There has been some talk of a modular layout for use at the AGM or exhibitions, possibly using the Connect 3 system. Perhaps this is what people have in mind:
http://spannwerk.buntbahn.de/fotos/showphoto.php/photo/1380
Hi yes, I raised this subject under "Other Topics" as (European Gauge 3) back in September 09. Only one person took it up i.e. 454.
If you look at the many photographs on the "Spur II website" the German folk have gone for modular construction with very impressive results. The emphasis seems to be on electric/battery operation as none of the very impressive locos seem to be live steam.
Makes your eyes water looking at what they have achieved !!!
We could achieve similar results with a bit of organisation and a will to make it happen. In essence it has to be said that it is no different to what the Gauge 1 folks achieved many years ago with their portable exhibition layouts combining steam, electric and battery. The first one I saw was in the village hall in Cranleigh, Surrey over 40 years ago.
regs PK
Looking at some of those radii I would estimate them to be in the order of 1.5 to 1.75 metres....
regards
ralph
It's certainly what I had in mind when I originally proposed the Connect '3' modular track, although this by far exceeds what I hoped to see anytime in the near future. My very modest plan was to try and "connect" some of the G3 exhibition layouts together (initially just end-to-end). I also in tended to use my C3 track as a 'demountable' test/garden railway. This means any track can be taken with me when we eventually downsize. It also eases some maintenance issues in my view.
As part of this concept, last year I looked at what the 'N' gauge guys were doing in the US, although their system is clearly a modular 'Layout' system, whereas in G3 it would be a modular 'Track' system. I used the Ntrak (well actually the 'oNetrak' version) to write a G3 version of their standard. This has been reviewed by 'Cabbage' and some revisions are in process (it's going all Metric for instance). It is now based on a 1 metre standard planning grid, plus the original C3 dimensions (assumes 7' twin track gap for instance). I should add that modular "get-togethers" are the fastest growing form of railway modelling in the US. I think you can see why from the photo.
So to summarise, the C3 (track connector) is now stable - and in terms of implementation, can simply be two 10mm holes correctly placed below the track end on the baseboard. I had some (single track) examples at the AGM, just using it to show Members models. (I'll post a photo). Once you can "interconnect" baseboards, then provided you build to a standard "grid" then the kind of seen gathering at Spur II becomes very achievable.
I've had quite full issues of the Newsletter recently but will devote some pages of the June issue to give an update on C3 & G3 Modular Track. If anyone wants more info about the current definitions etc - then please let me know. Several Members at the AGM expressed a keen interest to explore this potentially extremely useful aspect of G3 modelling.
I would be willing to build several sections I was proposing a couple of removal sections to attach to the garden layout to maximise versatility on the garden space!!!!
Good to hear Keith. I'll be in touch.
I've also been looking further at the Spur II website and they have a number of "standards" I've not noticed before. I've downloaded the ones which seem most applicable - and I'm going to have a look at them (assuming I can manage to translate them that is)
They are also covering at least three different gauges - Standard, plus several NG gauges with their commonality being the 1:22.5 shared scale. There are several photos from the Show featured that show standard gauge and NG track on the same module.
Can anyone in the Forum read (that is - can translate) German? :-)
Regards,
IanT
Quick Update.
Decided to try 'Google Translate' on the "Spur II" standard docs - just on the off chance...Not used it below.
Wow - It Works! I uploaded the Adobe PDF files and almost immediately I got a full translation 'screen' back. It didn't do the drawings - but I can pretty much figure that out. I can already see similarities between the German standards and the existing (NTrak based) work. Maybe they started there too?
Need to spend some quiet time (not this evening I'm afraid) to have a good look at this stuff and see where it helps (or hinders) our progression. No point in re-inventing wheels but there may be other issues in some areas (design copyrights/IP issues etc) to consider.
