I have been a 3mm modeller for some 30 years, originally using 12mm gauge. Some may remember my layout 'Wray' which was widely exhibited in the '90s. I am at present building a small layout using 13.5mm gauge. Difficult? Not at all; I have sets of gauges which were marketed by Finney and Smith and make track building a doddle (I'm using soldered track with PCB sleepers, at least for pointwork, and 3mm Society 13.5mm track bases for plain track). Why 13.5? 3mm modellers are by nature bloddy-minded - why else would you chosse a scale with virtually no trade support? 12mm always looked very narrow; and I have stocks of the old Sharman millimetre range driving wheels which are too wide in the tread to work well in 14.2. 13.5 seems to be a good compromise for me. But then I don't consider myself a finescale modeller - I just want the overall effect to be convincing. When using 3mm Society finescale wheels one can request axles shouldered either for 14.2 or 13.5, so that's all right. The new intermediate wheels with square-ended axles are likewise available with 13.5 axles. Rolling stock wheels can simply be regauged using a suitable back-to-back gauge. And I'm modelling the Furness Railway in 1908. Small locos so the extra space between the fames compared to 12mm is useful for fitting motors in. I think 13.5 is OK. I've just this week built my first ever single slip, and that seems to work fine. If you're thinking of 13.5, give it a go.
Ian
