A MERG DCC System

Over the last couple of posts, I’ve been building up to completion of a DCC system assembled from MERG kits.

Last week, I had the pleasure of taking it to the South London Group’s clubroom, to trial it with our new layout. It worked!

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What we can see here is (starting at the loco on rollers), a class 20 on the ‘layout’ output of the system. To the right is the programming track, and alongside that we can see the command station. This provides the DCC signal for the layout, and a direct connection to the programming track. The command station has no directly attached controls, and cabs (one is at the bottom) are connected over CBUS. Since CBUS is a publicly documented standard, I intend to develop custom handsets over time. I’m intrigued if exhibition layouts will be easier to use if the controls are designed with the operation of the particular layout in mind.

To the right of the picture, the top board is a 5A DCC booster, which provides the actual layout power and DCC signal broadcast. Below it is a USB to CBUS connection. Not directly needed for the system to function, it will facilitate future firmware upgrades to the command station and handset, and permit me to prototype the custom handsets on a PC before committing them to electronics.

Surface Mount Practice

MERG provide a couple of kits intended to be used as practice for surface mount soldering. This is my second go at this, and the first working attempt:



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My first attempt failed because I wasn’t familiar with how pin 1 on the IC was identified. I now know it is the chamfer along one side. My first attempt had the IC the other way round, and rapidly burned out without flashing the LEDs, as this circuit is designed to do. For a £3.60 kit, it seemed like a good value way to learn the lesson. The instructions did explain all this, but somehow it still didn’t sink in without the practical lesson!

A MERG DCC Controller

I want to explore the options that present themselves when lots of my layout wiring is digital. Step one is to drive trains via a PC.

MERG have a set of kits for a system designed around the CAN bus. This is the ‘DCC command station’ and a USB to CAN interface module. The loco lurking in the background moved under the power of this system earlier tonight.



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Now I want to build a handset so that the computer is optional. The kit MERG have will mean I need to get the knack of surface mount soldering by hand.

This also means JMRI is installed on my PC again. It’s nice to see how much that has updated recently!

Published in MRJ: Exactoscale Wheels for Tornado

Yesterday, I was pleased to see an article I wrote a few months ago make it into print:

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Earlier this year, Paul Willis approached me to write this up, having seen the similar article I had written for the Scalefour societies newsletter. I was honoured to think something I was up to was worthy of MRJ, which is a magazine that sets an incredibly high standard for the models it features.

I don’t think Tornado will be ready for Scaleforum (this year), as I hoped when I wrote the piece, but progress is continuing!

Thank you Paul, and all involved in MRJ, for publishing my work! I’m very pleased with the result.

Scalefour North 2013 Retrospective

I’ve just published a retrospective of the Scalefour North show this year, as part of the ongoing series published by the Scalefour Society.

I’ve gained a real appreciation of the work needed to publish photos on the web. The web is a text heavy medium, and a given image can have a title, alt text, copyright description, and then perhaps one or more captions. All of this needs hosting in some HTML, if you want to display this text with the image.

Finding some way to write all that text with ease is something I need to work on. The current retrospective entirely omits alt text, for example, so that browsers who can’t see the images can’t see a description of what would be displayed.

After that, there is then the problem of image size. Something which shows off the detail in these models is important, and I think it should be big enough that it visually dominates the html page hosting it. However, that leads to typical pages spilling out over the edges of the browser window, and scrolling when you want to take in the picture as a whole is not ideal.

If anyone has examples of this done in ways they like, posting links in the comments would be appreciated!

John

March 23, 2013

It’s snowing, so something indoors this weekend. Seeing other’s models appeals more than building my own, so I’m off to Ally Pally for The Model Railway show (is it still called that?)

A Year Ago

Having started from a fresh kit, the first weekend of time I spent with Tornado was making some basic assembly decisions, and then getting started on the mainframe.

Given the kit’s design, the consensus of advice was to assemble it without the aid of a chassis jig. It is very carefully designed to fold up square and true. This seemed reasonable, but I certainly felt a bit wary getting started.

So far, the chassis seems to roll well as an 0-6-0, so the advice was sound!

After a weekend’s work I had:

Tornado mainframes, coupling rods and driving wheels

So far, assembled exactly as the excellent instructions suggested.