Regards,
IanT
I have been in contact with a Spur 2 member called Torsten Schoening. He knows of the G3 society. The Spur 2 meeting this year (as with past years) is at Schenklengsfeld north east of Frankfurt from 13-16 May. Torsten says members would very welcome, but he adds that the event is in a sport-building and livesteam is not permitted. If anyone wants to contact him let me know.
Ian T,
I discovered google translate when I was argueing with a Hungarian trucker who thought he could take his overnight tacho break in my roadworks at 4am on the M6. You dont know what lengths we go to to avoid overrunning roadworks... thanks to the person who invented moblie nroadband tooo..
On a more serious note please get in touch.. I was planning to build some kind of industrial shuntin yard for my r/c peckett that is coming on nicely... Give me something to do scenically in detail too... best get an estate car next time...!...would be willing to build some longitudinal sections as well...standard length?
Keep in touch Keith
I will be going to Reading this year any one taking a layout need a lift out the car and someone to go and get the brews in?
A quick update.
Looking at the Spur II standards, has required me to update my rather rusty knowledge of the European (MOROP) NEM standards. These are published in French & German but I was lucky enough to discover this site by an Amercian 'N' gauge modeller - who models Italian/Swiss Railways.
He's done a pretty good job of translating the key NEM standards into english and they can be downloaded in PDF formal from here;
http://blainestrains.org/slfframe.html
It might be worth mentioning that I am also aware of the NMRA standards and that they are not so different from NEM. Neither of course reflect British practice (smaller loading gauge etc) but my view is that on balance, the nearest practice to G3 is Spur II (there is no real equivelent in the US) and that we should be adopting a metric based standard.
I am sure that this will be also be slightly contentious with some, but 'Cabbage' suggested this move from the Imperial 'grid' units I had originally used (although the C3 connector was "in" metric). My view is that the UK is now 'metricised' and we should use this system going forward.
Regards
IanT
Regarding Metric units, I would comment that the Society is still selling rail in Yard lengths....will this not make it rather awkward to construct Metre length track units......it would involve short bits being patched onto the standard Yard?
There are issues in this area John but I think they are manageable.
Cabbage suggested working to a 900mm grid (lengthwise) but this also involves "losing" 14.4mm of rail (twice). My current units are all 3 foot in length - but I will probably run them in pairs and add a 'custom' 171mm "bridging" section. My feeling is that multiples of 1m lengths makes more long term sense, although 600mm is used by the NG sections of Spur II (Domino Modules).
The use of the 'grid' is only an issue when you want to build circuits - it's not really a problem if you are constructing end-to-end. I also think most people will be building what are called "custom" sections in the proposed modular standard (for example our current exhibition layouts would all be 'custom') where the lengths involved are long.
The question of Society rail length can also be addressed over time.
Regards,
IanT
When deciding modular length for straight joining sections shouldn't we also consider the length of the rail being modelled so that the rail end coincides with the end of the board thus preventing unrealistic breaks in the track?
For those modelling pre-group, branch and "light" railways, common with the exhibition layouts, the rail length used would normally be 30ft or 45ft. So assuming 2x45ft or 3x30ft we get a scale 90ft, which equates at 1215mm or approx 4ft (47.8346") making it an ideally sized protable section. Also note that 3x45ft equates to approx 71.75" thus leaving very little waste for the 2yd. rail length available from Cliff Barker.
Those modelling post grouping and/or mainlines the rail length increased to 60ft, so 2x60 would equate to 1620mm or approx 5ft 4" (63.7795"), still just about portable and probably ideal for bridging sections on a garden railway.
Regards,
Derek.
Hi Derek,
As in so many things, there is usually going to have to be a compromise somewhere. For instance you mentioned an "ideally portable size" in relation to a unit length of 1215mm (47.8"). Since "portable" (to me) mainly means being able to get it into my car boot, I went just went out and measured it.
I was able to transport six of my existing 3' units (in my boot) to the AGM. As it turns out, my boot is just over 3' square, and in fact I would not be able to fit a 1m length into it, either sideways or lengthways. So the only way I can currently carry 1,215mm length units would be across the back seat (or get a new car).
