Templot Club forums powered for Martin Wynne by XenForo :

TEMPLOT 3D PLUG TRACK - To get up to speed with this experimental project click here.   To watch an introductory video click here.   See the User Guide at Bexhill West.

  • The Plug Track functions are experimental and still being developed. Some of the earlier pages of this topic are now out-of-date.

    For an updated overview of this project see this topic.   For some practical modelling aspects of using Plug Track see Building 3D Track.

    The assumption is that you have your own machines on which to experiment, or helpful friends with machines. Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful.

    Some pages of this and other topics include contributions from members who are creating and posting their own CAD designs for 3D printing and laser-cutting. Do not confuse them with Templot's own exported CAD files. All files derived from Templot are © Martin Wynne.
  • The Plug Track functions are experimental and still being developed.

    For an updated overview of this project see this topic.   For some practical modelling aspects of using Plug Track see Building 3D Track.

    The assumption is that you have your own machines on which to experiment, or helpful friends with machines. Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful.

    Some pages of this and other topics include contributions from members who are creating and posting their own CAD designs for 3D printing and laser-cutting. Do not confuse them with Templot's own exported CAD files. All files derived from Templot are © Martin Wynne.

N gauge "standards", 4mm narrow gauge and mid-life crisis!

Quick reply >

Paul Boyd

Member
Location
Loughborough, UK
You may be aware that I'm currently building a layout to a track standard I'm calling S4n2 - 7.83mm gauge, using 2mm Scale Association track and wheel standards. This is going well, except... I'm simply not getting locos finished fast enough because of the time taken modifying kits to these standards - something I enjoy but we all have a finite lifespan! Also, when I started this project 20+ years ago (!!), the idea that one day there would be excellent RTR 009 stock available would have been laughable. I'm reluctant to even attempt to modify the RTR 009 I do have to S4n2. So, I'm doing a feasibility study on effectively starting again but using N gauge standards...

Ok, there aren't any! Well, there seem to be two actual standards - NMRA and NEM. I've downloaded and digested both standards for track and wheels for 9mm gauge. Essentially, NMRA B-B is 7.55-7.7mm, span 7.44-7.52mm (they don't really like mm, but inches to 3DP gives equally silly numbers). NEM-310 B-B is 7.4-7.6mm, span 7.2-7.3mm. Flange thickness for both is (or can be) 0.5mm. Measuring wheels seems to suggest the following:-

Bachmann 009 is nearly NEM, depending on the loco and specific wheel set.
Heljan 009 is NMRA-ish (but large variations across five axles of the same loco!)
Peco 009 bugboxes - none of the above.
Dapol N gauge seems to be NMRA (and they state this for newer models)
Farish N-gauge is sort of NEM-ish.
Dundas etc 009 kit wheels can be adjusted for NMRA or NEM.
Backwoods Miniatures loco kits have a mixture of wheels even between different boxings of the same kit - fortunately I kept the kit wheels but some are too coarse.
Most flanges are 0.5mm thick. Some are 0.6mm which complies with NEM but not NMRA.

I intend to build my own track as there's no way I want flangeways and crossing gaps you could lose a loco in. This will almost certainly mean NMRA standards, and I'm going to grit my teeth over the gauge discrepancy for 2ft narrow gauge. It will also mean that much unmodified RTR 009 won't run on it because of the too tight back-to-back gauge.

How do the N-gauge people handle this utter mish-mash of different track and wheel standards? Does anyone build their own track to either of the above standards? If so, it looks like NEM might be the better option. I've not yet joined the N Gauge Society although I intend to for another project. I've browsed this forum and the archive, and I'm aware of the Finetrax standards used but I'd prefer to use a recognised standard. I'm also quite happy turning my own gauges as necessary.

I'm not averse to shoving wheels out on axles for RTR stuff, and more gritting of teeth to rebuild those locos and chassis that I've built to S4n2. Some of the built S4n2 track will get reused on a small 'Borth-y-Gest' style layout I have in mind so I won't abandon that scale altogether.

Finally, if I go ahead with this using NMRA 9mm gauge standards, it isn't 009! Calling it 009 implies I could take an RTR 009 loco out of the box and run it, but that may not be true except on plain track. What should it be called? I feel there should be a '4' in the name somewhere!

Cheers,
Paul
 
_______________
message ref: 5857
@Paul Boyd

Hi Paul,

I long ago gave up trying to make sense of the N gauge standards. You would think that the N Gauge Society would publish something, but I never found any.

