Tomix 400 Shinkansen DCC Install

[mrpig]

Hi All, long time no post.

 

Well, I think Tomix invented a new category with this one. Every knows about standard chassis and DCC friendly. This one is DCC hostile, it sat on the bench in pieces for nearly 3 years before I decided to stop putting it off. I spent about 7 hours over the course of 3 days on this one. Half of it was probably procrastinating because this is the first install I have not enjoyed.

 

If graphic images of open heart circuit board surgery make you squeamish, click away now.

 

Photo 1

Let’s get into it. If you spread the shell at the rear of the plough assembly, the plough can be removed starting at the rear. Be careful with the nose coupler as there is a small contact strip for disabling the lights when coupled to an E2 or E4. The contact strip is removed for this install but you may want it later if you ever want to go back to DC. I still don’t know where mine is after it flew across the room. Also watch out for 2 springs on the motor contacts, we don’t need anymore, so put them in the parts box.

 

Photo 2

This is the top of the cct board. I forgot to take a before photo, so I coloured in the tracks to make them more obvious. There are 3 through plated holes connecting tracks top and bottom. Drill out the marked hole on just enough so there is no continuity between the 2 tracks it connects. We need to solder to the pad on top, so be careful with the drill.

 

Photo 3

Use the seat assembly to line with the chassis to work out where to drill these 2 holes. They need to be just forward of the spring posts on the motor carrier, but not too far or the wire will rub on the flywheel. It’s much easier to see with all the bits in your hands. Thouroughly deburr the holes as ther will be wires folded hard against the edges on the top of the board.

 

 

Photo 4

Overall shot of the board showing the various cuts in the tracks and pads where the paint needs to be removed for soldering. Notice the long track at the bottom of the photo gets split in two so only the motor wires need to be fed up the centre. Close-ups later.

[mrpig]

Photo 5

Now it’s time to dremel out the bottom of the seats to make room for the wires. Notice also the hole near the back. It needs to be big enough for 5 wires. The 2 power wires will come through the existing holes for the interior lighting pickups.

 

Photo 6

Keep holding the seat assembly up to the light and you will get a feel for how much material can be removed.  Mine is quite thin and the pic doesn’t really show it that well. If I was to do it again I would use magnet wire.

 

Photo 7

Before installing the 3 wire links, make sure all the cuts are clean through the tracks. Use a meter to be certain. Try to keep the links in roughly these positions to minimise dremeling of the seat assembly.

 

Photo 8

Dremel out the light pockets to provide clearance for the wire links. The cct board needs to sit in the bottom of the seat assembly with no pressure on it.

[mrpig]

Photo 9

Before doing any soldering, I tested my handy work using a 9V battery with a battery clip on it. Hold the +ve lead on the pad where the blue wire is.  –ve to the white wire’s pad will light up the white led and –ve to the yellow wire’s pad will light up the red led. Remember to thread the wires through the seat assembly first making sure the red and black go through the correct holes so there is no cross over when assembled.

 

Pass the orange & grey wires through the hole with the lighting wires, then down through the 2 holes we drilled earlier in the middle area of the board. Orange on the right and grey on the left. I forgot to take a photo of this part.

 

Photo 10

In this photo you can see the 2 spring posts I talked about back near the start. These posts might need trimming if they get in the way of the wires. Pop the motor out of the carrier before doing any soldering here.  If you have an adjustable iron, turn the heat right up so you can be fast. This is the most awkward part of the install to solder. Use the finest tip you have and file it even finer, about .5mm to .7mm is ideal. Solder the wires on the inside of the contacts so they clear the posts when the motor is back in the carrier. Again, make sure the wires don’t cross over.

 

Photo 11

Now you can clip it all back together, carefully pulling wires through holes as you go. Can’t see it properly in the photo, but even with all the dremeling, the wires put a bit of pressure on the back end of the seat assembly giving a noticeable bulge. Definitely wish I had some magnet wire before starting this.

 

Photo 12

The finished product ready for testing before final assembly. I used a TCS Z2, but a DZ125 or M1 should fit just as well. That stock settings on the Z2 let it move so slow that it is boring. Don’t forget to put the coupler back in before putting the shell on.

 

Glad I finally got it done, but not sure if I would do it again.

Looks similar to Bernard's E3 except this one has a one piece chassis.

 

I wish Tomix would think outside of the DC square.

[CaptOblivious]

Really outstanding work you've done here! Thank you for the clear and detailed write-up!