OK, maybe I should have a hatchback or an estate - but the fact is I don't have one.
But if you used (say) a 1215mm length, would you really be cutting Cliff's nice new rail into 2 or 3 'scale' lengths? And what would the 'modern' enthusiast do? Have a scale length of 60', followed by a scale 30' bit?
I'm sorry, I'm not trying to be dismissive here, but I'm afraid that whatever we do, it will probably not suit every taste - the main thing however is surely to try and arrive at something that is both workable and (most importantly) is actually used and adopted by Members when they build modular track.
To me at least, getting my track into my car is probably more important than absolute scale rail lengths, but I may be in a minority?
Any other views out there??
Regards,
Ian
PS "Cabbage" I've just become a convert to 900mm lengths ;)
As you are finding out IanT there IS a reason why I suggested a design grid of 150mm by 900mm. When you start to look at the electrical connection side of it then my reasoning in using that type of connector and wiring -might begin to become clear...
"The only difference between a Madman and Me, is the fact that I am NOT Mad" -Salvador Dali
regards
ralph
Still looking at it Ralph.
Derek, it occurs to me that I have probably not explained one key part of what we've been considering. We have the notion of 'Standard' and 'Custom' C3 modules. The standard modules are essentially simple straight and curved track components and are fairly closely defined. Custom modules (sections if you wish) can be just about anything you want them to be, provided they have at least one C3 compliant connection point. They ideally will be a multiple of the standard modular length and can be split up internally any way (or to any length) you might wish. If you want to 'through' run, then the custom module will need a C3 connection at each end - but those ends can be 20 "length multiples" apart if you want them to be.
So I'm assuming that people will build the level of 'complexity' or prototypical accuracy they want within their own 'custom' sections but will be able to connect them together using simpler (C3) track modules. Our current exhibition railways would qualify as custom modules for instance - provided they have a C3 connection point. So at it's simplest, we could connect existing G3 layouts end-to-end for instance.
Regards,
IanT
Ian.T,
Since you asked for opinions, mine is that rail comes in 3ft lengths and I see no good reason to change from that. Derek makes a good point, but the boards neeed to be as long as can be reasonably handled and for me that's 3ft.
Even our government seem to be stepping back from full decimalisation in some ways.
Mike
Ian,
Returning to the subject of a "Modular Exhibition Layout", as per the Spur II example (or probably more simply a continuous "Test Track" circuit as often seen at O Gauge Shows), what options have you considered for supporting these short modules and at what height - both important points for standardisation.
The latter point is of particular importance if the modules are to be also used for joining 2 separately built Exhibition layouts together.
Derek.
All the European Modular systems (that I've looked at Derek) define it as 1 metre (as measured from floor to rail top - plus or minus 25mm). The US Standards (NMRA) generally use 40" (although 'S' & '0' are set at 42", and tinplate at 36"). However, 40" is 1016mm - so falls within the 1m +/- 25mm range.
So we are planning to use 1 metre +/- 25mm as the standard but we are not going to define the "mechanics" of the legs. Most people seem to use the traditional two upright legs, with cross bracing. I notice that some of the Spur II guys are using a very neat 'table' system that seems to be made of aluminium (see the photos on the link at the start of this thread).
I've been experimenting with a single folding leg - that is kind of hard to describe but the main body is an "I" shape, with two legs at one end that fold out to form an "A". The top of the "I" is about 150mm across and has two 10mm holes that match the C3 connection. They attach to the baseboard using the same bolts that connect the modules together. When folded they are about 600 mm long. You can see the top of one (but not the legs unfortunately) in the AGM photo somewhere in the thread below. I simply used it (on the outside of the module) to hold a makeshift ply "buffer" to ensure the loco couldn't roll off the end of the track.
