Why 3mm/ft a short FAQ about 3mm/ft.

[Katier]

Why 3mm ft?

 

Sitting between N-gauge/2mm/ft and the various 4mm/ft gauges 3mm or TT can give the best of both worlds in many ways. Space wise it is ideal for that space where you can't quite fit a OO gauge model in while retaining a scale that is still reasonably substantial for those hamfisted people or those with fading eyesight. As such it gives a modeller the chance to keep the layout reasonably compact while still being fairly significant in size.

 

As an example my railway, which is still under construction, easily fits a 6 coach station, significant length of station throat and substantial goods facilities in an 8ft running length (plus 3-4ft for fiddle yard), with a maximum width of 2ft for the first 4ft, then 1ft for the second. In 4mm such a layout would probably be limited to a BLT of some sort, while a 2mm/ft probably wouldn't add a lot in terms of functionality.

 

What is available?

 

Triang TT RTR is still around on ebay and such places but is fairly old these days. The range of locomotives is fairly limited but on the positive side you want work to the intermediate standards (more on them later) and still accomodate TT rolling stock.

 

Continental TT RTR is still made and readily available.

 

RTR track is available from Tilling ( continental ), Peco ( HOm range ) or from the 3mm society ( flexi track only ). 3smr also have a point building service at prices comparable to Peco's HOm points so is a viable alternative.

 

Kit wise there is a HUGE range of kits available, easily comparable to any larger scale and probably more than 2mm/ft . Many of the etched brass kits are 'shot down' kits and generally go together no harder than their 7mm cousins, with the exception of the natural increase in difficulty due to the smaller scale. The entire Connoisseur 7mm range is available, for instance, and assembles very nicely ( my first kit was the TINY J79 which went together just fine ). There is also a wide range of white metal kits, usually ex-GEM or similar, which go together very quickly and make a good introduction.

 

Full range of track and sleepers is available for hand built track.

 

General accessories are well catered for (track side stuff, station facilities etc.) and of course Scale-scenes can be reduced from 4mm/ft to 3mm/ft easily enough.

 

What standards are there?

 

A full description can be found on the 3mm Society website ( see below ) but in summary there are three 'standard gauge' gauges which are roughly analogous to OO/P4 and EM. 12mm (the old TT gauge), 13.5 (which helps with tight clearances for outside valve gear and the like) and 14.2 which is the correct scale gauge. The Society publishes coarse, intermediate and fine standards for 12mm gauge, and fine standards for 13.5mm and 14.2mm gauges.

 

What suppliers are there?

The main suppliers are :-

 

http://www.3mmsociety.org.uk/ They have a huge list of kits, parts, track, accessories, wheels and also a used/second hand store. Also a must join society with excellent advice from some dedicated modellers.

http://www.3smr.co.uk/ Etched and WM Kits, Accessories, secondhand TT, motors/gearboxes and track including made to order/RTR pointwork.

http://www.finneyandsmith.co.uk Etched brass kits ( the aforementioned Connoisseur and others) alongside motors/gearboxes and accessories.

http://www.worsleyworks.co.uk Etched brass kits

http://www.mouse.biz Bill Bedford does a large range of Etched Brass coaching and other stock available made to order for 3mm/ft. http://www.mousa.biz...e_to_order.html

Edited January 11, 2012 by Katier

[Allegheny1600]

Hi Katier,

Thanks for your run down of 3mm scale today, I have followed 3mm as an interested observer for many years now, one of my old teachers was very into it!

It does surprise me and almost seems ironic though, that 3mm scale has 3 gauges!

How did that happen? Oo-oh! I don't want to start a gauge war, is it the same as EM-P4?

Cheers,

John E.

[Katier]

Hi John,

 

I believe (but am prepared to be corrected) that the society that the society developed 14.2mm out of a finescale 'Scale 3' development in the early 70's and is equivalent to P4.

 

13.5 I suspect simply came about because people found 14.2 just too tight for comfort but still wanted a closer to scale appearance than the 12mm.

 

There are naturally advocates of all 3 gauges but certainly isn't a gauge war and indeed the Society supports all 3 gauges .

