Track Jigs

[NDHAERO]

Hi all,

I am very new to the World of P4, so this may be a naive question.

I am an engineer by training, so am trying to think of solutions to problems. This is all theoretically thinking so far, I have yet to even get any track, let alone try laying it.

But, my thought today, was why leave it to chance? I live in Beeston, and the Nottingham Tram Extension has been built. They performed all their lengths of track off site, and then laid them directly in position. So I thought why don't they perform them in the model world? Surely it would not be difficult to make a jig, that holds the rails exactly parallel, that could then be curved as one whole? This would create exact parallel rails, and the differentials of the outer rail, compared to the inner, would not be an issue. I am not suggesting mass made commercial rails, but if the jig was flexible enough, it would be used to make any rail formations you chose.

The major issue, would be the elastic deformation of the rail. I.e. what spring back they would have once removed from a jig. This could be solved by either mathematical or empirical methods. Depending on the accuracy of the jig, highly accurate rails could be made, and then just layed.

I am certain in the 200 years of railway modelling all sorts of jigs have been made, and failed. Or am I missing something very fundamental?

In an ideal World, I want whatever I am making, impossible to get wrong. In the aeronautical World, I am used to highly accurate 3 dimensional shapes formed in metal, Rail formations are only 2d so surely there must be a better way than a Back-to-back gauge?

Anyway, I'll be very interested in your thoughts. I am going to have a go at designing one, so any know pit falls etc would be very helpful.

Many thanks,

Nick

[grovenor-2685]

Nick,
You don't use a back to back gauge when making track .
Various sorts of jigs have been tried with varying levels of success. The most common is to use prints (templates) to build on. This is straightforward using track gauges. There are detailed explanations in the Protofour Manualand in the Scalefour digest, and here.
One of the benefits of DIY track is that you can replicate the endless variety of the prototype, not be stuck with what a commercial supplier chooses to supply.
Most of the jigs tried out only become cost or time effective if you are making a lot of identical sections which defeats the above benefit.
Of course if you can come up with a flexible and effective jig system, go ahead, it could be very popular.
Regards
Keith

[Barry Davis]

Hi Nick,

I have always used a jig when making lengths of track. From day one, the first thing I did was make a jig for making half metre lengths of curved or straight track, which has stood the test of time as I am still using it some forty years later.

The jig has spaces for enough sleepers to make two scale 60 foot lengths of track. On one side of the wooden board is a brass straight edge which allows me use the BB gauge to position one rail on to the sleepers for curved track, or for straight track use the BB gauge on the first rail again to position the second rail.

A jig certainly speeds up track constriction, some times its quicker to batch make 5 or 6 lengths of scale 120 foot rail in one hit and have 4 or 5 lengths spare and ready for the next tracking job.

Hope this helps

Barry

[Jol Wilkinson]

Hello Nick,

I did the same as Barry, designing a laser cut "comb" with the correct sleeper spacing for LNWR 60' track panels. I stuck two onto a plywood backing to make two panel sections. For curves I only fitted one rail and chairs, adding the other rail when installed.

The jigs were cut for me by Brian Lewis of Timber Tracks, but there are others who can readily do it.

LNWR track panel jig P4.pdf

The trackwork was designed with Templot and the points built onto the printouts. The whole lot was then assembled in situ.

London Road 1.jpg

Jol

[Winander]

Surely it would not be difficult to make a jig, that holds the rails exactly parallel, that could then be curved as one whole? This would create exact parallel rails, and the differentials of the outer rail, compared to the inner, would not be an issue.
Nick

An interesting idea but if you are suggesting either making curved track in a flexible jig that is curved, or making straight track in a jig and then curving it, this would not allow for gauge widening. The society's track gauges are triangular and accurately widen the gauge when curved track is constructed on a curve i.e. not built straight then curved. That is probably the reason Jol only lays one rail in his jig for curved track.

I am not sufficiently experienced to know if gauge widening is always required - it must depend on radius primarily, and numerous other things besides.