Hello Ian,
I have to agree with Mike Williams. Cliff Barker's (CB) web site show that his stainless steel rail modules are 3 feet or 6 feet long. If the Associations' brass rail is 3 feet long and so is CB also, why go metric? If we were going to travel to Europe and join up with a German group at a show it might make some sense, but I doubt that this would be so in the near future.
If the European standard module is 1 metre, my response is so what! As the UK and Germany are the only 2 European countries out of the 27 Member states with a substantial following modelling in G3, lets confirm to what the UK needs.
The modules that I made, that you now have, were all 6 feet long because with portable lengths you don't want fiddly end bits ( 6.4 or 3.2 inches) all over the place. I had to drive with the 6 foot lengths stick out of the front car window!
Stacking inside a car is critical and 3 feet is OK for my own car, but not 1 metre.
Perhaps the "Short standard length" should be 3 feet and any other "Non standard length" can be whatever the circumstance require.
regards
So far, score seems to be Imperial 4 : Metric 2 but I suspect there is some way yet to go!
No mention yet of radii.
If the ultimate aim is to join umpteen sections in an exhibition hall, then does there not need to be a specified optimum radius (or radii)? It is unlikely that a straight run of 60 or 80 ft is going to be available, similarly 20ft radius curves are not a practical proposition.
The 'G' scale curves (including those in the 'Spur 2' photos) are very tight, perhaps as little as 4ft radius (or whatever in Metric) and that would not be workable for a 'proper' G3 layout, in fact most locos and rolling stock would not be able to negotiate much less than 8ft and would be happier with 15!
Interested to read Ian.T's specified height of 1 metre + or - 25mm. I assume that means a nominal 1m but provide at least 25mm adjustment up and down?
John is right about standard radii if the idea is taken a stage further with the potential to join boards into an oval. I know Ralph and Ian have discussed this and the equally important chord or baseboard length for curves. Personally I'd go for 12ft or 15ft radius.
Mike
If we assume that we will generally use curved sections to give a 90 degree bend, then the exact radius doesn't actually matter provided there are 'make-up' straight sections at the ends so that the overall quadrant adheres to the 'standard' module size (whatever that is defined as).
Several people have suggested that they could make one (removable) section of their home line to be C3 compatible, and this could work in my proposed line too - but due to their particular constraints they may not be able to use, say 12' radius, but can use 11' 6" - so in their own line they just use their basic boards, and have a couple of 6" extensions to use when joining up with others.
Now, if we want a 'real' railway with transition curves and superelevation, it gets a bit more interesting......... ;D
Andy
I think people are starting to get a little confused here...
The length of a C3 Module is 900mm.
The width of a C3 module is 150mm
The height from floor to rail head is 1000mm +/- 25mm
The size is based on the fact that most common materials (eg wood) are now sold in multiples of 300mm. Thus it made sense to design a module based on a standard length of timber.
VIZ:
A 2400mm length of PSE timber 69mm x 18mm would cost £3.21p from Wickes. This gives me two sides at 864mm, two ends at 150mm, three internal cross pieces of 114mm -leaving you with an off cut 30mm long... I then glue/nail a piece of 3mm thick hardboard on top of it. One £4.37p sheet provides the tops for eight C3 modules. The rail head then sits 16mm from the hardboard. The height of the completed C3 module is (16+3+69) = 88mm. The legs would not be a metre long as the distance from the bottom of the C3 module to the floor would never exceed 937mm.
As to radii and chord distances... I personally favour a curve fabricated on an 18 sided polygonal base -as this makes both the maths and construction easier. There are a few "perfect radii" and "perfect chords" but the first of the perfect radii start at roughly 3.5 metres or 11 feet 6 inches radius. Any "tighter" than that and we could get into some dire constructional stress. I should know as my curves are going to have to be 2.3 metres or 7 feet 6 inches radius and I have had to roll the rail in slips and "jig build" the track to take that sort of bend. As it is I still believe that "Hillmans Railclamps" will have to be used to connect the sections of my curves.