But I don't think it's a good idea to look at standards from the wrong scale, even though it's common practice in n.g. modelling.

Ignore N.

If you are modelling in 4mm/ft scale the obvious starting point is some 4mm/ft standard, and modify it to suit the wheels you are using. If the flanges are around 0.5mm - 0.6mm they would run quite nicely on EM-SF with 0.8mm flangeways. That's 18mm gauge, so if you just subtract 9mm from everything you get your 9mm gauge. What's more you could then build mixed-gauge track with EM-SF if you wished.

The back-to-back for EM-SF is 16.5mm - 16.6mm, so subtracting 9mm gives you 7.6mm back-to-back max. 7.5mm min. How does that look?

With 0.8mm flangeways and a 0.25mm blunt nose, the wheel width needs to be 1.85mm min, say 1.9mm to be safe. How wide are they? You could maybe reduce the blunt nose width to 1/2" scale for lighter n.g. loads if necessary.

As to what you call it, how about 4n27 ?

You could maybe try asking the 009 Society: https://009society.com

But I can't find any standards on there either. They do have a members' forum which might have some ideas.

All the best with the project. :)

cheers,

Martin.
 
_______________
message ref: 5861
@Paul Boyd

Hi Paul,

I long ago gave up trying to make sense of the N gauge standards. You would think that the N Gauge Society would publish something, but I never found any.

But I don't think it's a good idea to look at standards from the wrong scale, even though it's common practice in n.g. modelling.

Ignore N.

If you are modelling in 4mm/ft scale the obvious starting point is some 4mm/ft standard, and modify it to suit the wheels you are using. If the flanges are around 0.5mm - 0.6mm they would run quite nicely on EM-SF with 0.8mm flangeways. That's 18mm gauge, so if you just subtract 9mm from everything you get your 9mm gauge. What's more you could then build mixed-gauge track with EM-SF if you wished.

The back-to-back for EM-SF is 16.5mm - 16.6mm, so subtracting 9mm gives you 7.6mm back-to-back max. 7.5mm min. How does that look?

With 0.8mm flangeways and a 0.25mm blunt nose, the wheel width needs to be 1.85mm min, say 1.9mm to be safe. How wide are they? You could maybe reduce the blunt nose width to 1/2" scale for lighter n.g. loads if necessary.

As to what you call it, how about 4n27 ?

You could maybe try asking the 009 Society: https://009society.com

But I can't find any standards on there either. They do have a members' forum which might have some ideas.

All the best with the project. :)

cheers,

Martin.
@Martin Wynne

Hi Martin,

I suppose I was coming from the starting point of N gauge and 009 being effectively the same as far as track and wheels go and not really considered looking at 4mm scales, especially as 2mm Scale Association standards work very well for 4mm scale 2ft narrow gauge :)

EM-SF less 9mm is certainly food for thought, and the numbers work very well. Wheels are mostly around 2.0mm wide, some about 2.3mm, some in Backwoods kits a rather astonishing 2.6mm (hidden by inside frames though). 7.5 - 7.6mm back-to-back is fine. Being able to deal with flanges between 0.5 and 0.6mm will save skimming thicker ones down. Yep, that does all work rather well! I'm a member of the 009 Society but also haven't found anything there regarding track and wheel standards - it simply doesn't seem to be a consideration.

I'll be building a sample bit of track with a turnout and an appropriate chassis before finally deciding. I've put a lot of time and effort into my current layout to then try something else that I find doesn't work. A critical factor for me (apart from running qualities, of course!) is appearance. I'm just hoping I can get my head around the extra 3" on the track gauge!

Talking of the extra 3", it took me far longer than it should have done to work out what the '27' in 4n27 stands for!

Thanks for the thoughts - I'll keep you up to date with progress.

Cheers,
Paul
 
_______________
message ref: 5862
@Paul Boyd

Hi Paul,

I long ago gave up trying to make sense of the N gauge standards. You would think that the N Gauge Society would publish something, but I never found any.

But I don't think it's a good idea to look at standards from the wrong scale, even though it's common practice in n.g. modelling.

Ignore N.

If you are modelling in 4mm/ft scale the obvious starting point is some 4mm/ft standard, and modify it to suit the wheels you are using. If the flanges are around 0.5mm - 0.6mm they would run quite nicely on EM-SF with 0.8mm flangeways. That's 18mm gauge, so if you just subtract 9mm from everything you get your 9mm gauge. What's more you could then build mixed-gauge track with EM-SF if you wished.

