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A few quick finescale track queries


RichardJones

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First off I'll just clarify I'll be building to 9mm gauge, not 9.42 as I'm actually modelling the Festiniog Railway in 4mm scale - but it just so happens that code 40 bullhead track is just the thing! (Not to mention split frame chassis bits!) I could go all finescale and build to a shade under 8mm, but I'd like the option of running my stock on others' layouts and vice versa.

 

Anyway a few quick questions concerning practical application of 2mm Association track bits:

 

First off I assume that building the plain track on PCB sleepers using pointwork chairs is going to be the order of the day, IE tehre are not ready made sleepers for 9mm gauge?

 

Minimum radius - is is affected much by the use of finescale wheels? I note the standard calls for 0.1mm gauge widening on bends less than 24" radius - my minimum will be 12".

 

Point construction - I need only the one point luckily but am going to need to pick someone's brain regarding geometry for it and how to convert it into 9mm gauge. Any pointers on working out the dimensions?

 

I think that's it for now, I'm sure there was something else but I guess it can wait!

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Hi Richard,

I've been looking into doing the same. There are jigs available from a member of 2mmSA for making their Easitrack to 9mm gauge. (I'm sure that someone who actually knows who to contact will be along soon). You may also be interested in this thread at another forum you may not normally follow (I assume that it's ok to link to the competition Mr Moderator!):

http://www.ngaugeforum.co.uk/SMFN/index.php?topic=3280.0

This discusses a project to develop an easy to build, fine(ish) scale track system in 9mm gauge.

 

Although, if you're happy to solder then easitrac parts might be the quicker route for you. There are several threads on here about this:

http://www.rmweb.co.uk/community/index.php?/topic/46854-n-gauge-rtr-track-accuracy/page__st__25

http://www.rmweb.co.uk/community/index.php?/topic/29361-n-gauge-track/

Many others come up with a search for "9mm easitrac" on this site.

 

Good luck!

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Richard,

 

First thing you need to decide, particularly with your compatibility statement, is which track and wheel standard are you using ?

I suspect that most 009 layouts use N track at the widest flangeway clearances, with space to accomodate wheels of quite narrow back-to-back and with quite fat flanges. Adopting 2mmFS track and wheel standards, even with the gauge altered to 9mm, is likely to produce stock which won't run reliably through such 009 turnouts.

 

I can't tell whether the 9mm Easitrac parts would help. As I understand them, they use the clearances of the NMRA (US) N gauge specification. This has a slightly wider back-to-back than much older N, and also uses smaller flanges than early N gauge.

 

 

Once you've decided on the track/wheel standards, then you can start to work out the geometry limits.

The minimum curve is dependent on the wheel standard, and the longest wheelbase (particularly anything with 3-axles). A secondary issue with tight curves is the overhang so that buffers and couplings line up. But, your prototypes ran over sharp curves, so were designed with short wheelbases, limited overhangs, etc., so should be able to go round quite tight curves.

Finally the turnout geometry is derived from the wheel specification. Once you've nailed the wheel standard, the turnout dimensions follow.

 

Sleepers are the easy bit - what dimensions does your prototype use ? Then get the nearest size you can to what you need, possibly slightly longer to allow for your increased track gauge (so the bits at the end stick out the right distance).

 

 

 

I am currently proof reading a very thorough book on model railway track construction. Hopefully it will see publication this year.

 

- Nigel

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cheers folks, I will dive into an easitrac search on the forum and see what else crops up - Google didn't throw up an awful lot elsewhere unfortunately.

 

My stock is all going to be built to 2mm association spec using their wheels for locos and some rolling stock, the remaining wheels are those that Parkside Dndas market as their own (but are I think actually Romford or Markits and I think are RP25 spec - wide tread but fairly dainty flanges)

 

Locos are all 4 wheeled (or multiples of 4!) The only 6 wheeler is a Cleminson open wagon which will most definitely not be using prototype articulation or it'll be straight off the road!

 

I have downloaded Templot and tried it, so far no joy, it's a tad mind boggling! I need to do a lot more research on that too!

 

Cheers again folks!

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Richard

Although modern N gauge stuff has reasonably fine wheels and it sounds as though the 009 ones you will be using are reasonable too, however some 009 stuff such as the old eggerban stock may well have deeper flanges. So long as you don't want to run such stuff no problems.

The plastic easitrac bases are to 9.42mm N gauge stock runs fine on it and its only the turnouts where there are problems. The issue for you is the sleepering will be all wrong both in size and spacing. You could use PCB trackwork, true you don't have the chair details but look at the photos of Jerry's Highbury colliery to see how effective it can be. I think if I was you I would consider using the Versaline system where the track is soldered and cosmetic chairs can be added. There is a revised 2mm Track section of the handbook in the pipline, addmitedly it will not really cover building 4mm NG track but will explain the various 2mm track systems.

The jigs for 9mm would be handy The ones I knew of were for the crossings. These are not essential I made N gauge track using a small wooden gauge block filed to size. Crossing Vs can be made using a jig of panel pins in a block of wood. Similarly you do not need to use templot or buy in templates. It is fairly simpe to draw a few construction lines for yourself. I lay the timbers at key points then fill the rest in by eye with a piece of card marked with the spacing to help. This would assist you as your timbers and spacing will be non standard. This is covered in an article for the 2mm Mag which is awaiting publication. I could send you the key bit if you cannot wait.

For the narrow gauge I suspect the turnouts will be straight switches. The only key dimension required are the Lead or the distance from the blade tips to the crossing and the crossing angle. One thing is that trackwork is gauge dependant altering the gauge distorts the geometry thus a FR point scaled down for 8mm at 4mm:1ft should actually be scaled at 4.5mm:1ft for 9mm gauge. However since trackwork came in different sizes things can be fudged a little.

Don

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  • 2 weeks later...

Cheers again folks, I'm now a 2mm association member and am eyeing up what to buy first! Having done some more thinking about building track I've deiced that perhaps I shoudl reverse order my projects and built the 2mm FS Cambrian layout first, the thinking being that yes I'll still need to build everything myself - but the jigs and gauges already exist!

 

Meil, as much as I love what Paul Holmes did, I'd sooner stick to 9mm gauge for NG - that extra mm between the frames is a godsend! IMy current loco designs all utilising 6mm diameter coreless motors driving planetary gearbxes and secondary worm reduction, and all sat between the frames! The design for the England locos even allows for a flywheel (though what use it'll be is unquantifiable as yet!)

 

Anyway I'm digressing from the subject....

 

So in summary I've revised the flight path to be:

 

1) Build some easitrac to 9.42 (Dead easy)

2) Build some 9.42mm points (should be manageable, tehre's enough guides and jigs about)

3)Build a ridiculously small fleet of locomotives

4) Build some track to 9mm gauge from 2mm association bits

5) Build some (in terms of model size) much larger locomotives!

 

Thanks everyone for the input, my knoweledge of track is building up quite nicely now.

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