I don't have the C3 spec document on this server, (mine is two time zones west), but I seem to recall a radius system based on multiples of 300mm(?) Which would be handy as the first perfect chord works out as a rough radius of 3.8 metres...
regards
ralph
At the risk of jumping some guns here (I'm awaiting some claifications from Ian's Spur II friend (Torsten) and also I'm mapping out some possible combinations using CAD - I would make the following comments.
Like it or not, the UK (and most of the world) have gone metric. My sons for instance do not "do" Imperial. Already metric fittings are the only ones commonly available. I'm going to specify a metric bolt (not a 3/8ths one) for a mechanical connection for instance. If we are trying to create "Standards" then let's do it in something that is as current as we can make it. It is more likely to be used, and less likely to date.
Cabbage's original point to me was that it did not make sense to "mix" measurements and having thought about it, I agree. The fact that rail length is 3' currently is also really a fairly short term issue, IF we are planning standards that will have a life of 10 to 20 years and possibly more. Both the Society and CB can move to a metric rail length over time - and it's really not a big issue to use 3' in the meanwhile. Two of my 3' sections can have a 171mm extension screwed on one end, and hey presto - I have a 2 metre module. Or as Cabbage argues, use 900mm and cut 14.4mm off the rail (just over 1/2")
Most rail will be continue to be consumed building garden railways and 'custom' sections anyway, where the rail length doesn't matter too much at all in practice. The moment you start to build turnouts, you always end up with all sorts of odd lengths, both used and left over (at least I do). I would also point out that whatever radii curve you decide to use, you will never have a perfect length to fit them, as they will be a 'radial' length (as {I think} Cabbage points out) and my less informed view is that one rail is always longer than the other anyway.
So I'm trying to take a long view and get a solid solution. I don't think we will "join up" with the Spur II guys - but why rule it out? Who knows what will happen - visits to their Schenklengsfeld event - why not?
Oh, and Andy - who said we couldn't do transistions - NEM 113 covers this, although they call them "Easements" . Just seen Cabbage has posted in from abroad. Just to say the Spur II minimum radius for "mainline" is 3000mm and 1500mm for light/industrial railways "in exceptional cases"
Glad to see some interest ;D
Sorry, don't mean to over-do this topic but I've just had an email back from my Spur II friend, Torsten, which I though might be of interest to recent posters here.
The Spur II standard gauge module definition (M24) doesn't give a recommended module length (unlike their NG M22 standard of 660mm). This was one of the questions I asked Torsten to clarify for me. His reply was a bit of a surprise, given that all the module standards I've looked at do define this aspect of their modules.
Torsten say's it's not defined in M24, because it's up to Spur II Members to decide the module length that best suits their transport requirements.....
Well, my interest in Spur II standards was basically because they are (in so many respects) the same as Gauge 3, and they are by far the nearest thing to us in their design requirements (N & Z gauge are a bit removed from G3 after all). It's also pretty clear from the photos of their annual Schenklengsfeld event that they have a great deal of experience in modular GTGs.
So, what to do?
I think I'll sleep on it.
Regards, IanT
On the subject of transition curves, I have built a 30 foot length section at one end of my circuit to overcome problems at "Rumble Corner" so named because Geoff's Crab kept flying off at speed into the leaf bin, upsetting the cat and the frogs, not to mention bending the buffer beam on the Crab somewhat.
The radius is 13 feet which is just about right for a six coupled loco at speed with flanges on all driving wheels. I used varying thicknesses of longitudinal tapered wood section supporting the wooden sleepers under each 3 foot section. If you have plastic track then the same technique can be used, providing there is a gentle lead in to the curve section rising to maximum elevation and a then corresponding gentle lead out to flat and level.
Works a treat and well worth the trouble, also it looks good as the locos "lean in" realistically to the curves.
regs PK
Interesting radius (13') you've used there Peter,
The NEM 113 'Easement' recommendation I refered to below states that "Easements are especially useful on tight curves, whilst they may be ommitted on curves > 60 x G"
So as a 'NEM Rule of Thumb' (in G3 terms) this suggests that in practice, curves above a radius of 3.81 metres (12.5') shouldn't require transitioning. Of course that may not be the same thing as saying it will look right.
