Track geometry - turn outs, 12 degrees etc

[Mathemagic]

I'm in the throws of starting a new project and am experimenting with different options at the moment. I've learned a lot already by reading through many forums but haven't quite found the answer to a question I currently have:

 

I bought a couple of the Peco starter sets so that I could have two ovals running quickly for my 4 year old whilst I plan things. However, I've found that my (approx) 40 years old class 47s for example don't like running over the ST-241 or ST-240 type of turnouts. I've therefore been looking into the streamlined sort such as SL-92 but can't get them to "work" when designing a track on SCARM. In my simplistic mind, I could branch off the main line coming ito a station using a ST-241 and a ST-225 curve to open up two tracks for, say, a station. That's what I used to do the last time I created tracks when I was much younger! However, with the streamline turnouts being 12 degrees, it doesn't look like there are any corresponding curves to "cancel out" the 12 degree turn. Am I missing something?

 

I'm sorry for such a newbie question and for it probably being a very basic one, but any advice on what people do instead would be greatly appreciated.

[DCB]

The easiest way to get the curve back to parallel is with  a short section of flexi track.  I don't know of any compatible set track curves so on occasion I have cheated and cut a piece from a large radius set track curve to suit.

 

I think the largest Hornby curve is 33" radius for the Y point and the 4th radius is about 22".  Larger radii are available, i see them in US magazines.   Sometimes I cut the webs between set track sleepers and ease the set track out to a larger radius, sometimes I use set track rails with flexi sleepers threaded on. 

 

The advantage of set track is the curve radius is generally uniform as both rails and track base are curved at the factory, flexi track has a tendency to want to straighten out and generally kinks at the rail ends unless laid very carefully, for this reason I try to use set track curves for any sharp 2ft radius or less curves, it is much more expensive than but the improved running is well worth it. Likewise set track straights are straight, and flexi is an absolute sod to get straight.  On my small layout I used set track straights to get that arrow straight steam era mainline look. Flexi is fine for the modern image dogs hind leg look.

 

Streamline points have the advantage of closer track spacing suited to 2ft radius and above curves, they take up less space laterally allowing 30% more sidings width wise in fiddle yards etc  yet are only slightly longer, and the Y is substantially shorter, than Set Track points.   Personally I would avoid set track points as they are barely 2nd radius, some older Hornby ones are 1st radius through the blades.

 

The Hornby class 47 is horrible. It picks up from one side of each bogie and can't get across double isolators between controllers. There is no easy fix.  Mine has 15mm tender drive wheels which is a big improvement.

Edited May 2, 2017 by DavidCBroad

[ejstubbs]

Setrack works to a basic turnout angle of 22.5°.  The curves are based on the same angular 'unit'.  Streamline uses 12°.  So, as you have found out, the two are not easily compatible 'out of the box'.  The closest match in the setrack range is the ST-238 special curve, which is actually designed to go with the setrack Y point.  The angle of this curve is 11.25° so it's closer, but still not right for streamline points.

 

If you have bought the Peco starter set then the radius of the curves and double curves in that set (ST-225 and ST-226) are the same as the nominal radius of the curves in the setrack turnouts.  So if your class 47s will go round the plain curves then that would tend to rule out the radius of the setrack turnouts is being the cause of the problem.  Much more likely is that the locos are losing power as they pass over the setrack points' plastic frogs ('insulfrog' in Peco parlance).

 

You might be able to cure this by investing some time in fettling the locos.  I'm not familiar with the class 47 model (I like steam engines!) so I can't offer any specific advice about the locos that are giving you trouble.  However, the basic principle which applies to all locos is to make sure that all the wheels and pickup wipers are clean: free of grease and encrusted dirt.  The running surfaces of the wheels need to be clean to ensure good current collection from the track.  The interface between the inside surfaces of the wheels and the pickup wipers also needs to be clean, so that the current can get from the wheels to the motor.  I use Isopropyl Alcohol (aka IPA, available from Maplin amongst other places) on a cotton bud to clean wheels, and the same stuff on a lint-free cloth (an offcut from an old shirt which has been retired from active service is good) to clean pickup wipers and the inside surfaces of wheels.  If there are any obvious lumps of crud that can't just be wiped off with IPA then a cocktail stick will often shift them.  Make sure to clean all the wheels - even those on your wagons and coaches - so that they don't spread encrusted gunk on to the rails.

 

You can get special soft metal brushes that carry current to the wheels and clean them as they rotate without abrading the wheel eg this one, or (better IMO) this one.  Bear in mind that these will not clean non-powered wheels, so those still need a manual clean from time to time.  The brushes also aren't great at cleaning encrusted dirt off the pickup wiper surface on the wheel backs.  I use very high number wet and dry for this job - at least 800 grade - if it's needed.

