Modular exhibition layout

[John Candy]

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.

[Derek King]

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.

[trammedic]

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.

[IanT]

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
   

[keith Bristol]

Please keep us posted as I know you will Ian

[IanT]

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.

[cabbage]

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

[IanT]

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.     

   

[cabbage]

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

[keith Bristol]

The doucument was pretty good for me...