whart57

This is one thread I wish I had known about ages ago, but not being a regular on RMWeb I missed it My interest is in Thai railways, which I am building to 3mm scale on 9mm gauge track. My layout is based on Bangkok's Thonburi station, though I have no intention of making an exact copy of that. Some of you might have seen the articles I wrote for Continental Modeller a few years ago, which I hope some people will find useful at some point. At the moment I have a GE 4000 class and an Alstholm completed, with another Alstholm near completion. I also have a couple of third class coaches built and have the etches for another five. I have resin casts for four wheeled freight vans and I have a trio of BCFs as well. I am working on container flats and fuel tankers as my layout also takes in the Khlong Thoei branch to Mae Nam (near the Rama IV road and the Thai boxing stadium in Lumphini), as Thonburi has no freight these days. I'm thinking of calling the layout Maenamburi! I try to avoid scratch building and most of my stuff is etched brass done to my artwork. The reason I came across this thread is that I have asked someone to do a 3D print job of the Thai 158 (he already does the BR version so it's a mod rather than a complete new item, but the beauty of 3D printing is that mods are relatively simple to do compared to other technologies). What he needs is some pics of the roof in order to get the aircon and other grilles right, so if anyone has any shots of a Thai Sprinter taken from above, can they post them here please? Thanks Wim

It's also worth checking the Web for 1:100 figures, cars etc. 1:100 is a scale used by architects to model projects for clients. Bought through architect's suppliers they are expensive but they are often available cheap in bulk over the Internet. The Chinese suppliers do use 1:100 and HO interchangeably so it can be a gamble. I have bought about 500 figures and 100 cars this way.

I stand corrected, thank you

As has been pointed out elsewhere in the thread of replies, the 3mm Society is a scale society and not a gauge society. As a result the Society's published wheel and track standards can appear confusing when set against those from P4, S guage or the 2mm Association. The easiest way to pick a way through the undergrowth is to think of the Society's standards being three sets of wheel standards. The coarsest is the legacy Triang standard, set by Triang over fifty years ago when every railway model manufacturer thought trains were steamrollers on rails. The problem for the 3mm Society is that Triang did such a damn good job at the time making indestructible mechanisms and producing locos, coaches and wagons that were superior to their OO counterparts that a lot of Triang TT is still in use today. However, similarly coarse wheelsets are delivered by Continental TT manufacturers at least until very recently. The next standard is the Society "Intermediate" standard. Not a very good name as it doesn't convey the fact that this is the more forgiving of the two wheel profiles used by the 3mm Society for the wheels they sell to members to use on the rolling stock they build. In the past wheels have been made to this standard by Chris Hardy, Romford, Kean-Maygib and Alan Gibson. The Sharman Millimetre range also fitted this profile. About four years ago the 3mm Society launched their own SQ (self quartering) range. These have a square axle hole for ease of quartering, and - more importantly - ensuring wheels stay properly quartered. Dimensionally these wheels are about 0.5 mm too wide for exact scale and the flanges are approximately twice as wide and deep as the exact scale equivalent. In proportion these wheels are only slightly coarser than 2mm FS are of a similar fine-ness as 7mm finescale and are a little finer than RP25. Or RP25 as was, the NMRA seem finally to have twigged that RP25 doesn't match their own wheel standards The Society also drew up a Finescale wheel standard and through the 1990s produced loco and rolling stock wheels to that standard. The full range is still available to Society members. These wheels are correct scale width, albeit that the upper tolerance is about 10% over scale width, but flange width and depth are about 50% overscale. The fact that 3mm Society finescale wheels are still a little overscale has led some people to propose an S3 standard, one where wheels and track are built to exact scale. The reaction of most 3mm Society members has been along the lines of "best of luck with that" and certainly the Society, nor anyone else, has not delivered any product to that standard. All three wheel profiles have been used on different gauges The legacy Triang profile, and its modern commercial TT relations, is really only for 12mm gauge though back in the 1980s a layout appeared in the model press where Triang wheels had been pushed out to allow the rails to be set 14.2mm apart. That approach is not recommended by the Society. The Intermediate profile is intended for 12mm gauge though the Society will sell axles for the SQ wheels that allow them to be used on 13.5mm or 14.2mm gauge track. Track standards have to be tweaked however, flangeways widened, so that these wheels can pass through crossings. I personally have built a small test track with three points to 13.5mm gauge and using Intermediate profile wheels and it seems workable. The finescale profile has been used with 12mm gauge but most of those who use the FS wheels also use an exact scale track gauge - 14.2 mm for standard gauge, 15.75mm for Irish broad gauge and 21mm for Brunel's broad gauge. George Mitcheson was building an ambitious 13.5mm gauge layout using the finescale wheel profile on his stock but I believe a change in circumstances has meant this project has been shelved. As to what works, the best thing is probably to view some of these layouts at shows. At the Crawley MRS show this weekend there were examples of 12mm gauge using Intermediate standard wheels (Paul Hopkins' Redford Junction and Tony Briddon's Bilton Goods), 14.2 mm gauge using finescale wheels (Peter Bossom's Whatlington and the Croydon MRS' Hemyock) and 15.75 mm gauge using FS wheels (Ballyconnell Road). All fine layouts demonstrating what is possible in 3mm scale. There will be similar pods of 3mm scale layouts at Wells and Warley later this year, showing the different ways of modelling in the scale and in October, in conjunction with Worsley Works there will be a 3mm scale only show in Kidderminster. Hope this helps 3mm Society Chairman

Why did 3mm scale end up with three gauges? The same reason 4mm scale did - the original commercial scale-gauge combination was wildly out. That and the fact that unlike the US, here in Britain we don't have a powerful national model railway association that everyone is prepared to follow behind. Instead what happens is that individuals use what is available and a series of de facto standards evolve which are later adopted in a more formal manner. Sometimes what happens is that a standard is reinforced by products being made to it. That's what happened with P4 where the key things like wheels, rail, gauges were all produced together. To some extent the same thing happened in the 3mm Society where the 14.2mm gauge standard was backed up with a major wheel production programme overseen by the then chairman of the Society, Peter White. Add in some other bits and pieces like the gauges produced by Finney and Smith and the rail commissioned by the Society and the 3mm FS modeller had a consistent set of wheels, to a consistent profile, decent rail and good quality gauges to put the whole lot together with. The flexible trackbase that appeared two years ago was the icing on this particular cake. Meanwhile elsewhere the only real standard was the Triang one. Although finer scale wheels were available supply from the various manufacturers was often interrupted and there was no consistency in wheel profile as manufacturers tended to use a profile tool they already had. That changed 18 months ago when the 3mm Society embarked on a heavy investment programme to produce a new generation of wheels suitable for 12mm gauge modellers. This time the decision was taken to standardise the profile to the NMRA RP25-79 recommendation (which is the profile the NMRA recommend for TT gauge) and thanks to some skilled work in design and toolmaking these wheels were provided with square axle holes for both ease of quartering and secure fitting. An expanding range of these wheels has appeared and are likely to keep appearing over the next few years. I'm guessing, but I suspect that the appearance of some really nice wheels has fostered a revival of interest in 13.5 mm gauge. It was a trivial matter for the Society to produce a small number of longer axles and with a benefactor funding the production of a flexible track base that gauge now also has a range of bits that are consistent and have a high guarantee of future availability. Whether that will mean 13.5 has long term popularity only time will tell.