Help with my first-ever wired decoder install (Tomix EF510)

[spacecadet]

Hi guys,

 

I'm in the process of making the jump to DCC. Bought myself an NCE starter set and tested it out with the one DCC loco I currently have (actually an HO BLI GG1). I need to convert all of my current Japanese stuff. I'm not all that afraid of doing it and I like a good long-term project, but even after reading a bunch of stuff, I'm kind of stuck on my first install.

 

I'm doing my Tomix EF510 first for what I thought at the time were some well-considered reasons. I bought a Digitrax DZ126T decoder because it's really small. I see a place in the frame where I can mill and mount the decoder itself, but there are a few other things I can't figure out. Sorry if these are really dumb questions.

 

1) The light boards are upside down and the frame is shaped to both give them power and mounting stability. If I turn them right side up so they're not in contact with the frame, the light's just going to go everywhere and the retaining clips won't fit. But if I leave them upside down, they'll still be in electrical contact with the frame. If I remove the metal they're in contact with, they won't mount properly. Any advice on this?

 

 

2) The two halves of the frame are held apart about 1-2mm by some "+" shaped tabs in the clips holding the motor gears (you can also see that in the pics above). It looks like I should be able to route the motor wires right down through that gap, but I always see people talking about drilling holes or cutting channels around the motor instead. Can I just drop my motor wires straight in through that gap and solder them to the top of the pickup tabs, near the middle? You can see the tabs below.

 

 

3) Related question - I assume the two halves of the frame are kept separated like that because one side picks up the right rail, the other side the left rail, and never the twain shall meet. It looks like the motor just gets its power from the frame. In that case, can I just solder my pickup wires directly to the frame halves? Anywhere? It seems like I should be able to.

 

As you can see, I pretty much have a question about every single wire. (I didn't even ask how most people run their blue common wire, which I've also been wondering!)

 

The last question is whether I should just sell this thing and get the Kato version, which looks like it takes a drop-in decoder.

 

Thanks...

[katoftw]

It shouldn't be any different to any decoder install.  Isolate the old routes for power supply and use the decoder wiring as your new power supply.

 

I think the channels are to help keep the wiring safe.  You do not want any wires being pushed down towards the axles then you clip the shell back on.

 

Kato versus Tomix with regards to DCC install.  Personally I go Kato.  But if you begin switching and selling, you'll lose out.  Finish this install and decided whether the difficulty will warrent the change.

Edited March 7, 2015 by katoftw

[spacecadet]

I guess the main question is really the one about the light boards. How do people normally deal with that in locos like these? I just have no idea what to do with them.

[kvp]

I'm not a dcc install specialist and only have 3 japanese made, but non japanese prototype DCC-ed locos. Personally i would install a 6 or 8 pin socket onto the light board, so the loco can be run with an analog plug and this allows testing without the decoder. If the decoder fits above the light board, then on top, if not, then below with a milled out chassis. For locos with short slide in lihtboards, i would isolate the contacts at the retaining/power clips and solder wires to them. 8 wire/pin decoders have a common power out, which have to be split to the two headlights and the ground is provided by the function output. For 6 wire decoders this is solved by two diodes from the two track inputs that power the common lighting power wire.

[The Next Station Is...]

I'm doing a Tomix DCC conversion with the DZ126T as well.

 

I'm ditching the light boards altogether and soldering in some tiny 1.5mm LEDs that I've used in my Kato DCC installs. You might need to do a bit of 'light shielding' but black electrical tape will do the job.

 

I'm dropping down my motor wires through a gap behind the motor but I am cutting channels in the top so the decoder wires sit flush. The motor is easy to isolate from the frame in my DE10, so I'm not using the frame.

 

That brings me onto the track pickups. My model has copper strips pushed into the frame; it'll be much easier to solder the pickup wires to these so I'm going to cut channels for the wires to them.

 

Hope this helps!

[Martijn Meerts]

The motor needs to be isolated from the 2 halves. I usually shorten the copper tabs on the motor, and solder some wires on the shortened tabs, making sure they don't touch the frame halves once reassembling the locomotive again. You could solder the power pickup wires (red and black) to the frame, but these frames are made of a type of metal that's really hard to solder anything on.

 

The light boards can be isolated with a bit of simple electrical tape, that shouldn't be an issue.

 

Actually, a lot of Tomix locomotives are built up like this, so if you manage to do one, you can do all the others as well ;)

[kvp]

One tip for the track pickups. The lightboards have excellent contact pads. If you cut the traces between the pads and the rest of the light circuit and solder the decoder track pickup wires to one of the light boards, then you just isolated the light boards and have a good and easy to disconnect pickup for the decoder. Makes it easy to remove the decoder, since you just have to bridge the cuts to restore the original circuits. For old style bulb lights, you can make small contact pads that touch the frames like bulbs and then you can get the track power this way.

[spacecadet]

One tip for the track pickups. The lightboards have excellent contact pads. If you cut the traces between the pads and the rest of the light circuit and solder the decoder track pickup wires to one of the light boards, then you just isolated the light boards and have a good and easy to disconnect pickup for the decoder.

Thanks for that tip! I'm going to look at the light boards again today; one modification I might make (just going from memory of what the top of them looks like) is cutting the contact pads themselves about in half and then soldering my pickup wires to the back (where the pad contacts the frame) and the light wires to the front (which would still be connected to the light). It might be tricky cutting a big pad like that but I'll just have to try it. I do have a multimeter to test that it's really fully cut once I do it.

 

That plan minimizes frame modification too. My wires should all fit through the gap between the halves of the frame, although I might still need a small channel along the top for the light wires. This is sounding easier and easier - as long as it works!

[johnnocino]

Being a newbie I lost the plot somwhere when I started getting set up for DCC then went and ordered a Tomix DF200-100 only to discover it is not DCC ready...so... older but wiser I will stick to Kato. Rather than leave the loco in in its "glass case" to be admired, I prefer to resolve the problem. Based on the info in this topic I am presuming it will be possible for me to wire in a decoder. Having read the various posts I am still unsure which decoder would be best suited. I am not really worried about lights/sound at this stage, I just want to get the loco set up and running. Suggestions on suitable decoder would be really helpful. Apologies if I should have started a new topic elsewhere.

Edited May 18, 2015 by johnnocino

[Ochanomizu]

I'm not a dcc install specialist and only have 3 japanese made, but non japanese prototype DCC-ed locos. Personally i would install a 6 or 8 pin socket onto the light board, so the loco can be run with an analog plug and this allows testing without the decoder. If the decoder fits above the light board, then on top, if not, then below with a milled out chassis. For locos with short slide in lihtboards, i would isolate the contacts at the retaining/power clips and solder wires to them. 8 wire/pin decoders have a common power out, which have to be split to the two headlights and the ground is provided by the function output. For 6 wire decoders this is solved by two diodes from the two track inputs that power the common lighting power wire.

 

You are effectively making it DCC Friendly.  Good, commonsense advice!

[katoftw]

Being a newbie I lost the plot somwhere when I started getting set up for DCC then went and ordered a Tomix DF200-100 only to discover it is not DCC ready...so... older but wiser I will stick to Kato. Rather than leave the loco in in its "glass case" to be admired, I prefer to resolve the problem. Based on the info in this topic I am presuming it will be possible for me to wire in a decoder. Having read the various posts I am still unsure which decoder would be best suited. I am not really worried about lights/sound at this stage, I just want to get the loco set up and running. Suggestions on suitable decoder would be really helpful. Apologies if I should have started a new topic elsewhere.

Put it on ebay and buy a Kato version.

Edited May 19, 2015 by katoftw