I use functional plastic chairs on ply sleepers and one thing I have been experimenting with is to make straight track with the sleepers nearly touching, then slide them along to their correct positions using a template for accuracy.It appears to work but the risk is that when sliding the complete sleeper with chairs, the chairs are deformed and not as effective as they might be. The advantages are that it is much simpler to get the rail uniformly level as all the sleepers for a meter of rail only occupy 30% of the rail length (on my railway) and it is easier to weigh down as is recommended for this type of construction.

regards

[Alan Turner]

The jig shown by Jol is fine for soldered rivet construction but in my experience does not work well if using functional plastic chairs, simply because removal from the jig to the layout results in movement.

If using functional chairs by far the best way is to build in-situ using track templates; either downloaded from the S4 site or use TEMPLOT.

Regards

Alan

[Noel]

The major issue, would be the elastic deformation of the rail. I.e. what spring back they would have once removed from a jig. This could be solved by either mathematical or empirical methods. Depending on the accuracy of the jig, highly accurate rails could be made, and then just layed.
Nick

For anything other than gentle curves, it is generally regarded as sensible to curve each rail separately to an approximation of the required radius before gluing, soldering or whatever to the sleepers, especially in point work, as it is otherwise likely to present problems. If left straight, it will leave stresses in the track which may surface later, especially if it is subject to temperature variations. Trying to curve complete straight track panels [ie with both rails fitted] other than to a large radius is likely to introduce serious distortion and/or damage the rail fixings as well as narrowing the gauge. How you build your track depends, partially at least, on what you are trying to achieve: a main line, a branch line or limited space industrial track. Some of the latter in real life had very small radius curves and serious restrictions on what stock could be used.

The need for gauge widening depends on what you are running and the radius of the curve. A 16T mineral or other swb wagon, or a bogie vehicle, will need rather less widening for a given curve than a BR 9F 2-10-0, for example, and will go round a sharper curve than the 9F as well.

Noel

[grovenor-2685]

Before templot I used to make half track by jig as described by Jol and others then lay the second rail in situ. Since templot I print out the required curve with transitions etc and then build on the print before transferring to the layout.
I find this gives higher accuracy than putting in transitions by eye which quite often resulted in a tight radius spot near the apex of the curve.
This is using soldered construction which holds its shape when removed from the template. If using cosmetic chairs I think I would retain the template so it held the alignment while transferring to the layout then bury the template under the ballast.
Regards
Keith

[Jol Wilkinson]

The jig shown by Jol is fine for soldered rivet construction but in my experience does not work well if using functional plastic chairs, simply because removal from the jig to the layout results in movement.

If using functional chairs by far the best way is to build in-situ using track templates; either downloaded from the S4 site or use TEMPLOT.

Regards

Alan

Alan's comment re plastic chairs is valid, but if you paint the rail before you remove it from the jig (which saves doing it in situ) the chairs/sleepers stay in place.

[John Bateson]

I use a jig to make up lengths of track. A length of masking tape across the top and a gentle lifting action allow me to transfer the sleepers to a previously drawn line on the track base, using the holes in the sleepers as a guide.
Then a length of a ruler across the top of the sleepers with a modicum of downwards pressure allows me to remove the masking tape leaving the sleepers correctly spaced ready for chairs etc.
I find this works neatly for curves as well as straights.

[Simon_S]

The jig shown by Jol is fine for soldered rivet construction but in my experience does not work well if using functional plastic chairs, simply because removal from the jig to the layout results in movement.

Take a look at some real track - you'll probably be surprised how unevenly spaced and out of parallel the sleepers are

Cheers,
Simon

[Alan Turner]

The jig shown by Jol is fine for soldered rivet construction but in my experience does not work well if using functional plastic chairs, simply because removal from the jig to the layout results in movement.

