Thursday, 19 May 2011

DCC decoder fitting for Association Class 08/11

A very long time ago (about 3 years!) I posted here about an ex-LMS class 11 diesel shunter I had been building from the 2mm Scale Association's then new kit. Guess what - I'm still building it, but things have progressed a little... although not by much in the last 2.5 years as other projects have captured my limited attention.

So why the update now? Somebody wanted to know about how I installed the DCC decoder that I was getting round to in the last post, so here are a few piccies to illustrate what I did.

The decoder is a CT-Electronik DCX-75. This is a single sided board, and very thin. Its width is the same as the outside width of the loco frames, so it can sit comfortably on top of the frames and between the wheels - as can be seen in the photo below. Attachment is by double-sided sticky tape. There is plenty of room below the motor (or "boiler" as I keep wanting to call it!)Red and black wires attach to the top of the PCB frame immediately in front of the decoder. Orange and Grey to the motor. The yeallow and white wires provide this decoders only two function outputs (return must be to the track).
I wanted the function outputs to power lights (cab light and marker light) on the loco, but still retain the facility to separate the body from the chassis. This is achieved by the two phosphor bronze springs which appear to be poking up from the front spacer. What you can actually see is a very thin PCB pad glued on top of the front spacer, and insulated from it and the side frames by paper (probably a shred of post-it judging by the colour!). A close up is below:The wires reach this pad from below, accessing it through small holes in the front spacer:The underside of the PCB footplate has been gapped to form two large pads that the springs push against to transfer power to the LEDs:

The return path is via a suitable resistor, to the cosmetic outside frames, which though attached to the underside of the footplate, are live to the chassis sides when everything is assembled. The positioning of the decoder relies on the fact that I have not added the optional idler gear between the front two axles. There may also be room on top of the motor for a very thin decoder such as this. Another option would be to put a shorter, fatter decoder upright in the front of the bonnet - a DCX74zD should fit there, but at the expense of being able to easily separate the body and chassis.

Tuesday, 15 March 2011

David Eveleighs GWR Toad

David Eveleighs GWR Toad as built by the author

From the etch supplied it would be possible to produce the first three GWR Covered Veranda Toads by modifying the sole bars, wooded, bulb the steel underframe is supplied). By changing from 4 to 8 shoes AA16 can be produced, if you feel brave you can shorten the roof back to the doors, remove upright supports that supported the roof and you will have the Toad built 1874 as detailed in the latest edition of "Great Western Way". That is not a bad selection from one etch.

Thursday, 17 February 2011

"WILLIT END" Cattle Dock

Two views of my second etch project a GWR Cattle Pen based upon "Gilfach" constructed from broad-gauge rail which was represented with etch and guitar string.

The first view has my W2 cattle wagon in front of the dock and just to the right you can see the end of my build of David Eveleigh's GWR Toad Lot 355 of 1886 with 4 shoe brakes.

The second view is the dock and gate

Monday, 15 November 2010

The train about to run itself is on platform 3

At Warley show this year, on 20th and 21st November, there will be a demonstration of DCC topics in 2mm scale.

Included in those will be my automatic sidings plank, which can run trains, uncouple and shunt wagons, etc.. It can also be run manually for those who want to twiddle with knobs and work a proper lever frame.