Tomix EH500 DCC install

[Martijn Meerts]

So, I finally got around to installing decoders into a bunch of Domino's trains. Several I had done before for myself (C57, M250), and others were just your standard motor car installs (Narita Express, Odoriko, Romance Car), however, one rather interesting project was Tomix's EH500. The obvious challenge here, is that it's a 2-part locomotive, with lights in both halves. Another issue was space for a decoder. The ones Domino sent me along with the trains were fairly big (about 3 times as big as a Lenz Silver Mini+) so there was no room for it in the half with the motor in it. In the end I ran 6 wires between the 2 halves to get it done (a smaller decoder can mostly likely be hidden inside the half with the motor, which means you'll "only" need 4 wires =))

(The images aren't the best. Took them with my new (and as of yet mostly unknown :)) point & shoot camera (Panasonic Lumix DMC-ZS7 / TZ10 for those interested). I got sick of taking progress pictures with my DSLR's, much easier with the point & shoot =))


Image 001:
Overview shot of the EH500 taken apart. Note the large plastic bit just to the top right of the motor, a small decoder, such as the Silver Mini +, would fit in this space.

Image 002:
The modified lightboard. I cut the copper traces at the marked areas, which means I can use the pads the get track power and skip having to try to find a way to connect wires to the frame halves =)

Image 003:
Wired up light board. Red and black are power pickup, yellow is rear lights, green is common (should be blue, but I used blue instead of grey, because I didn't have grey wire... Yes, it's a bit silly =)) If you look closely, you'll notice that the green wire is hooked up to the anode of the LED, but blue (green in this case) is supposed to be common anode. Needless to say, green and yellow quickly switched places after this image was taken ;)

Image 004:
The 6 wires form the half with the motor. Orange and blue (should be grey) for the motor, white and green (should be blue) for the LED, and red and black for power from the tracks.

Image 005:
This is the half without motor. It still have the cavity where the motor would be if this half was powered, and it makes a rather nice spot for a decoder. I used a bit of blue-tack like stuff to keep the decoder in place.

Image 006:
Decoder with all wires soldered on. Considering there were 2 light boards, the common wires (red, black and green) each had 2 connections to the decoder.

Image 007:
The wiring ready for a test run before tidying them up to make room for the shells.

[Bernard]

Marti - Nice install... and a bit complex. For me personally I find Tomix conversions to DCC rarely easy.

[Martijn Meerts]

It really depends on the train, obviously the EH500 is going to be complex because of the 2 halves. Kato does have the advantage of being popular in the US, and people making drop-in replacement boards, as well as their own DCC pockets (although personally I don't see this as an advantage ;))


Actually, looking the the EH500 again, you could have enough with only 2 wires between the halves. The 2 center axles are permanently connected, and they do actually have copper wires running between them, so the 2 halves are electrically connected. That means the red and black would only need to be in the half with the decoder. If you manage to hide the decoder in the motorized half, you only have to get a blue and yellow for the lights from 1 half to the other. I might try it once I get my new batch of Silver mini's, I ran out not long ago =)

[inobu]

I must say that is a good one!

Inobu

[CaptOblivious]

Do the wires not interfere with the shell at all? On my Tomix models, there is very little room between the metal frame and the shell…

[Martijn Meerts]

The shell of the part with the decoder in it did have some problems initially, but some re-arranging of the wires fixed it. I used pretty thin wire, not the (often thick and stiff) stuff that came with the decoders. It doesn't work with all trains though, there are some that don't even have enough space for anything but the thinnest wires (like the 0.1mm or 0.2mm lacquered copper wire)