[mrpig]

Wow, I really wish I had of seen Bernard's E3 before I tackled this. Would have spent a lot less time doing mental gymnastics  :BangHead:

[mrpig]

Thanks Capt, next is the other end. Already done, just have to write it up. Lots easier.

 

One thing I have noticed is that the light pipe design for the tail lights is not that great. One of the red lights is very dim. Same on both ends of the train and no difference between DCC or pre-decoder. I almost thought I had gotten something wrong until I checked the tail end before starting work on it.

[The_Ghan]

mrpig,

 

You get my "Post of the Month" award for this one.  I'm going to need to cut and paste your whole thread as I've got the 400 and E3 to DCC later this year.  They scare the willies out of me.

 

Thanks for the timely update.

 

Cheers

 

The_Ghan

[mrpig]

The_Ghan, lol, thats why it sat for nearly three years. Grinding metal and plastic away doesn't phase me, it just made my brain ache every time I looked at it. I had to re-assemble it before I started because I'd forgotten how it went together. If I was a really nice bloke, I'd tell you to post it to Adelaide, but there is now way I'm going through that again. Glad I bought the Kato E3.

[mrpig]

Here is the cab car at the other end. I used a TCS FL4.

Entry is gained by unscrewing the trucks once the shell is off.

 

Photo 13

These are the cuts needed in the lighting board and the solder pads I created. The cut at the red mark is not required. It was just convenient to go from edge to edge. Also, the small pad near the red mark isn’t a pad, it’s a slip of the dremel.

 

Photo 14

Bring the wires up from the bottom and install a small link as shown. The light pocket may need dremeling to clear the link.

 

Photo 15

You need to file a notch in each of the contact bars to provide extra clearance for the wires.

 

Photo 16

Here is everything mostly back in place. It looks like there is plenty of room without the notches we filed, but without them, the wires won’t get down into the well in the chassis without being pinched. You also need a wrap of kapton tape to keep the contacts on the light board insulated. Normally I remove the contacts, but they are needed in this case to hold up the rear of the light board.

[mrpig]

Photo 17

Everything tapeed up to make re-assembly easy ( the locating pins for the contact bars are on the seat base. Not the chassis as is normal ). Since there is so much room in the well, I left the unused function wires in place just in case. I have had one go bad before and had to attach new wires to the spare functions because I’d cut them off.

 

Photo 18

Side view gives a better idea of where the tape needs to go to insulate the contacts.

 

Photo 19

Just needs all the excess tape cut off and it’s good to go.

 

Pity the other end wasn’t this simple.

I really don’t like the combined motor/cab car concept.

[mrpig]

Ghan, I could email it to you as a word doc if you like. It's only 1.3MB

[Martijn Meerts]

The problem with DCC friendly is that even that often is a pain. For example, Kato's DCC Ready trains are only DCC ready if you're willing to use Kato's limited functionality decoders. Use any other decoder, and you'll still be soldering, milling, cutting and drilling.

 

Many of the European trains with NEM pockets have such low quality sockets, that you still end up soldering in the decoder (granted, it's real easy to get them in..) Some trains have NEM pockets that are situated so strange, it doesn't fit most decoders at all.

 

One of the people at the hobby store in Germany I visit from time to time has a HUGE collection of DCC equipped trains (probably talking 200+ trains), and he's actually gone and soldered in all decoders, even when trains had NEM pockets. According to him, the sockets are just not reliable enough.

[The_Ghan]

Ghan, I could email it to you as a word doc if you like. It's only 1.3MB

 

I didn't know you were in Adelaide ... I'm tempted to hand deliver the beast to you myself !!!

 

An email of the word doc would be tops, especially if you have the images as well.  Just bundle the whole shebang up and email it to me.

 

Cheers

 

The_Ghan

[The_Ghan]

Just a general comment about using different decoders in cab cars: someone once posted that the Digitrax TF4 doesn't support directional FOF and FOR lighting.  I read this, of course, after ordering 20 of the damn things.  I've had an opportunity to review the documentation which, on the last page, shows the TF4 being wired up for transponding and FOF and FOR lighting in lieu of the pre-installed motor decoder.  So, if the TF4 does not support the directional lighting, why would they show this.

 

Can anyone confirm?

 

Cheers

 

The_Ghan

[CaptOblivious]

Just a general comment about using different decoders in cab cars: someone once posted that the Digitrax TF4 doesn't support directional FOF and FOR lighting.  I read this, of course, after ordering 20 of the damn things.  I've had an opportunity to review the documentation which, on the last page, shows the TF4 being wired up for transponding and FOF and FOR lighting in lieu of the pre-installed motor decoder.  So, if the TF4 does not support the directional lighting, why would they show this.