 

If you still want to try streamline turnouts then there are a few of things to bear in mind at the outset.  Firstly, to match up with the rails in your setrack curves and straights you will need the code 100 series streamline (the 'code' actually represents the height of the rail in thousandths of an inch).  Secondly, the code 100 streamline points come in two types: insulfrog and electrofrog.  Insulfrog streamline points have the same drawback as the setrack points in terms of current collection, ie a lump of plastic for the frog.  So these aren't guaranteed to be a magic wand solution to your running problems.  The electrofrog type - identifiable by an "E" in the part number eg SL-E91 & SL-E92 - are the same geometry as the insulfrog ones but have a metal frog which conducts power and could help solve your running problems.  However, the electrofrog ones do have some complication in terms of layout wiring; it's not quantum-physics-complicated but you need to be aware of how to deal with it.  I would strongly suggest having a look at Brian Lambert's excellent tutorials about layout wiring on his web site.  You don't need to understand all of it - it's well laid out so you can easily pick and choose the information you need.  Or you could even buy his book.

 

In terms of the track geometries, you need to be aware that not only do streamline turnouts not have the same nominal angle as the setrack ones, but they are not the same length either.  That means that they don't match up with the setrack straights 'out of the box'.  The solution to both issues is to cut track to the right lengths.  If you're going down the route of using flexible track then you would need to do this anyway.  If you prefer to use setrack then you will need to do some 'surgery': cutting straights to the right length, and curves to the correct angle.  The  best tool for this IMO is a Xuron track cutter, plus a scalpel or stanley knife to trim to sleepers.  You will also need a good way to measure curves so that you cut them to the correct angle; I use a template drawn on a bit of MDF using a ruler and protractor with the 12° angle marked, with tick marks at the different setrack radii.  (You will probably find that you need to trim the sleeper ends on the bits of setrack in order for them to fit on the diverging routes from the points as well.)

 

One good reason to use modified setrack curves with streamline points is that it's not straightforward to curve flexi track down the to small radii that setrack uses.  If you need "train set" curves in order to fit your layout in to the space you have available then this can be a good way to do it.

 

One further word of warning: the rail joiners that are fitted to setrack have a rolled 'lip' at the end.  This is designed to make them more robust if people have to assemble and disassemble there "toy train" every time they want to use it.  These will not fit streamline points, which don't have the massive gap in the sleepers under the rail ends that setrack does.  You can either snip off the lip, or you can remove the setrack rail joiner altogether (if it will come off - some of them seem to be welded on!) and use normal Peco rail joiners.  If you plan to use electrofrog points to help with current pickup then you will likely need to remove some of the setrack rail joiners in order to fit the insulated rail joiners you need with this type of point (see the Brian Lambert web page I referenced earlier).

 

You can avoid having to cut setrack curves if you always use streamline points in pairs.  For example, in the instance you cite with a passing loop at a station, you could make the loop using a crossover at each end.  That way the two 12° points would match up.  (It's actually more prototypical as well.)  The lengths of the straights would not match, though.  You also need to be aware that the distance between parallel tracks is different with streamline points (52mm vs 67mm for setrack).  This isn't an issue if you only have straight parallel tracks, but it does complicate things if you want double track curves.  I find a good track planning tool is invaluable in sorting out these kind of issues before you get to the point of cutting track.  I use AnyRail, which I find much easier to use than SCARM.  I've bought the full version - IMO the cost is likely recouped many times over in terms of avoidance of wastage of time and materials when it comes to actually building the layout for real.

 

Combining setrack and streamline in one layout is not that difficult provided you make sure you know what you are doing before you start - set about it without a bit of planning beforehand and it could all turn rather nasty.  I use streamline electrofrog points with modified setrack for my layout and the combination works fine.  As always with track laying, a bit of care and attention when the track first goes down - making sure that it's lying flat and there are no unexpected kinks at the rail joins - will pay dividends when it comes to running trains.  It's not as out-of-the-box easy as setrack, but it looks and works better, and is a good halfway house to all-streamline if flexi track isn't suitable (small radius curves) or just seems like too much work (that's me, that is).

Edited May 2, 2017 by ejstubbs

[34theletterbetweenB&D]

I believe it comes down to the space available and your own ambitions. If you have sufficient space to use curve radii larger than set track provides and would like to do that thing; then leave the set track as the 'get something running' phase to entertain your four year old, and start from a clean sheet with a flexi track system.

 

It is actually more work to integrate flexitrack pieces into a set track layout, than to do the same job all flexitrack; and if you can achieve the integration succesfully then you have the skills to go all flexitrack.

