Trackwork options for newbie

[John McAleely]

for future reference it is more suited to the 'Track and Turnouts' thread or here under 'Starting in P4'. Is there a way of linking between the two?

There is, and I regularly make such amendments, as do others in the moderating team. I often prefer to let the thread run it's course before acting for posterity.

Regular users don't have an easy way to do this unfortunately.

[Will L]

David (Thorpe), Terry,

Thanks for the info re Masokits stretcher bars - I'll look into these, too.

Its best to differentiate between a functional Point Operating Units, which you will need and are normally hidden under the track and attempts at scale stretcher bars which are usually not doing anything functional, and for the newbie can be left off until your feel your skills are up to it.

[David Thorpe]

My Masokits stretcher bars are functional, being operated directly by Tortoise motors under the baseboard.

DT

[Will L]

My Masokits stretcher bars are functional, being operated directly by Tortoise motors under the baseboard.

DT

Yes David I know you can do it, you can also drive the point via scale point rodding from the signal box if you try hard, but is this really the method you think newcomers should try first?

[David Thorpe]

I really don't know what you mean, Will. I decided on the Masokits stretchers not because of their prototypical accuracy, although they do look good, but because I thought they'd be easy to make and to fit and that they'd work - yes in all instances. My system of direct connection between the stretcher and the Tortoise or Cobalt, while probably not particularly attractive to prototype purists, is as easy, if not easier, than any other point changing system I've yet tried, although I should perhaps confess that in the past I have always found fitting of point motors to be a tedious and sometimes troublesome task.

DT

[Ade]

for future reference it is more suited to the 'Track and Turnouts' thread

Probably, yes. I just assumed that the most basic of questions should be asked in the "Starting in P4" forum.

My Masokits stretcher bars are functional, being operated directly by Tortoise motors under the baseboard.

DT

David,
Do you have any photos, by chance, that you can link to please? Thanks!

OK gents, getting back on track (ha ha)... I've ordered Exactoscale points kits and some plain track and am now waiting for Royal Mail and Swiss Post to do their thing. In the meantime, I've decided that my immediate priority is to build a very simple "plank" to try out my track building skills which, if all goes well, will give me a handy piece of track for testing my re-wheeling skills. Whilst this is in progress I will be thinking ahead to a "proper" P4 project...

[JFS]

... you can also drive the point via scale point rodding from the signal box if you try hard....

You can, and I do - it is great fun - you don't have to be mad to try it but in my case it certainly helped...

But, equally I never got on with under-baseboard drives - certainly not when I was a newbie 40 years ago (mind you I was only about 15 at the time!) - and we had dreadful trouble with the Studiolith TOUs. (unpredictable stroke, blades lifting, crud finding its way into the holes, blades sticking on non-existant slide chairs....)

Personally, I think that both the Ambis and the Masokits stretchers are easily strong enough to be used functionally, and there are many ways of rigging up a drive to them via a convenient bell crank - also available from Masokits.

If you can afford it Ade, best thing might be to build a "plank" first and try out a few different methods before embarking on the Magnum Opus. As you can see from the comment here, there are lots of ways of doing these things and all of us have different criteria by which we decide what works best for us.

Best wishes,

[David Thorpe]

David,
Do you have any photos, by chance, that you can link to please? Thanks!

I'm afraid I haven't been able to take any photos of my own as the things are so tiny, but there are some quite good ones here: http://line2nowhere.blogspot.co.uk/2008 ... e-bar.html

They're £4 for a fret of 12 - see Page 8 of the Masokits catalogue hosted on the S4 Soc website. (http://traders.scalefour.org/masokits/).

DT

[grovenor-2685]

Personally, I think that both the Ambis and the Masokits stretchers are easily strong enough to be used functionally, and there are many ways of rigging up a drive to them via a convenient bell crank - also available from Masokits.

Cranks also available from Ambis as well as an underboard drive unit (PALM) to go with it. I have built one on a demo board but concluded that replacing the ones on my layout (mostly the Studiolith ones!) was not a goer for me.
Demo unit here above board, and here the underboard PALM.
The vids were made well after it had served its purpose so the servo that originally drove it had been removed and the adjustment for the right hand blade is out.
Regards
Keith

[Ade]

If you can afford it Ade, best thing might be to build a "plank" first and try out a few different methods before embarking on the Magnum Opus. As you can see from the comment here, there are lots of ways of doing these things and all of us have different criteria by which we decide what works best for us.

Best wishes,

That's what I'm doing, Howard. As you say, it will give me a change to try out a few things and see which I prefer.

[Ade]

David,
Do you have any photos, by chance, that you can link to please? Thanks!