 

Can anyone confirm?

 

Cheers

 

The_Ghan

 

That was me you heard it from, and it came directly from a Digitrax tech rep. Here's what they said, and I quote: "The outputs of the TF decoders are not directional." This is reinforced by the manual, which allows you to assign a lead to F0, but has no way of assigning directionality to the lead (that is, on in one direction off in the other), or assigning leads to F0f or F0r (the conventional way of specifying directionality for the F0 function).

[Bernard]

Wow, Mr Pig - How did I miss this post! Excellent work and great photo by photo description of the install. Yeah there is a lot of mental anguish before doing this type of install and it's one of those trains that after you do it you don't want to have to open it up again.  :confused5: 

 

And to The Ghan - Good Luck and may The Force be with you on this install! 

[KenS]

The problem with DCC friendly is that even that often is a pain. For example, Kato's DCC Ready trains are only DCC ready if you're willing to use Kato's limited functionality decoders. Use any other decoder, and you'll still be soldering, milling, cutting and drilling.

 

And on at least some of the older trains, the decoders didn't seat against the contacts properly, and needed to be shimmed or moved a millimeter (literially) in order to work properly. I have one commuter train that Just. Won't. Work. (I'm considering doing a wire-in conversion).

 

I like being able to see the passenger compartment unobstructed.  But oh how I wish for a standard decoder socket!

[Bernard]

 

I like being able to see the passenger compartment unobstructed.  But oh how I wish for a standard decoder socket!

 

I agree.....not an easy task on the "Super View" train with it's extra wide windows.

[Martijn Meerts]

They're working on a new standard for decoder sockets which should solve the bad connection problem. It's also a bit more universal and future proof. It also looks like it needs more space though, so it might not really be optimal for N-scale .. We'll see once it's close to being available though.

[KenS]

What's really needed is use of the NMRA "small" 6-pin socket (aka NEM651).  Per RP 9.1.1 (PDF) it can handle both a motor and two lights (although I don't see how the common would work) so it would work for both cab and motor decoders.  You'd likely need a separate decoder for interior lighting, but I think Kato's current approach of making that part of the lightboard is actually the best solution for that need.

 

But the current trend seems to be to right-angle connectors (like the 21MTC) rather than end-on ones, which take up too much space for N-scale "in the floor" installations and provide lots of contacts. Nice if you're doing HO with sound and operable couplers or something, but not what we need for fixed-consist trains. And the PluX8 8-pin connector appears by its description to be only a right-angle one also.

 

What we really need is a six-pin connector designed to be attached to the car frame, rather than a circuit board, that takes an end-on circuit board no wider than about 10mm.  The NMRA "small" could be used that way, I think, but I've never seen it done.

 

Martijn, do you have a link to anything about the new standard?  Is this NMRA, or MOROP (the "NEM" folks), or someone else?

[Martijn Meerts]

I've really started disliking the current NEM651 sockets, quite often the decoder just doesn't fit well, and the connection is really flaky ...

 

 

Ken, there's some info at http://www.digital-plus.de/e/digitalplus-decoder-silver.php (bottom of the page).. Looks like Lenz has a big part in it, so it'll likely be a standard that'll be popular in Europe at least.

[mrpig]

Martijn - Yes I agree with you on the Kato decoders. I used their cab decoders in an N700 when I first started, every time I put the thing on the rails I had headlight problems. Those FR12's are now wired and soldered.

 

Ghan - I think TCS is streets ahead of Digitrax when it comes to lighting. If you do the "Rule 17" thing, TCS allows you to adjust the amount of dimming. I have also read that if you want to do alternating ditch lights on US diesels using led's instead of bulbs, TCS is the way to go. The article said Digitrax just can't do led ditch lights properly. I can verify that statement as I did it with a C44W and they get out of sequence. Haven't tried it with a TCS decoder yet though, might have to just set one up on the bench to try it out.

 

The email icon won't let me send an attachment so I'll try it here.

[mrpig]

That works, just had to split it in 2 to stay under the 1MB per post limit.

[The_Ghan]

Got it, thanks mrpig.

 

Cheers

 

The_Ghan

[The_Ghan]

Ah Cap'n,

 

Thanks.  I remember all of that now ... about a year ago.

 

Cheers

 

The_Ghan