The back-to-back for EM-SF is 16.5mm - 16.6mm, so subtracting 9mm gives you 7.6mm back-to-back max. 7.5mm min. How does that look?

With 0.8mm flangeways and a 0.25mm blunt nose, the wheel width needs to be 1.85mm min, say 1.9mm to be safe. How wide are they? You could maybe reduce the blunt nose width to 1/2" scale for lighter n.g. loads if necessary.

As to what you call it, how about 4n27 ?

You could maybe try asking the 009 Society: https://009society.com

But I can't find any standards on there either. They do have a members' forum which might have some ideas.

All the best with the project. :)

cheers,

Martin.

Hi Martin,

Well, I've made one decision - 4n27 (EM-FS minus 9mm) it is! I've been playing with Templot this afternoon, after a walk around Mount St. Bernard Abbey with a friend. I've made a copy of the last S4n2 box file in a new folder to convert to 4n27 and experiment with, especially reminding myself about converting gauges and settings.

I still need to decide if this whole crazy project is what I really want to do though. I've printed off a section to do a test build (which may eventually be incorporated into the "new" layout.

Cheers,
Paul
 
_______________
message ref: 5873
I did this as an experiment last year. It's to S scale. It represents 3ft gauge (14.28mm). The (rusty) wheelset is actually P4 but regauged S society wheels worked just as well.
 

Attachments

  • IMG_1251.jpg
    IMG_1251.jpg
    737.5 KB · Views: 64
  • IMG_1253.jpg
    IMG_1253.jpg
    395.3 KB · Views: 61
_______________
message ref: 5926
I did this as an experiment last year. It's to S scale. It represents 3ft gauge (14.28mm). The (rusty) wheelset is actually P4 but regauged S society wheels worked just as well.
Looks good (apart from the rust 😂)

Visually though, if the back of the RH wheel was against the check rail, it looks like the LH wheel flange might clout the crossing nose. I guess you’ve checked that though.

Cheers,
Paul
 
_______________
message ref: 5927
It's a start! 9mm gauge, 0.8mm flangeway, and the 2mm wide wheels from Dundas kits have a 0.5mm flange with back-to-back adjusted to 7.6mm. i.e., 4n27! What I was keen to check was how the wheels behaved over the crossing nose and I was really pleased to find that they just glided across the gap without any noticeable jolt or dip, or any inclination to take the wrong road.

At the moment I'm working with flangeway gauges cut down from a 0.8mm feeler gauge and a 9mm block gauge very carefully filed down to 9.0mm over about a 20mm length. I feel lost without check rail gauges! Before I get too carried away, I guess I'll need to turn up a selection of roller gauges.

Sorry about the grubby track - it's far too early to clean under the tap so the neutralising rinse has just been sloshed over, attracting dirt as it does so!

IMG_0880.jpeg
 
_______________
message ref: 5970
Hi Paul,

That's looking very promising. :)

Also good to see the symbols function in use on the template -- droppers and gaps.

I see you are using FB rail, and you have printed a FB template with the rail foot lines. Do you find them helpful in aligning the FB rail? There are several features such as this in Templot for which I rarely if ever get any feedback. So I assume it just works. But I do wonder if there are any improvements which could be made -- I know for example that the FB switch planing isn't properly represented on the FB templates. If plug track ever gets to doing FB baseplates and fixings, the FB rail functions in Templot will need a fresh look. At present the way it's done is all a bit of a kludge.

cheers,

Martin.
 
_______________
message ref: 5971
Hi Paul,

That's looking very promising. :)

Also good to see the symbols function in use on the template -- droppers and gaps.

I see you are using FB rail, and you have printed a FB template with the rail foot lines. Do you find them helpful in aligning the FB rail? There are several features such as this in Templot for which I rarely if ever get any feedback. So I assume it just works. But I do wonder if there are any improvements which could be made -- I know for example that the FB switch planing isn't properly represented on the FB templates. If plug track ever gets to doing FB baseplates and fixings, the FB rail functions in Templot will need a fresh look. At present the way it's done is all a bit of a kludge.

cheers,

Martin.
Hi Martin

It feels promising! I also feel happier that I can get loco kits built more quickly (maybe at the rate of a melting glacier!) knowing that I don't have to spend a lot of extra time with the finer scale.