 

12mm is the only option if you want RTR but i believe it's just about possible to regauge 12mm stock to 13.5 but not really practical to 14.2. Personally I went 12mm because I didn't want to make things clearance wise any harder for myself but 13.5mm gives a useful bonus of wider frames so you can fit gearboxes in just a little easier ( the highlevel boxes are pretty much an interference fit at 12mm).

 

As I have not modelled in either of the two wider gauges I can't really say which is the best, however, the best place for that kind of advice would of course be from the 3mm society members.

 

Kat

[Chris Higgs]

Hi John,

 

I believe (but am prepared to be corrected) that the society that the society developed 14.2mm out of a finescale 'Scale 3' development in the early 70's and is equivalent to P4.

 

13.5 I suspect simply came about because people found 14.2 just too tight for comfort but still wanted a closer to scale appearance than the 12mm.

 

My understanding is this. Although 14.2mm is almost exactly the correct scaled-down track gauge, unlike P4 where everything is just scaled down, including loco wheel widths, flange depths etc. the 3mm version does not do this, with a more pragmatic set of other standards. That, as it does in 2mm Finescale, produces a side effect that overall widths of wheelsets is overscale, and hence you get issues with things like splasher widths, clearances behind outside valve gear and so on.

 

Using 13.5mm gauge (which is the same in 3mm scale as 18mm i.e. EM is in 4mm scale) gives a good solution to these issues.

 

12mm is just the track gauge of continental TT, and like OO in 4mm scale, is what the commerical manufacturer at the time (Triang) decided on when they produced commerical stuff way back when. Use a British scale for the locos but a continental scale for the track. It lives because it's what most people still choose to use.

 

As in 4mm scale, the three track gauges are not going to go away. Unlike 4mm scale, there is no war going on about them.

 

Chris

[Guest Natalie Graham]

You missed one of the best things about 3mm scale, particularly for scratchbuilders, which is the convenient 'scale inch' of 0.25mm (and, near enough, .010") which makes working out dimensions and marking out components very much easier than other scales. My view is that 14.2mm is the easiest gauge to work in. You don't have to worry about loco driving wheels fouling the boiler and there are quite a few motors which fit comfotarbly between the frames on the wider gauge but not 12mm. Plus it looks a lot better.

[Katier]

I think it would be interesting if we could get 3 photos organised of the same outside valve gear loco in all 3 gauges. Be quite interesting to do a side-by-side comparison the the arrangement of the motors etc.

 

I can certainly see how a 10xx Mashima could disappear into a 14.2 frame as in 12mm it does nestle into the top of the frame already, the motor is pretty much exactly the outside width of the frame so the curved 'belly' nestles in the frames.

 

I should add that GeorgeM, who is probably the leading advocate of 13.5mm, I believe does run a slightly altered spec as he feels that the published 3mm specification doesn't improve the clearance situation as much as it could do (without, of course, affecting the look of the model).

[Guest Natalie Graham]

It is a good few years since I had anything to do with 3mm modelling but I don't recall clearances for outside cylinder locos ever being raised as an issue. After all, the difference between 13.5mm and 14.2mm is only a third of a millimetre on each side of the loco. 13.5mm wasn't really regarded as a mainstream option then, it was more an idea that had never caught on. Maybe opinions have changed since.

[Katier]

I THINK George runs 13.5 so the back to back is slightly narrower than specified which gives more working room outside of the wheels.

[Chris Higgs]

It is a good few years since I had anything to do with 3mm modelling but I don't recall clearances for outside cylinder locos ever being raised as an issue. After all, the difference between 13.5mm and 14.2mm is only a third of a millimetre on each side of the loco. 13.5mm wasn't really regarded as a mainstream option then, it was more an idea that had never caught on. Maybe opinions have changed since.

 

Well there almost certainly will be a clearance issue. In 2mmFS, we have to move the effective centres of the cylinders outwards to clear the coupling rods and valve gear behind. This is normally done subtly by placing the hole and slots for the slidebars off-centre in the outside cylinders. These issues tend to arise more with etches shot-down from larger scales where these specific dodges have not been designed into the kit. Cutting off the splashers and moving them marginally outwards is an absolute pain.

