I thought the Digitrax TF4 did allow for directional headlighting.

 

 

Nope! I thought so too, and was about to buy one when I noticed the manual didn't say how to set up directional lighting. An email to Digitrax confirmed the bad news; The TF4 does not support directional lighting! How awful for us!

[alpineaustralia]

I thought you could do that by:

 

1. connecting white to headlights, yellow to tail lights and blue as the common

2. setting CV 64 to 00 and CV61 to 00 (ie to operate using F0)

3. setting CV 49 to 00 and CV 50 to 00 (ie. to operate as on/off).

 

The diagram on the back of the manual seems to imply forward light (F0 FWD) white and reverse light (F0 REV) Yellow

[CaptOblivious]

I thought you could do that by:

 

1. connecting white to headlights, yellow to tail lights and blue as the common

2. setting CV 64 to 00 and CV61 to 00 (ie to operate using F0)

3. setting CV 49 to 00 and CV 50 to 00 (ie. to operate as on/off).

 

The diagram on the back of the manual seems to imply forward light (F0 FWD) white and reverse light (F0 REV) Yellow

 

You can't actually set white to F0F and yellow to F0R. You can only set white to F0—not F0F or F0R but F0 full stop—i.e. non-directional! There is no way to program the functions to be directionally activated.

Also, it doesn't do Ops-mode programming.  >:(

 

There is a diagram in the manual that mentions F0F and F0R, but this is apparently an oversight that is at odds with both the rest of the manual and my email discussion with Digitrax tech support. Cf. my comments elsewhere about how horrible Digitrax documentation really is.

 

http://digitrax.com/ftp/tf4.pdf

[alpineaustralia]

There is a diagram in the manual that mentions F0F and F0R, but this is apparently an oversight that is at odds with both the rest of the manual and my email discussion with Digitrax tech support. Cf. my comments elsewhere about how horrible Digitrax documentation really is.

 

That sucks badly! I bought a whole bunch of them on the understanding that you could set them up as directional headlight/taillight decoders. I may need to send a letter asking to return them and requesting my money back!

[CaptOblivious]

There is a diagram in the manual that mentions F0F and F0R, but this is apparently an oversight that is at odds with both the rest of the manual and my email discussion with Digitrax tech support. Cf. my comments elsewhere about how horrible Digitrax documentation really is.

 

That sucks badly! I bought a whole bunch of them on the understanding that you could set them up as directional headlight/taillight decoders. I may need to send a letter asking to return them and requesting my money back!

 

Oh my.

 

So I'm guessing the number one thing people want is a simple two- or three-function only decoder? WIth directional lighting, and maybe one of those cool polarity-switching circuits?

[Martijn Meerts]

They already exist.. Uhlenbrock 73900, "function mini". I use them in the end cars of my 800 series, and plan to use them in all other end cars as well.

[Guest ___]

I second drop in decoders.

[CaptOblivious]

They already exist.. Uhlenbrock 73900, "function mini". I use them in the end cars of my 800 series, and plan to use them in all other end cars as well.

 

Could you say more about this decoder? I am having trouble finding a manual, even in German. Will it drive a bi-polar circuit like the Lenz does?

[Martijn Meerts]

Not sure about all the features, but I know it does directional lighting and it's small enough to fit in most end cars without modifying them ;)

 

Here's a link to the English manual: http://www.uhlenbrock.de/germany/Download/1/English/I96EEA64-01E.apd/Bes73900e.pdf