For curves under the 60G radius they give various way of calculating the 'easement' but I think I kind of prefer their bent stick - sorry - "Elastic Staff" method best. It seems wonderfully understandable somehow, but I'm sure Cabbage will prefer a more technical/mathmatical approach. ;)
IanT,
The superelevation at differing radii and the formulae to work out transitional curves has already been written up by me for the Technical Manual. All you have to do is follow your finger along the printout...
quote:
"If you can't show the maths then its an "opinion", and not a fact"
unquote:
My late father always had a low opinion of "opinions"...
regards
ralph
A magnificent Dutch modular HO layout (usually seen at the Chatham Dockyard railway show) comes to mind. The individual scenic modules are not all directly connected, but are separated by short(ish) hidden sections. Using this technique, the individual modules can be designed with some latitude.
Why not, therefore, have somewhat flexible connecting sections available for use at 'multi-modular' shows and get-togethers? A lightweight base that opens out like a fan and locks into position, onto which track is laid in situ would suffice for the odd corners that just won't match up otherwise. At worst, a length of track might need to be cut to suitable length at each event, but that's not so expensive given the benefits.
Just a thought. Ted
Would these (or something similar) make suitable supports?
http://www.toolbank.com/p/STA192038?utm_source=Sign-Up.to&utm_medium=email&utm_campaign=180577-Grab+A+Great++Deal+Spring+2010
Advantages appear to me to be:-
1) Supplied ready-made.
2) Lightweight and foldable for transportation but strong (can carry 340Kg)
3) Supports would all be of uniform height.
4) Not too expensive (at the offer price less than 12GBP each).
5) If specified as the 'standard' support, the layout modules could incorporate location points.
Interesting Ralph quotes 11ft 6" or 3.5m (only 5mm difference so suitable for both camps!) as the minimum "perfect radii" because if you scale this back down to O-Gauge it equates to approx 6ft, which is the accepted practical minimum radius for "main line" operation in that scale.
Therefore may I suggest that this then becomes our standard minimum radius for the modules and that we request that CB adds 3500mm to his range of aluminum radius curves.
Derek.
Hello All,
As a newcomer to G3 I am finding this thread quite interesting. A few years ago I was involved in a similar exercise in 3mm scale, and it occurs to me a few points may be helpful. If not, tell me to shut up and go away!
The concept stemmed from the geographical spread of members, and hence the difficulty of having a large layout for GTG/exhibition purposes. I assume this is similar here.
To ensure through running a standard end profile for baseboards was generated including fixing bolt holes, track positioning, and scenery contour for scenic continuity where appropriate. The template was produced in either hardboard or plywood (I can't recall which, but it's not too important) which was circulated to all participants whenever they wanted to build a board. Provided you stuck to this end profile you could do anything you like between the ends. Height was specified from floor to railhead, but your support method was left to individuals as long as it included a method of adjustment.
Thus the unit length, width, track complexity, etc was up to you. The only time length became an issue was when making up a circular layout, to ensure that both sides straight sections totalled the same length - the specific lengths being unimportant. As far as I know the scheme is still in service and is very successful.
Corner units used the same end profile, but the radius was set firmly to ensure any circuits would fit properly.
I think if I was doing it afresh I would use a similar approach, but would have two end profiles, to accommodate either single or double track. A further refinement might be to have a batch of board endplates manufactured by the Society to ensure accuracy. Builders would buy a pair, and then put whatever they wish between them in the confidence that it will all fit together. It does mean that the board ends would be made of a particular material, but if this doesn't measure up to your preferred board construction you only need to screw them to the ends to achieve a fit.
Since absolute length is not critical, if you want to make a large set-up between the standard ends, there is no reason why you cannot make more than one board and use whatever profile you like to join them together.
Cheers,
Tony.