 

Even in P4, often the front crankpin often has to be omitted to avoid fouling the valve gear.

 

The fact that the 3mm Socieity now do moulded track for 13.5 I think shows it has caught on. Or alternatively one well-heeled devotee stumped up the money to produce it. :-)

 

Chris

[Guest Natalie Graham]

I'm not particularly wanting to argue the point, just expressing interest/surprise that 13.5mm gauge now seems to have a following as in my time modelling 3mm scale it was more kept in the standards because the guy who originally thought it up was still sticking to it and in case anyone else fancied a go. I don't think there were more than two or three people who used that gauge.

 

Again with the clearances, I was never aware of anyone raising this as a problem with 14.2mm gauge.I'm not saying there wasn't one, just that it never seemed to be a problem that was aired as a drawback to 14.2mm gauge. I think I only ever built one loco with outside cylinders which was a Highland Railway castle 4-6-0. On that the cylinders are just basic cylinders attached to the frames so I think I just took the measurement from where the crosshead shaft was on the model chassis and fitted them to line up. I had a kit for a Strath or Duke (can't remember which offhand) which a reduction from 4mm. I never got any wheels for that as the Society was having wheel problems but if anything would have shown up the problem, that would. There have been some excellent 14.2mm gauge locos built with outside cylinders and valve gear so whatever problems there might be are clearly not insurmountable. I certainly wouldn't regard it as sufficient to put me off modelling in that gauge.

[Stuart-AU]

HI..

 

I think it a bit like apples and oranges..

Model 3mm in the gauge you feel best suits your skill level..

 

 

StuartM

[Allegheny1600]

Hi everyone,

Many thanks for that over-view of the different gauges, I see why it arose now!

As an outsider, it just seemed a pity that a 'minority' scale had divisions among which gauges to use but I guess the actual gauge modelled is chosen to fit the modellers skills and experience/preference. Anyway, I'm glad theres no 'war', keep up the good work!

Happy modelling,

John E.

[Nigel Brown]

Hi All

 

The three "standard" gauges came about for much the same reasons as in 4mm/ft; the commercial gauge was followed by attempts to get closer to the correct gauge. S3 to 14.125mm gauge was proposed by John Delaney and Stewart Hine in 1972, but as it involved manufacture of your own wheels it didn't get beyond the dedicated few. Somewhere around the same time Ken Garrett proposed 13.5mm gauge, using standards which enabled the use of commercial wheels from Sharman, Kean Maygib and others, and I believe that around that time the 3mm Society published similar standards (Intermediate Standard) for 12mm gauge, again to enable better running with those wheels, and to get away from the coarse Triang standards. I believe GeorgeM uses the Ken Garrett standards in 13.5mm gauge, while most current 12mm gauge modellers use the Society's Intermediate Standard.

 

A more recent and major change (late 1980's I think) came about when the Society decided to actively support 14.125mm gauge, and published their Fine Standards to form a basis. The support included developing a wide range of Fine scale wheels, and providing Code 60 rail (with chairs from member Ian Osborne); the Society now offers 14.125mm and 13.5mm track bases, and chairs for pointwork, with more components in the pipeline. Fine standards were also published for 13.5 and 12mm gauges; I don't know if anybody uses the former, but a few certainly use the latter.

 

As Chris Higgs said earlier, the Fine standards are more pragmatic than S3; they're almost identical to P87 but with a

slightly deeper flange. That makes them around 0.3mm overwidth. For inside cylinder locomotives this doesn't seem to be a problem; I've had to scrape out the insides of splashers on a couple of old whitemetal kits (which I wouldn't use these days anyway), but that's it; the Mitchell GWR 517 etched kit I built was very tight, but that's more the nature of that locomotive.With outside cylinder locomotives it depends; I've built a Mitchell Manor with no problems, but on a Worsley Works 42XX I had to drift the cylinders out a bit (not noticeable, to me anyway), even the GWR had to resort to dodges like recessed crankpins with that one.