I'm afraid I haven't been able to take any photos of my own as the things are so tiny, but there are some quite good ones here: http://line2nowhere.blogspot.co.uk/2008 ... e-bar.html

They're £4 for a fret of 12 - see Page 8 of the Masokits catalogue hosted on the S4 Soc website. (http://traders.scalefour.org/masokits/).

DT

Thanks, David. That's fine, the photos on the site you linked to give me a good idea. Thanks again.

[Ade]

Cranks also available from Ambis as well as an underboard drive unit (PALM) to go with it. I have built one on a demo board but concluded that replacing the ones on my layout (mostly the Studiolith ones!) was not a goer for me.
Regards
Keith

Very useful, Keith, thanks. The underboard PALM linkage version is very cool. Looks great. In case anyone hasn't seen this, here's a link to the Ambis explanatory document which gives some useful information on prototype practice for point rodding: http://ambisengineering.co.uk/pointroddingwiresystem_pt1.pdf. It's not quite for the era I am modelling though, so I'll need to find something that looks more modern.

[JFS]

Cranks also available from Ambis as well as an underboard drive unit (PALM) to go with it. I have built one on a demo board but concluded that replacing the ones on my layout (mostly the Studiolith ones!) was not a goer for me.

Indeed so! And can't say I blame you for not wanting to retrofit!! If a thing works...

Just to mention one issue for the unwary / inexperienced. The nature of the Ambis stretcher end is such that the drive wire is "live" to one rail, whereas the Masokits one is insulated.

Ambis stretchers .jpg

This can be an issue if (say) two ends of a crossover are linked mechanically under the baseboard (or if your rodding is functional!!). not difficult to solve provided you think ahead. The advantage of the Ambis approach over the Masokits one is that the PCB requires only a single set of electrical gaps and so is physically much more robust.

EDIT:- Just also to mention that the Ambis components above are the Ambis "MkIII" whereas the current and improved version is MkIV (or as the Romans would write it MkIIII).


Best wishes,

[Mark Tatlow]

Mark,
Thanks for the advice! I've definitely come to the conclusion that I'll start with Exactoscale kits and I'll order those gauges whilst I'm at it. However, I'm not sure I quite follow your remark "the switch blades tend to slightly flex outwards in assembly and subsequent testing (as they are not restrained)". Can you explain, please? Perhaps this is something that will become blindingly obvious when I have a kit in front of me.

Hi Ade

An Exactoscale turnout kit comes with pre-assembled switch rails; where the switch rail (the bit that moves) is prefitted to the stockrail. This sets them up at the right location and they look like this:

161.JPG

You first place one on the base piece by reference to some location pips like thus and secure with some solvent:

370.JPG

The you put the second one in place in the same manner but use the Exactoscale gauges to make sure it is space out to the right degree like thus:

376.JPG

The significance is that the switch blade is only secured at one end - the heel, in this case to the right hand side of the photographs. This means it can flex a little as it is not otherwise restrained and it will to a small degree. Compensate for this by using the slight larger gauges - either the +0.1mm as I am in the photo or the +0.2mm as I note Andrew Jukes does (and he is part of the team that came up with these kits, so ought to know!!!

With regard to the use of stretcher bars, I go for a more crude and robust approach. In this regard I do use a PCB stretcher bar secured to the ends of the switch-blades but I lower it down approximately 3-4mm, so that it is hidden below the sleepers and can be covered over.

I achieve this by using some brass strip that sits tight to the underside of the stockrail and is secured to the switchrail, with a small wire to aid the strength of the joint. I find that the locational certainty that this gives me, because of the bar being tight below the stockrail, is worth having and makes for more reliable running.

This is not to everyone's taste and just proves that there is more than one way of skinning the cat! The theory that people offer for not liking it is that there is a stress at the point of contact between the brass strip to the switchrail because it can not flex. This is why I use the brass wire to strengthen the joint and I reckon that there is more than enough strength to see me in my grave! Indeed, I would say these are a lot stronger than the other options!

This is what it looks like:

228compress.JPG

233compress.JPG

DSC_0409.JPG

[Ade]

Mark,

Many thanks indeed for the detailed explanation and photos - really useful! Thanks.

[Terry Bendall]

This can be an issue if (say) two ends of a crossover are linked mechanically under the baseboard (or if your rodding is functional!!). not difficult to solve provided you think ahead.

Whilst I don't use functional rodding, I have worked both ends of a crossover using the same point motor and linkage between the two cranks made using 3mm square brass tube. The ends are insulated using a piece of acrylic between two sections of the tube. This is filed down to fit inside the tube and fixed with 10BS nuts and bolts.