[Chimer]

By "don't like", do you mean your 47s stall or derail?  If it's stalling, read all above - but if it's derailing, it's possible the 40 year-old wheelsets are too coarse - I know code 100 is supposed to be universal, but I have one (now retired) old Jinty which routinely derailed on my Streamline Code 100 points.  If this is the problem, changing from Setrack to Streamline won't make any difference.

 

In passing, I too use Streamline points with Setrack curves and didn't have the problems using the fishplates fitted to the curves that EJS warns about - and having just checked, I can't see it produced any distortions if I did only achieve this using brute force ......

 

Cheers

 

Chris

[ejstubbs]

It is actually more work to integrate flexitrack pieces into a set track layout

 

Agree: I can't see any point at all in trying to do that!

Edited May 2, 2017 by ejstubbs

[ejstubbs]

I too use Streamline points with Setrack curves and didn't have the problems using the fishplates fitted to the curves that EJS warns about - and having just checked, I can't see it produced any distortions if I did only achieve this using brute force ......

 

I have a feeling that Peco are not (or have not been in the past) 100% consistent in how they assemble their setrack items - not all of them may have the 'roll' on the end of the fishplate.  However, the photo below shows a newly-purchased setrack curve (on the right) offered up to a newly-purchased streamline diamond crossing (on the left):

 

 

You can see the rolled-over bit at the end of the setrack rail joiner (and you can just about see the 'tack weld' or whatever it is that holds the joiner on to the rail, through the sleeper gap in the base of the setrack curve).  You can also see the gap for a rail joiner under the rail on the streamline component (upper left of the photo), and hopefully it's possible to discern that the 'roll' on the setrack fishplate is just a wee bit too large for that gap (roughly lower centre).

 

As I say, it's fairly straightforward to fix the problem so long as the setrack fishplate comes off without too much of a struggle.  Carefully snipping the 'roll' off with a decent pair of wire cutters, rather than hauling bodily on the fishplate, might carry less risk of distorting the setrack component.  In fact I'll probably try that next time 

Edited May 2, 2017 by ejstubbs

[Mathemagic]

Many thanks to all of the replies.

 

I didn't make it clear in my original post but my class 47s both derail but I've been experimenting this evening. 

 

I now have one loco that seems to be able to cope fine and one that derails at the first left turnout regardless of whether the motor end enters it first or last.

 

I think my next course of action is to open up the one that derails all of the time and see if there is something (wiring or something) that might be fouling the bogie when turning. All of the wheels are clean - but I had a coach that would always derail and I couldn't work out why until I noticed that the wheels weren't smooth - the imperfections were causing the wheels to ride up at the points - a new set of wheels and it is perfect at speed.

 

I may also experiment by adding a little more weight to the engine.

 

I did want to avoid flexi track if I could because when I was younger we had some and I never liked using it at all. 

 

On the topic of the 12 degrees turnouts - I like the idea of using them for the fiddle yard - it hadn't occurred to me to save space there. Thank you for that suggestion.

 

At some point (once I've sorted the garden out to fit a 16' by 10' shed in!), I'll actually have to start designing it! I'll put that on another thread as I'm too logical to think "curvy". Maybe I could open it up for people to suggest layouts! 

[ejstubbs]

I didn't make it clear in my original post but my class 47s both derail but I've been experimenting this evening. 

 

See Chimer's post earlier: if your investigations of the 47's internals are fruitless you may need to consider putting more modern wheels on it.

Edited May 2, 2017 by ejstubbs

[knitpick]

Re Chimer's comment - you don't say whether the class 47 is Hornby or Lima.  But the older Hornby locos do have very coarse wheels - just look at the wiidth of the wheel treads and compare with modern items (e.g. a £10 Oxford wagon).  As a result, they tend to derail on current standard pointwork.  In contrast, Lima equipment has very deep flanges but is normally OK on Settrack and Peco code 100 flexitrack; it runs on the sleepers of code 70 track.

 

Unfortunately you can't just ease the Hornby wheels further apart as the gears are attached to the wheels on one side of the bogie.

[Mathemagic]

After the advice above pointing at the wheels and many more trials I found the solution - the wheels were too tight on the block at the engine end - just easing the driving wheels apart a fraction of a mm has solved it (I've checked there isn't enough play for the cogs to miss - a problem I was having on another loco!_) - I can now run the class 47 at full speed through a left followed immediately by a right turnout without any issues. I'm very pleased because I can get back to using set track rather than more streamlined turnouts in my design.

 

Thanks to all.

Edited May 4, 2017 by Mathemagic