 

So, in summary, apart from the dedicated Triang enthusiast, in practice the majority of modellers use 12mm gauge intermediate standards, there's a fair number using 14.2mm Fine standards, a few using 12mm Fine standard, and at the moment 2 or 3 using the 13.5mm Garrett standards, although interest in that seems to be increasing.

 

I've mentioned the Society Fine standard wheels. With the disappearance of the Sharman, Kean Maygib and Romford products, the Society has now introduced a broad range of wheels to RP25 code 79 standard, which are compatible with Intermediate standard but are a lot finer in appearance than the earlier commercial products; they use square-ended axles similar to Romford, which helps with quartering.

 

Hope that supplements what Kat and others have written.

 

Cheers

Nigel

[Phil Copleston]

Hello all,

Thanks Nigel, your synopsis of the development of 3mm gauges is most helpful.

But in answer to John E's (Allegheny1600) earlier question, not only are there currently three gauges in 3mm scale (discounting broad and narrow gauge variants), more to the point, there are three (originally four) published standards!

The 3mm Society's website http://www.3mmsociet...uk/TechData.htm lists 'Triang Standard' (for 12mm gauge), 'Intermediate Standard' (for 12mm gauge) and 'Fine Standards' (for 12mm, 13.5mm and 14.2mm gauges). Apart from the gauge-dependant dimensions, wheel tyre profiles and flangeway clearances appear to be the same for all three Fine Standards. However, the Society's continuing support for these conflicting published standards (and redundant or odd gauges) has always rather baffled me.

The one 3mm scale standard not mentioned on the Society website is Scale Three, originally promoted by John Delany and Stewart Hine and published in the Society's 'Mixed Traffic' magazine issue No.29 (July 1972), pp3-11, and reprinted in 'Model Railways', January 1973, pp38-41. This was 3-mil's attempt at a 'Proto' standard.

For various reasons, this excellent attempt to break away from the old Triang toy image and lift 3mm modelling into the realms of modern finescale modelling never gained popularity. Instead, we have ended up with a mixed measure of standards in the form of the current 'Fine Standards' and the new Society wheels, which sort of work but continue to be a compromise.

I can understand why the Society continued to support the old 12mm gauge as many members at the time were committed to that standard. And although the current 14.2mm gauge standards has the right width between the rails and look reasonable and more or less work, somehow it just ain't right and still creates problems with over-width tyre dimensions and wider than necessary flangeways. As for 13.5mm, well this just seems like an evolutionary blind alley to me, which once the tiny handful of proponents eventually give up we will wonder why anyone actually bothered! (no offence, just my opinion)

I still think Scale Three is worth revisiting, and I know of some Society members who'd like to give it a go and a main supplier of 3-mil components who has offered to produce batches of rolling stock wheelsets and track gauges.

So for what it's worth, attached below is my own drafting of the S3 standards based on the original Delany and Hine figures (but converted to metric). Having satisfied my curiosity over what these standards looked like on paper for standard gauge, I then went on to prepare S3 standards for 9.0mm (3ft 0ins), 7.5mm (2ft 6ins) and 5.875mm (1ft 11½ins) gauges (not attached here). Hopefully, these may stimulate some discussion.

For those who might argue that Scale Three won't work, also attached below is a 'Comparison Table' showing the dimensional differences between S3, 2mmFS, 3mm (14.2), P87 and P4 standards in two sub-tables. This table hopefully counters the argument that Scale 3 may be too fine for practical application by demonstrating that:

In Comparison 1: Scale 3 standards are roughly comparable in measurement with established and proven standards in 2mmFS, so clearly they are achievable and physically workable; and

In Comparison 2: Existing 3mm 14.2 standards are roughly comparable in tolerance with P87 and P4 and therefore many 3mm modellers already work to such fine modelling tolerances without seemingly worrying about the actual numbers.

Anyway, I'd be interested to know what you all think of the practicality of Scale Three.

Phil

Scale 3 - 14.125mm (4ft 8½ins) gauge .doc

Scale 3 - Comparison Table - Comparison between Scale 3, 14.2.doc

Edited November 26, 2015 by Phil Copleston

[whart57]

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.

[Phil Copleston]

I hope not, whart57. I'm sure your explanation of how 3mm scale ended up with three gauges and various standards is correct. But the 3mm scale scene is still a mess!