I print out full size wiring templates for each baseboard so having the symbols is very useful for making sure I don't put some under-board gubbins where a wire needs to drop down, or forget to cut an insulation break, or realising on the screen that an insulation break would be better somewhere else before cutting rail. I also have a wiring schedule for each board, so I need to know where wire 54 or whatever is on the track! As well as that, I have a full size scenery printout and similarly I can make sure things aren't going to clash or become inaccessible. Maybe you should remind people about the symbols on a Tip Of The Day!

The rail foot on the printed template is essential to my mind, otherwise the rail foot would hide the rail head position on the template. Things like switch planing I do by eye anyway so I don't see it as essential on the template. I don't like working with FB rail but on this layout the main line and the platform lines are FB with the rest being BH. The rail foot keeps getting in the way!

Cheers,
Paul
 
_______________
message ref: 5972
Maybe you should remind people about the symbols on a Tip Of The Day!
Hi Paul,

Thanks for the feedback.

I did a Tip of the Day on the symbols last year, but I will perhaps do another one soon:

https://85a.uk/templot/club/index.php?threads/tip-of-the-day-construction-symbols.451/

Maybe we need a function to put a random Tip of the Day link somewhere?

We did actually look at the symbols in the final part of last week's Zoom meeting -- see Part 7 at:

https://85a.uk/templot/club/index.php?threads/zoom-meetings-recordings.621/post-5940

To answer my own question in the meeting, the symbols were new in version 227 of May 2021.

(Next Zoom meeting tomorrow 22nd Feb, 8pm, all welcome.
Access details: https://85a.uk/templot/club/index.php?threads/zoom-meetings-access-links.620/latest )

cheers,

Martin.
 
_______________
message ref: 5973
Well, I don’t reckon that looks too bad! At least, it won’t once it’s cleaned up. I’d forgotten how awkward crossings are without decent gauges! I think I’m set on this, so after the switches are in and I’ve cleared a bit of bench space for the lathe at work the gauges will be next.

Talking of switches, as this is a curviform crossing, the turnout road switch blade/closure rail will be made from the same pre-curved length as was used for the closure/wing rail - this should give a smooth continuous curve right through. The main road is straight.
 

Attachments

  • 45EF4D03-E4DE-4EAE-976C-D2BBAEA510B3.jpeg
    45EF4D03-E4DE-4EAE-976C-D2BBAEA510B3.jpeg
    3.1 MB · Views: 70
  • 3B90313C-CF9C-4EF9-8E14-93F29991846F.jpeg
    3B90313C-CF9C-4EF9-8E14-93F29991846F.jpeg
    2.6 MB · Views: 59
_______________
message ref: 5977
I think this clinches it! The Backwoods Miniatures Quarry Hunslet kits have half-etched cut-outs in the frames to be removed "if you wish the locomotive to go round curves" - there was no way I was going to do that. My self-imposed minimum radius is 18", and in fact I don't think I've got anywhere near that - the turnout in the photo has a minimum radius of 46", for instance. The only way to check was to quickly build a chassis using a spare kit and a short length of test track and just try it! With a 7.6mm back-to-back, the driving wheels are a snug fit in the frames, but weirdly the pony truck needs slimming down! In the close-up photo, the chassis is skewed on the rails in the "wrong" direction, but even so there's just clearance between the pony wheel and the frame. A bit of side control will make this work nicely, and in the overview photo with the chassis more or less straight on the rails, you can see there's a lot more clearance.

So... the fact that I built this chassis using the kit wheels (albeit using narrower 2mm wide pony wheels) without having to faff about ordering tyres, making centres, modifying the gearbox etc was actually quite exciting! The only change I've made is to correct the pony truck pivot location. After all, being able to speed up build time was a prime motivation, as well as being able to run RTR stuff with the wheels just pushed out a bit.

I need to mull all this over for a while. There's a hell of a lot of already built and laid track that has to come up, some of which will be re-used elsewhere, and I would also take the opportunity to re-lay it on cork instead of Carr's foam underlay. There's also a load of loco chassis to rebuild, including the FR/DHR Garratt which will no longer be split frame with CSB suspension! Rolling stock is relatively straightforward although I will need to re-draw the carriage bogies to be a bit wider.
IMG_0908.jpg
IMG_0910.jpg
 
_______________
message ref: 6044
Back
Top