Terry Bendall

[andrew jukes]

Mark said:

This is not to everyone's taste and just proves that there is more than one way of skinning the cat! The theory that people offer for not liking it is that there is a stress at the point of contact between the brass strip to the switchrail because it can not flex. This is why I use the brass wire to strengthen the joint and I reckon that there is more than enough strength to see me in my grave! Indeed, I would say these are a lot stronger than the other options!

The trick here is to find a method that allows the whole length of the switch planing to contact the stock rail for each road as it's set. Strong but rigid joints between a functional stretcher and the switch rails make this more difficult as the geometry doesn't really work. Hence the widely recommended pivoted joints.

The geometrical problems of getting good contact between switch and stock rails is made worse if two stretchers (which may be intended to be primarily cosmetic) form a fairly rigid square assembly.

A consequence of not getting full contact between the switch rail planing and the stock rail is (assuming a correctly shaped switch rail) that the track is likely to be under gauge at the end of the planing.

I have long felt that the ideal is to separate functional and cosmetic aspects, using pivoted joints to a concealed functional drive arrangement and cosmetic stretchers that more or less float in the web of the switch rails. Unfortunately the latter does not exist as a manufactured product!

Andrew Jukes

[Jol Wilkinson]

I have long felt that the ideal is to separate functional and cosmetic aspects, using pivoted joints to a concealed functional drive arrangement and cosmetic stretchers that more or less float in the web of the switch rails. Unfortunately the latter does not exist as a manufactured product!

Andrew Jukes

Why not use the Ambis Mk IV stretcher (the simple Ambis variety) and solder to one switch rail only, leaving the other end free to move. I have found that the stretcher is robust enough to stay in vertical and horizontal alignment while attached at one end only.

Jol

[JFS]

The trick here is to find a method that allows the whole length of the switch planing to contact the stock rail for each road as it's set. Strong but rigid joints between a functional stretcher and the switch rails make this more difficult as the geometry doesn't really work. Hence the widely recommended pivoted joints.

The geometrical problems of getting good contact between switch and stock rails is made worse if two stretchers (which may be intended to be primarily cosmetic) form a fairly rigid square assembly.

A consequence of not getting full contact between the switch rail planing and the stock rail is (assuming a correctly shaped switch rail) that the track is likely to be under gauge at the end of the planing.

I have long felt that the ideal is to separate functional and cosmetic aspects, using pivoted joints to a concealed functional drive arrangement and cosmetic stretchers that more or less float in the web of the switch rails. Unfortunately the latter does not exist as a manufactured product!

Andrew Jukes

Andrew,

I am not sure how many functional tiebars you have had fail on you, but I am afraid I must to some extent disagree here. If I paraphrase your statement above (I hope not unfairly!) you are saying that using stretchers with ends ridgidly attached to the switches must result in under gauge switches. The missing ingredient in your argument is that the stretcher bar itself takes up the flex (as it does on the prototype). Of course, its design must be such as to allow that - hence I use GRE and not PCB for my stretchers, and also why Mike Norris passes the securing wires through the PCB on his design. So a bit of thought needed, but it can be done, it can be made very robust and it does not require a tonne of underbaseboard gubbins which - in my experience - can cause a set of issues all its own. Worse, (and to agree with you to this extent) as soon as you add "cosmetic" bits on top of functional bits, you have introduced an opportunity for bits to fight against each other and doubled the number of bits to go wrong / fall off.

Here are a pair of pics (on a tandem turnout) showing the degree of flexing and it is not inconsiderable.

Flex -1.jpg

Flex -2.jpg

I trust you will concede that the switches are indeed in contact with the stock rail throughout the planing length.

I am sure you will be at Scaleforum, and I will be there with the baseboard on which the above picture was taken - I hope you (or anyone else) will drop by to have a look - I won't be seeking to change your mind - not least because your layout is very different to mine - but I will be hoping to at least to show you that it can be done, that it works well and is just about the simplest solution!

So whilst I fully agree that the method I use will not appropriate for every sitiation, please don't tell me it can't work, because it can and it does!

Best wishes,

[Martin Wynne]

we had dreadful trouble with the Studiolith TOUs. (unpredictable stroke, blades lifting,

An essential function of a stretcher bar, in addition to holding the switch blades the correct distance apart, is to hold them down on the slide chairs and prevent the tips from kicking up as wheels run over the heel end. The stretcher bar does that by running closely under the stock rails, or in old round-bar designs by running through holes in the stock rails.

Unfortunately Studiolith failed to replicate this essential function in their TOU design, leading to much grief at the time.

Martin.