The 3mm Society, bless it, panders to its membership's perceived 'broad church' by supporting 12, 13.5 and 14.2mm gauges, but its scatter-gun approach to new products somehow satisfies neither with a really comprehensive and co-ordinated product range. I can't think of any other scale support society which tries to back three different horses at once!

In some ways, there exists within the 3mm Society three distinct sub-genres, a 'Triang TT Collector's Society', a 'TT-3/12mm-gauge Society' and a '3mm Finescale Society', all competing for attention and limited financial resources. One wonders whether they might not be happier going their own ways?

You imply in your post that a laissez-faire approach to evolving wheel profiles and track components in 3mm model railways is somehow acceptable, yet earlier you berated the fact that our hobby lacks guidance in standards because "we don't have a powerful national model railway association that everyone is prepared to follow behind". I agree with the latter, but I don't think you can't have it both ways!

As for the future of 3mm scale, I reckon newcomers will not be beginners but are likely mainly to be experienced modellers over-spilling from other scales looking for something different, and hoping for something better than just a ¾ scale version of coarse OO. Promoting 14.2 therefore makes a lot of sense and I hope the Society will investment more in that direction to secure the scale's future.

However, the only drawback is not the width between the tracks but the muddled of track and wheel standards, which is why I think it's worth revisiting the concept of Scale Three with standards rooted in prototype practice, as per the case with P4 or S7 which are very successful. Perhaps John Delany and Stewart Hine were prescient in their early promotion of Scale Three as a 'P4 for 3mm scale' and it's time may have come at last.

Phil

Edited November 26, 2015 by Phil Copleston

[Katier]

To be honest Phil, I think you do the 3mm society a bit of a dis-service calling the scene a 'mess'. Yes you have 3 gauges to choose from and a fair argument can almost certainly be made for losing one of them. As 12mm is rooted in history that has to stay (plus is the continental gauge) and having a finescale alternative is only fair. That leaves 14.2 and 13.5 which is certainly can be argued is a gauge too many...

 

BUT

 

In actual face the ONLY items that are gauge specific are :-

 

Frame spacers

Pre-formed sleeper bases

axles for loco wheels

coach/wagon and similar wheels.

 

Everything else isn't gauge specific, some kits might only provide one gauge frame spacers (for instance the shot down 7mm usually are 14.2 by default) but many people scratch build their own chassis anyway or use society/3SMR spacers so that's really a non-issue.

 

In terms of new products, it's been fairly logical as far as I can tell.

 

12mm probably got the sleeper bases first and is the biggest customer base, then 14.2 and finally 13.5.

Wheels are the same for all gauges so it's only variation in axle width that matters.

Kits aren't gauge specific.

 

Not sure how that's 'scattergun' ?

[The Dorset Wanderer]

Lets not forget that this is the 3MM Society, not a gauge specific society. Wheels and standards are published to aid all members. No squabbling between members regarding whats wrong or right, or not that I've seen after 12 odd years of membership. Indeed it often happens that finer scale modellers help out those that are not so skilled.

[Katier]

Lets not forget that this is the 3MM Society, not a gauge specific society. Wheels and standards are published to aid all members. No squabbling between members regarding whats wrong or right, or not that I've seen after 12 odd years of membership. Indeed it often happens that finer scale modellers help out those that are not so skilled.

 

Definitely true.. heck right now one of the advocates of 13.5mm (and others) is helping two 12mm modellers with their chassis!!! Although he did seem to think our current chassis needed a bit of light tweaking with a sledgehammer!!! (actually suggesting was better to start again but when I first read his post I though he literally did mean to bend the chassis - lol ).

[Chris Higgs]

Hello all,

 

Thanks Nigel, your synopsis of the development of 3mm gauges is most helpful.

 

But in answer to John E’s (Allegheny1600) earlier question, not only are there currently three gauges in 3mm scale (discounting broad and narrow gauge variants), more to the point, there are three (originally four) published standards!