Thanks for the feedback Tony. Yes, part of the motivation is to ease some of the geographical constraints imposed by the 'fixed' nature of garden railways. I wanted something portable and already had some track sections from Peter that were essentially just laid on MDF strips.
The original 'Connect 3' was a laser cut plate that was positioned in relationship to the track-end (rail top) by a jig. The plate had precision cut holes in it that would accuratley line up with another plate on the neighbouring section. We had a small number made up and they were offered out to people for comment. Several changes were made to the design but cost remained a problem. I simplified the design but also decided to look more closely at existing model railway practice.
The Spur II approach is quite similar to the one you describe, although they simply publish the spec. of the module end. There were some aspects I didn't fully understand but with the help of several German friends, their approach is much clearer now and has the advantage of low cost.
I have now written a new draft 'Modular Standard' (well recommended practice really) and there is a Committee Meeting tomorrow (27th) at which I will propose that we circulate this document to interested parties for comment. I would also add that you can build track sections to just about any dimensions you want, but there are advantages to building to a design grid if you want to bring together larger groups of modules from many sources. In turn the design grid tends to dictate what the standard radii are, as you need defined entry and exit points "on the grid".
As you state this, doesn't matter too much, until you try to build circuits where the ends actually meet up. I'll add more here after the meeting tomorrow.
Regards,
IanT
Please keep us posted as I know you will Ian
My apologies for the delay – but here is an update and summary of progress.
To save new readers looking too far back, I have been working with the idea of a "Standard" for both a 'connector' and an associated modular approach to baseboard construction in G3 for some time now. Members will recall my "Connect 3" connector and my modular track lengths last seen at the AGM. The Mk1 'C3' connector was a laser-cut plate that was screwed to the end of modules and was aligned via a 'Jig'. We had some prototypes laser cut and they were distributed for trial. Some comments were returned but to achieve an economical unit, we would have needed a fairly large (and expensive) stocking order. It was probably also over engineered (a weakness of mine).
The photos of the Spur II GTG at the beginning of this thread, prompted me to look again at other modular practice. I had originally been inspired by 'NTrak' (and the oNeTrak sub-set of this) but I looked at work in other scales at the time. This time around, I looked much more closely at the work of the Spur II Group in Germany, which is the nearest equivalent in scale and gauge to G3. The main difference is of course the European vs British loading gauge.
I've used the Spur II (and NEM) standards to start over in some senses, as it seems to me to make good sense to use, what is clearly a good deal of existing practical experience in large scale modular railways. There are differences, as there will always be compromises to be made.
My original modular concept was based on a 36" x 18" grid – but Ralph (Cabbage) suggested we should go metric (see rest of thread below for more info) with a 900mm x 300mm grid. After a lot of thought and a fair bit of lobbying, I've set the basic module size at 900mm x 450mm (min). Spur II use a minimum 500mm (but do not specify length, something I've checked with them, thanks to Torsden). I originally proposed a 1000mm x 500mm but the existing rail is supplied at 36" lengths so this was inconvenient. Using 900mm results in very little rail 'waste' and most rail will be used on custom and curved modules where the rail length is not really a factor. The mechanical & electrical connections specified by Spur II have been adhered to, and in theory, we should be able to connect together should we ever wish to.
In terms of 'standard radii' Spur II do not seem to recommend those either but I feel it is better to suggest some, rather than just have everyone use an arbitrary radius. I initially worked to a standard 900x450 grid to work out how to place the track centre of curved sections in the correct place (to line up with straight modules on the same grid). This gave some strange (irregular) radii to work with. I have therefore decided that my recommendation is to work in 1500mm steps from 1500mm to 7500mm, with sections at 15 degree radials. This does of course ignore the 900x450 grid in the curved sections, but I don't think there should be any issues in practice. Cliff Barker also has turnouts in 4500mm & 6000mm radii. In other words the pro's outweigh the con's.