[grovenor-2685]

Unfortunately Studiolith failed to replicate this essential function in their TOU design,

Well it was certainly the intent of the design and works if correctly installed, I still have many of these in operation and the dropper includes a horizontal section that sits under the stockrail to hold the blade down.
Keith

[Martin Wynne]

Thanks Keith. I stand corrected, and I've found the original Studiolith diagram to prove it:

studiolith_tou.png

Which leaves me a bit puzzled. Because I can well remember many layouts where the holes for the dropper pins were inside the 4-foot and directly below the blade points. Howard's comment about blades lifting would seem to confirm my recollection of the problems with them.

regards,

Martin.

[Ade]

Wow! I think this thread is becoming a repository of a lot of very useful info. Thanks to all contributors!

Pulling the thread back a little towards its original purpose, and whilst waiting for my Exactoscale supplies to wing their way across Europe, I've been musing about options for modelling modern FB rail and concrete sleepers. What are the options? I've seen that Colin Craig makes up kits to order, but wondered whether there are any other options that folks recommend. Thanks!

[JFS]

Thanks Keith. I stand corrected, and I've found the original Studiolith diagram to prove it:

Which leaves me a bit puzzled. Because I can well remember many layouts where the holes for the dropper pins were inside the 4-foot and directly below the blade points. Howard's comment about blades lifting would seem to confirm my recollection of the problems with them.

On the first layout, (which existed until very recently) my mate and I got these things to work tolerably well, but they tended to be unreliable and the main issue was that if anything got in the way of the easy movement of the blades, the stainless steel tubes would bend, tending to tip the blade. And the thing which usually got in the way was the drag of the blades over the rivets which served for slide chairs. Another issue was that crud tended to find its way into the hole - mainly because we never got round to covering the holes with paper / ballast etc as the design envisaged. A lot of our issue with lifting blades stemmed from the fact that we found setting the thing up to be quite tricky - reaching over the baseboard to the already-laid track, then holding the dropper wires against the underside of the rails whilst soldering them to the switches. We also found that - for whatever reason, if the droppers were set up at right angles to the rail, the switch openings were excessive - the resulting angularity reducing the control over the blade height.

Bearing in mind that at the time we were spotty teenagers unable to afford even half a toolkit, there was a fair bit of poor workmanship going on, and I am pretty sure that if we were doing it again we could make a much better fist of it - but why bother? there are far better looking and far better functioning systems available

But teenage hamfistedness aside, I do consider that entirely sub-baseboard solutions like this have a fundamental flaw - which I hope I illustrate below

Switch drive.jpg

The natural tendecy when seeing a gap at the switch is to increase the throw - which of course just makes things worse..

And although from Ade's point of view Studiolith bits are historic curiosities only, this issue of driving "remotely" (In our case through no less than 3/4" of chipboard) remains a potential issue in the concept.

That layout also sported large holes in the fourfoot Martin - mainly because we did not realise they were needed until after we had laid the track - so "under the rails" involved a fair bit of unsoldering and compromise was the outcome! I can't of course, say that was the issue for all the other layouts - but I too remember a lot of such holes!

On my previous layout, I used an under-baseboard system which was developed from a concept which Stuart Hine published in the old Model Railways and very well engineered it was. My execution of it was rather more crude, but involved a larger excavation in the baseboard with a vertical piece of PCB serving as a the drive and serving to hold the vertical levels - it worked quite well - but it was a fag to set up and a pain to adjust. That layout does still survive, but I am not sure if the present owner is yet running trains on it - he will no doubt comment!

Good debate chaps - keep it up! Glad to see that Ade is still with us and hopefully feeling helped


Best wishes,

[martinm]

modelling modern FB rail and concrete sleepers

Well, it all depends what you mean by "modern"!
There is a very thorough expose on flat-bottomed track by Colin Ceraig at http://www.mmrs.org.uk/technical/track.html although it currently stops at new track of 2004.

Network Rail is using UIC60 rail (125 lb/yd) as its standard for high speed lines. Other lines seem to be still in the equivalent to UIC 54 rail (113 lbs/yd)

I have a note that I copied from somewhere re :
That therefore means that the choice we have in 4mm scale is:
• C&L - representing the E1/4 - manufactured 1944 – 1954 ( Sleepers - 'Dowmac' concrete (for bullhead rail) 4SL104A)
• Exactoscale - representing the F27 - manufactured 1969 - 2003 (Concrete sleeper FastTrack for FB rail E4FT 103A)
• Peco - representing the F40 - manufactured 1983 - 1999 (not much use for P4!)
and of course there are Colin Craig's parts.

So some ' modern' is catered for, but not all (I'm looking for LMS f/b in the 1930s)

Hope this helps,

martin