 

The 3mm Society’s website http://www.3mmsociet...uk/TechData.htm lists ‘Triang Standard’ (for 12mm gauge), ‘Intermediate Standard’ (for 12mm gauge) and ‘Fine Standards’ (for 12mm, 13.5mm and 14.2mm gauges). Apart from the gauge-dependant dimensions, wheel tyre profiles and flangeway clearances are the same for all three Fine Standards. However, the Society’s continuing support for these conflicting published standards (and redundant or odd gauges) has always rather baffled me!

 

The one 3mm scale standard not mentioned on the Society website is Scale Three, originally promoted by John Delany and Stewart Hine and published in the Society’s ‘Mixed Traffic’ magazine issue No.29 (July 1972), pp3-11, and reprinted in ‘Model Railways’, January 1973, pp38-41. This was 3-mil’s attempt at a ‘Proto’ standard.

 

For various reasons, this excellent attempt to break away from the old Triang toy image and lift 3mm modelling into the realms of modern finescale modelling never gained popularity. Instead, we have ended up with a mixed measure of standards in the form of the current Fine Standards and the new Society wheels, which sort of work but continue to be a compromise.

 

I can understand why the Society continued to support the old 12mm gauge as many members at the time were committed to that standard. And although the current 14.2mm gauge standards has the right width between the rails and looks reasonable and more or less works, somehow it just ain’t right and still creates problems with over-width tyre dimensions and wider than necessary flangeways. As for 13.5mm, well this just seems like an evolutionary blind alley to me, which once the tiny handful of proponents eventually give up we will wonder why anyone actually bothered!

 

I still think Scale Three is worth revisiting, and I know of some Society members who’d like to give it a go and a main supplier of 3-mil components who has offered to produce batches of rolling stock wheelsets and track gauges.

 

So for what it’s worth, attached below is my own drafting of the S3 standards based on the original Delany and Hine figures (but converted to metric). Having satisfied my curiosity over what these standards looked like on paper for standard gauge, I then went on to prepare S3 standards for 9.0mm (3ft 0ins), 7.5mm (2ft 6ins) and 5.875mm (1ft 11½ins) gauges (not attached here). Hopefully, these may stimulate some discussion.

 

For those who might argue that Scale Three won’t work, also attached below is a ‘Comparison Table’ showing the dimensional differences between S3, 2mmFS, 3mm (14.2), P87 and P4 standards in two sub-tables. This table hopefully counters the argument that Scale 3 may be too fine for practical application by demonstrating that:

 

Comparison 1: Scale 3 standards are roughly comparable in measurement with established and proven standards in 2mmFS, so clearly they are achievable and physically workable, and

 

Comparison 2: Existing 3mm 14.2 standards are roughly comparable in tolerance with P87 and P4 and therefore many 3mm modellers already work to such fine modelling tolerances, seemingly without worrying about the actual numbers.

 

Anyway, I'd be interested to know what you think of the practicality of Scale Three.

 

Phil

 

Scale 3 - 14.125mm (4ft 8½ins) gauge .doc

 

Scale 3 - Comparison Table - Comparison between Scale 3, 14.2.doc

 

Not wanting to get too involved as I am just a 3mm dabbler, but I do model in P4 and 2mmFS. It seems to me that the theoretical S3 outlined does differ from 2mmFS in a key dimension - that of flange depth, and there it differs by 40%. Knowing that P4 mostly needs compensation or springing with a 0.37mm flange depth, I really do wonder whether a 0.3mm deep flange would stay on the track, especially on anything but the most generous curves. And I suspect nobody has actually tried? I have a P4 layout with 5' radius curves and it needs checkrails to keep the stock on, even with compensation.

 

Don't want to say never, as they said just the same about P4, but it does seems to me that some dimensions can really only scale down so far before things like dirt on the wheels become significant.

 

Having said all that, I have never seen a connection between the flange depth and everything else in track/wheel standards. I have often wished I had some wheels that were P4 for everything except a having deeper flange.

 

Incidentally, your figure for P87 flange depth is incorrect. It should be 0.35mm (actually the spec says 0.31-0.35mm).