Take a look at some real track - you'll probably be surprised how unevenly spaced and out of parallel the sleepers are

Cheers,
Simon

I do so every week-end as apart of the SVR permanent way gang. It's not that uneven - we do take some pride in it!

And no we don't use a jig to build 12" to Foot track either. When you are up close and personal to real track it's suprising the details you notice as well.

regards

Alan

[dal-t]

And no we don't use a jig to build 12" to Foot track either.

But some railways did - see around 4:15 here. And if I want to get it "all right" when it comes to putting my jig-built panels down, who does scale versions of the expansion pieces shown at around 10:25?

[grovenor-2685]

who does scale versions of the expansion pieces shown at around 10:25?

Not sure what you mean here, at 10:25 they are assembling a standard fishplate joint. This is rail in 60ft lengths and the gap between rail ends at fishplates is set according to the temperature, the little gadget put on the rail end when bringing the rails together is just a guide to setting the gap and will be removed as soon as the fishplate is bolted up ready to be used again on the next joint. The fishplates are available etched or plastic, the plastic ones have there own built in spacer, the etched ones you can just use any convenient bit of paper or card to space the rails.
Or was the whole question TIC?
Keith

[dal-t]

Or was the whole question TIC?

Well, it was mostly, but I have occasionally wondered how you calculate what the gap should really be - presumably based on ambient temperature at time of laying and length of rail to the next gap. And the spacers the gang were using don't seem to be removed - around 11:55 you see one still in place as a fishplate is bolted up, and a few seconds later the platelayer is knocking it sideways but still wedged in the gap. I suppose it falls out next time the temperature drops enough - 1947 Big Freeze, or given this is BR, 1963?

[grovenor-2685]

Or was the whole question TIC?

Well, it was mostly, but I have occasionally wondered how you calculate what the gap should really be - presumably based on ambient temperature at time of laying and length of rail to the next gap.

Yes, exactly so, and the platelayers manual would have a table to allow quick look up. I'm a bit surprised there isn't one of those in the GW P.Way notes, must have been another document.

And the spacers the gang were using don't seem to be removed - around 11:55 you see one still in place as a fishplate is bolted up, and a few seconds later the platelayer is knocking it sideways but still wedged in the gap. I suppose it falls out next time the temperature drops enough - 1947 Big Freeze, or given this is BR, 1963?

You don't see it removed in the film but it would have been, otherwise there would be a risk of buckles in the next warm spell, the gaps have to be gaps! Also the gang would be needing them again, those gauges were tools not consumables.
Regards
Keith

[Barry Davis]

But some railways did - see around 4:15 here. And if I want to get it "all right" when it comes to putting my jig-built panels down, who does scale versions of the expansion pieces shown at around 10:25?[/quote]

Hi David,

I do, but for practical purposes, and not for show. I have two small strips of brass shim, the summer one is approx. .2mm thick and the winter one is approx. .5mm thick, because the temperature in my train shed can vary from around 14 degrees in winter to plus 25 degrees in summer. When I lay any new track from May to August (NZ winter) I will set any expansion gaps at .5mm and from September to April (NZ summer) I reduce the expansion gap to .2mm. If I find the in the summer the expansion gap has closed up, it is a simple job to open it up with a fine razor saw. From experience I have found that if I fail to put in sufficient expansion gaps, my track can buckle in summer.

Regards
Barry

[Alan Turner]

And no we don't use a jig to build 12" to Foot track either.

But some railways did - see around 4:15 here. And if I want to get it "all right" when it comes to putting my jig-built panels down, who does scale versions of the expansion pieces shown at around 10:25?