There were a few other issues but I will not detail them here. Suffice it to say that I believe most dimensions could be selected on an arbitrary basis but that it makes sense for everyone to work to the same ones where possible. Where it isn't, I've introduced the concept of a 'custom' module (which should cover just about anything people want to do).
On Saturday, I presented the "M 01 G3 Module Standard" to the Committee and proposed we circulate it to a small group of experienced G3 Exhibitors/Members for commentary and review. I have also been previously asked by other Members for early access which I am pleased to do.
I should finally state that no-one authorised me to undertake this work. It is entirely my own initiative and I have borrowed heavily from others (most particularly Spur II). So I have no authority to dictate module standards. However, I do intend to build modules for my own use, as do others I have spoken to. It therefore seems to me, to be advantageous if we can work to some common dimensions and thereby improve the versatility of what we are building. My requirement is primarily for a portable test track that I can store away and eventually take with us when we move. Others will be more focused on a scenic approach and I hope that I have considered their requirement in composing this recommendation.
I have asked our Webmaster to make the draft M01 PDF document available for download by Members for their consideration. If any non-Society Member is sufficiently interested, please contact me directly for a copy.
Note : Document referred to above deleted 22.10.2010 and replaced by updated version...see later message.
This document is a lot better than the previous one. It now shows method and means, plus the fact that everything is based on modules and units. I personally would prefer something rather mechanically more robust than M8 ring solder tags to electrically join / bond track with -this puts me firmly into the plug and socket group(!) I also think that there should be a set of secondary location points towards the edges of the module -just a couple of M5 nuts and bolts to stop wobble.
But it is definitely a usable document.
regards
ralph
With respect to the electrical connection Ralph, the Spur II guys do run 2-rail using this same system. They specify 24V DC (20v effective on the Loco) at 10A max. They also specify a "0.75cmsq area wire" which sounds kind of heavy duty to me though (4.89mm radius?) but perhaps you would take a view on it. It has the advantage of being both simple and cheap.
However, I was pretty sure that some would want a better method, so I left that particular door open.
For myself, I'm only planning on using battery electric or live steam at this time, but I still went for this approach as a simple 'track bonding' idea. If you want to refine your suggested 'plug & socket' proposal, I'll write it up with the other 2-rail stuff that still needs defining, like track polarities, loco direction etc.
I think the two M8 bolts at 122mm spacing are fine for the single track module at a 450mm (or even slightly more) width. If you go twin track, then you have another set of M10 holes at a 385 mm centre from 'front of module', again sufficient (I feel) for a module 610mm wide. If properly supported, there should not be too great a strain on the mechanical connection.
For very wide modules (with just one track connector) I suspect people will just use an 'C' clamp - this is after all what most of the smaller gauges use just on their own (i.e. no through bolting at all). The standard doesn't disbar this solution, whereas it would be hard I suspect to define all the hole combinations that might otherwise be required.
Thanks for your feedback
PS I'm going to be off-line for a while, so will be (unusually) quiet for a bit. :)
Ian T,
I still think that 3 pin XLR connectors are the correct solution. The other is the DIN plug -but that is not self locking-and the current capacity is too low really. I would happily push 200 Watts through an XLR -but blanche at 5 watts through a plastic DIN plug. I did propose that the XLRs be wired "straight through" in that the centre pin was dead and the two other pins mirrored the track lines. Ideally they should be wired in Blue and Yellow cables -but I suppose you could use Black and Red....
The cable specs from the Spur II group are a mystery(?) as they should be an EU std spec in that it is number of conductors and thickness in mm viz: 10/0.1 (10 conductors of 0.1mm). The cable area they specify is thicker than the starter motor cable on my speakers... I can only assume that something somewhere has slipped a few decimal points!
The nearest thing that I can "translate it" to is a 75/0.19 cable which is rated at 20 Amperes -which would fit in with the 10 Amperes current (+100% overload).
Have a nice holiday -I am going to spend mine in the shed!
regards
ralph
The doucument was pretty good for me...