 

Chris

[Nigel Brown]

The 3mm Society, bless it, panders to its membership’s perceived ‘broad church’ by supporting 12, 13.5 and 14.2mm gauges, but its scatter-gun approach to new products somehow satisfies neither with a really comprehensive and co-ordinated product range. I can’t think of any other scale support society which tries to back three different horses at once!

 

Phil

 

I think you're missing quite a few things here. Firstly, the overwhelming majority of Society products are not gauge specific. Take, for example, the extensive range of quality wagon kits from Parkside and others, perhaps the thing which has received most Society support in recent years; no problem in using these in any of the gauges and standards. I've no douby the same will be true of any further new products.

 

Secondly, as has been said, the 3mm Society is a scale society, not a gauge society. This has given it a large enough membership to be able to invest in a pretty comprehensive range of products, to the benefit of all.

 

Thirdly, there's no reason why there shouldn't be a Scale 3 contingent in the society. If, as you imply, there's enough interest for one and products are there waiting to be produced, why don't you go ahead? Other members have funded their own particular interests, witness the Malcolm Mitchell locomotive kits which have been produced. There rest of us will watch with interest, and if we find it sufficiently interesting might be tempted to have a go.

 

Fourthly, the thing about the current 14.2mm fine scale standards are that they not only give good-looking track and models, but that they are emminently pragmatic. The flange depth issue pointed out by Chris Higgs is a case in point. I am comfortable with the current standards, as are others. I have doubts about how far I would have got with S3. The reason why the 2mm Scale Association has got as far as it has is that it has a pragmatic approach to standards; it is not S2. And while there is no doubt a warm glow if one models something strictly to scale, does it really matter? The smaller the scale the harder it becomes to tell the difference. Take the flangeways you mentioned; I sometimes look at mine and wonder how the wheels go through them; they certainly don't look overscale to me.

 

Lastly, the reason things are as they are in the Society is that by and large that's what members wanted, with the odd inspired nudge from a few individuals.

 

Cheers

Nigel

[MartinWales]

Hi chaps.Just to clarify a point about Ken Garrett. His 13.5mm standards were published in MRN as long ago as February 1958!

[Nigel Brown]

Hi chaps.Just to clarify a point about Ken Garrett. His 13.5mm standards were published in MRN as long ago as February 1958!

That long ago? Wow! They're almost as old as Triang TT!

[3mm Andy.]

If I remember when Ken Garrett first set up 13.5mm it was as wide he could get the wheel sets of triang to go without the need for a lathe

and other engineering machines.

[Tiptonian]

I am not a 3mm modeller, but I could easily be persuaded. At nearly every model railway exhibition, someone will be heard to say, "Ahh, TT gauge; the perfect size!"

Some years ago, I joined the 3mm society after reading the website, as the one thing we all need is good wheels that look reasonably fine. I felt misled by the website as the reality at the time was that supplies of fine wheels were in limbo and the Finney and Smith "Bespoke" wheel service in the "Starting in 3MM" section, which would have been essential to my efforts, were not to be produced due to practical difficulties, though even to this day it is still on the 3mm website. I let my membership lapse and started dabbling in 0 gauge. With newer developments on the wheel front, I am very tempted to re-join and try again if I could be certain just what was available. The clincher would be if 13.5mm square-ended axles were available for the new society wheels, and fine 13.5mm gauge wheels for stock, as that would be my chosen gauge. (It is the 3mm version of EM, I like fine wheels, have questionable skills and little time).

I am slightly saddened by the postings of Phil Copleston, who implies that there are too many standards, criticises the 3mm society for supporting them all, but seeks to introduce yet another one which would be incompatible with the new wheels produced by the society. It is logical that "true scale" standards should be laid down by agreement between those who want it; I hope that this forum encourages like-minded people to get into contact and an S3 group formed, but I feel this should not be to the detriment (resource-wise) of the current 14.2, 12.0 or 13.5 users in the 3mm society. After all, when viewed separately, few people can tell the difference between fine-standard 0 and S7, or EM and P4, so would the same apply to S3 and 14.2 or even S3 and 13.5? After all, model railways as small as this are all about creating a convincing image. Like Phil, I have seen 14.2 models that do not look right, but as I would like to support the society and would need to use its products, 13.5 would be my choice.