Well if you want to "get it all right" no doubt you will be undertaking regular maintenance as per: https://www.youtube.com/watch?v=S5O5S-faOds

regards

Alan

[Will L]

Well if you want to "get it all right" no doubt you will be undertaking regular maintenance as per: https://www.youtube.com/watch?v=S5O5S-faOds

Yes I too had happy time looking at the various Youtub links that appeared when I finished watching dal-t's original link. I think that this one shows that building your point work on your Templot drawing is distinctly prototypical. (Beware another 20 minuets well spent warning)

[dal-t]

I have two small strips of brass shim, the summer one is approx. .2mm thick and the winter one is approx. .5mm thick

That's the sort of detail that is really useful, thanks Barry. In the past I've 'guesstimated' by eye but there always seem to be a couple of difficult spots that insist on jamming solid one minute then becoming a massive gap the next. I'll try those sort of thicknesses, particularly if building in my hot-house attic for transfer to my ice-cavern basement (except in the winter when the heating has failed, when it's the other way around!)

Well if you want to "get it all right" no doubt you will be undertaking regular maintenance as per: https://www.youtube.com/watch?v=S5O5S-faOds

Of course - must order in some of those metal key packing pieces, in case the next batch of C&L chairs come with metal keys

But to get back more on topic, I do wonder if there would not be some value in a P4 version of PH Designs sleeper spacing jig, as a helping hand for those of us who choose not to lay directly on Templot prints (personally, I've too many other calls on my time to persevere with software that has to be reinstalled every time you want to run it)?

[David Thorpe]

(personally, I've too many other calls on my time to persevere with software that has to be reinstalled every time you want to run it)?

I don't know which software you're referring to because that certainly does not apply to Templot, at least not on Windows.

DT

[Paul Willis]

(personally, I've too many other calls on my time to persevere with software that has to be reinstalled every time you want to run it)?

I don't know which software you're referring to because that certainly does not apply to Templot, at least not on Windows.

DT

In fairness to David, if you are only an occasional user of Templot, that can seem to be the impression.

Precisely because Martin cares so much about the product, there are innumerable little releases that he makes with tweaks here, and new features there. And because Templot is nicely packaged, each upgrade does require a new download and an install. Yes, it's quick and easy. More than you can say for some software. I have had Filehippo bleating at me for weeks about upgrading Adobe Air, but each time I try and do it, there is an need to do some sort of arcane uninstall of the old version before the new one will even try and load. You don't have these problems with Templot.

However, having not used the program for a few months, I'd bet that if I came to fire it up now, there's going to be a message about an upgrade needed.

Not a problem, not a bug, but a consequence of a continuous programme of rolling upgrades to the program.

So I would roll with it, and appreciate that it means software that is up to date and as bug-free as possible.

Cheers
Flymo

[Martin Wynne]

The last Templot update was 5 months ago, 2nd December 2014. It has been downloaded 3,047 times. http://templot.com

I'm hoping to have another one ready in the next week or two. Updating takes only a few seconds on broadband -- reading the notes about the new features takes longer.

Templot is free for anyone to use if they like it. Or not if they don't.

Martin.

[dal-t]

(personally, I've too many other calls on my time to persevere with software that has to be reinstalled every time you want to run it)?

I don't know which software you're referring to because that certainly does not apply to Templot, at least not on Windows.

DT

Ah, there's the rub - it does if you're running Yosemite (Mavericks was fine). Yes, it's only a couple of minutes each time, but partly its the yuck of always having to go through the pseudo-Micro$oft install process. And yes, it is every time, because the actual 'app' just doesn't stick, only the downloader (and that only works if you've fired up X11 first). So it's still pen and ink for me (although I can get RailModeller to run, now I've upgraded to 4.1.10, so at least I can work out how to cover the garden with Peco 'O' gauge). Maybe when Templot becomes compatible again I'll give it another try.

[Martin Wynne]

personally, I've too many other calls on my time to persevere with software that has to be reinstalled every time you want to run it

If you haven't got the time for the few seconds it takes to install Templot, you certainly haven't got time to actually use it, or the time to build some track on the printed templates.

For running on a Mac, try Codeweavers Crossover, or Winebottler (free). Lots of users run Templot that way, and none have reported needing to install Templot every time.

https://www.codeweavers.com

http://winebottler.kronenberg.org

Martin.