Wiring thoughts

Was directed to Brian Lambert's site via the N Gauge Yahoo! group. Brian's site is excellent, loads of detail and practical experience, clearly explained.

I need to think about wiring now, before laying track, as holes for dropper wires will have to drilled for wiring as track laying progresses, and I don't want to make it up as I go along.

From Brian's site, and other readings, here's my basic track wiring plan:

Use a bus architecture for the main rail power feeds. 'Bus' is a fancy word for cable, and it will run around the underside of the baseboard following (roughly) the track main line. Two wires are required (live and neutral) and I'll use the red and black wires from household electric mains cable (2.5mm twin core and earth).

I'll then drop wires from the rails at appropriate places. Probably I'll use the wire-soldered-to-rail-joiners method - easy to solder first and join later, rather than faff around with soldering to the outside (ugly) or underside (easy to melt sleepers) of the rail.

Dropper wires will then be connected (terminal blocks or soldered) to wires that will then run to the bus.

Point wiring can be considered separately, except when track polarity needs to be switched by a point motor. The only place I think this applies is the long crossing. Polarity of point frogs is switched automatically from the switch blade making contact with the stock rail. (I'm using Peco code 55 electrofrog points throughout.)

Questions:

Should I draw up a full wiring plan? Probably.

Do I want to wire the switch blades of points, or depend on contact with the stock rails? My inclination is to rely on the stock rails, as wiring up the point blades involves intricate soldering (with the risk of messing everything up).

At least I don't have to worry about isolated sections, as my DCC decision removes this requirement.

Installing a decoder in a Dapol M7

This is my first foray into DCC decoder fitting, and I’m pretty much a beginner in soldering and general delving into the innards of a loco. So I started with much trepidation.

Why the M7? Well, in my mind it's not an M7 at all, but an ex-Caledonian 0-4-4 Class 439 that worked as bankers at Beattock. Since there's no RTR version or kit available the M7 is the closest I can get without scratch-building (one day perhaps...).

The basic conversion approach is that described in Railway Modeller June 2006 by Roger Miller. Some of the pictures in the article are unclear (they were to me anyway) so I've included my own here.

The basic steps are:

 

Remove the body from the chassis, and clamp the chassis in a vice or similar (I used one of those crocodile clip stand things).

  

I used a Digitrax DZ125, bought for £17 from Digitrains.

  

I used a pointed soldering iron tip, for accuracy.

  

First step: unsolder the suppressor coils. There are two, and they come away quite easily by applying the soldering iron.

  

A removed suppressor coil.

  

Removing both coils it looks like this.

  

Then unsolder the capacitors (those little orange blobs). Here's the prepared chassis resting on the handle of my wire cutters.

  

You need to remove the yellow and white wires from the chip. No going back now...

  

Solder the wires, one at a time, ensuring the bond is strong (ie it stands a gentle tug - don't yank it!).

  

The chassis with all four wires soldered on.

 

On the test track, set the chip ID to the loco number (or whatever convention you're using). Amazingly, my effort worked first time. I noticed that the loco now crawls around the test track at speeds much slower than I could get using DC.

Bachman Dynamis arrives!

I’m like a kid with a new toy. I am a kid with a new toy. My Dynamis arrived today, bought for a snip of £80 from holtmodelrailways.co.uk. I’d previously read reviews of this set in Model Rail and BRM, and they both rated it highly.

First impressions are that it’s duffer-proof. Easy-to-read manual, simple track connections and a basic but functional handheld controller (or throttle as we DCCers say…).

Now to install a chip (sorry, decoder) and test it for real…

Why DCC?

I've given this issue some thought, but ultimately it comes down tho two things:

1 - I'm building this layout in 2009 and to me it makes sense to use the latest technology. There's no cost barrier for me in terms of pre-existing stock, and I haven't accumulated that much, and I'll convert locos as I go. Most new products come DCC-ready or have well-documented conversion approaches.

2 - Operationally, Beattock was all about bankers. I need a way of controlling two locos at once and while this could be done in DC it's not simple or reliable. In DCC it should just be a case of creating a 'consist' ( which can be preset or done as needed) and then the two locos will operate together. I guess there may be some issues of speed differences, but I'll cross those as and when. DCC also makes double heading easy, and there was a lot of that going on a Beattock too.