Peco scissors cross over

[robrailltd]

Hi as it states in the title i require one for space saving requirements. and as i'm building a temporary Layout DC only layout i want to know how i'm to wire it in, included if i need to use insulated fish plates etc. cheers for the help guys.

[96701]

Is My link useful?

[robrailltd]

I'm not sure. i think that deals with dcc. it says traditional toggle switches which again i have no clue regards. thank you anyways.

[Grovenor]

About the only useful bit in that link is that it does show the somewhat poor way that Peco have designed it, that at least can be worked around. The rest of the recommendations are poor.

Once you get to formations of this type in DC it is essential to consider it in relation to the rest of the layout around it and to the wiring scheme for the layout, failure to do that you get a poor result. With DCC its easier as you don't have to think of the sections.

For a scissors the first requirement is likely to be to allow parallel moves hence the two straight tracks would be in different sections, then trains crossing will involve section switching so it may be best to have the 4 approaches as 4 seperate sections, at which point you find that Peco have omitted an essential insulated joint (as well as providing several unnecessary ones, but those are easily shorted out).

It also matters whether your control scheme is using common return or not.

 

So if you can answer these questions then sensible advice can be provided.

1. Diagram of layout showing all other tracks and points around the scissors.

2. How many controllers in use?

3. How they are connected to the sections?

4. How will the points be operated, by hand, by Peco solenoids, by Tortoises etc?

5. Do you want provision for signalling?

6. What level of prototype fidelity are you looking for?

 

Regards

Keith

[sagaguy]

Hi as it states in the title i require one for space saving requirements. and as i'm building a temporary Layout DC only layout i want to know how i'm to wire it in, included if i need to use insulated fish plates etc. cheers for the help guys.

 

 

Have a look here near the bottom of the page.Although it shows what you are looking for,it`s also useful for wiring electrofrog diamond crossings.

 

www.brian-lambert.co.uk/Electrical-2.htm

 

Ray.

[hayfield]

Wireing a crossover is quite simple once you understand the basics.

 

the 2 stockrails polarity allways remains the same

the 2 V's polarity changes depending on which route is taken, and are allways opposite to each other

 

This link may help http://www.finescale.org.uk/images/stories/pdfs/S_Slip.pdf . Its for a single slip but the principle is the same

[Grovenor]

Hi as it states in the title i require one for space saving requirements. and as i'm building a temporary Layout DC only layout i want to know how i'm to wire it in, included if i need to use insulated fish plates etc. cheers for the help guys.

 

Its not important, why you want to use it, the wiring diagram depends on the answers to the 6 questions I asked above.

Regards

Keith

[GreenDiesel001]

Hi.

 

Are you talking about 4 points, 2 x r.h and 2 x l.h. and a diamond crossing joining them?

 

Cheers,

 

Jeff

[robrailltd]

right guys. I'm going for dcc from the start. this is the layout. can you please show where i need to put isolating fish plates. you at the station junction the 3 way at the bottom is sidings. the two spurs will be a MGR loop.

 

 

Roughlee Central3 by gavindr7, on Flickr

[Brian]

Hi

As you're DCC and assuming all or some of the points are to be Electrofrog - Live frog points, then the easiest way is to fit an Insulated Rail Joiner (IRJ) to the ends of all electrofrog points Vee rail ends.

Standard turnout would have two IRJs, a 3 way point four IRJs, Double slip four etc

Then install new rail feeds to the rails after the IRJs from the appropriate DCC bus wire. Of course ideally all track sections should have their own dropper wires fed from the bus anyway..

[robrailltd]

Excellent Brian. I've added your website to my favourites for reference.

[robrailltd]

Two questions spring to mind.

 

1a) what is a polarity change over switch with regards to the crossovers and how would one go about installing or making one? B) would it be required also for a single slip?

 

2) can all 4 points in the crossover be controlled fro one switch would it be over loaded?

[Grovenor]

Your question 1a) suggests you still need to follow the links given in earlier answers and read up on 2-rail wiring. The polarity switch is used to connect crossings (frogs) to one or other of the rails depending on the setting of the points, sometimes the blades of the points are used to do this eg. Peco electrofrog points, sometimes it is done by a separate contact attached to the point motor or lever, this is usually the case with homemade points and is also required with point formations such as the scissors crossover where there are more frogs than points.

Now you have changed to DCC here is the wiring diagram for the Peco scissors.

 

 

In respect of your question 2, it is possible to operate all 4 points together but it is very undesirable, in the prototype it is normal for the interlocking to prevent both crossovers being reversed together, in the model reversing both prevents you from setting the polarity of the diamond correctly and therefore requires dead frogs or a separate switch that cannot be linked to the point operation. The crossovers should be operated one at a time as shown in the 3 diagrams below.

 

Regards

Keith

[Gwiwer]

You say you are building a "temporary DC-only layout". If that is the case the simplest way to manage such a crossover is to use insulfrog points and rely on point blade contact for power supply and isolation. There will be many experts here wringing their hands and shaking their heads at such a thought but the OP is not asking for chapter and verse on an exhibition-quality permanent layout as I understand the post.

 

I use exactly that set up on a large permanent layout at the fiddle-yard entry. The yard doubles as through roads and is effectively a series of up and down sidings or loops off hidden main running lines. As such I find it useful to be able to cross trains from up to down at either end (or vice versa) so that they can change direction in the yard.

 

Four insulfrog points are connected by live joiners to the four ends of a short diamond crossing to form the "scissors", are powered by Peco surface-mounted motors and are not fitted with any other form of isolation. The layout is a DC-only operation and the set-up works perfectly. It is basic, easy and cheap to build and wire and has been reliable in operation.

 

The only consideration - as this is DC - is that a full circuit must be set up. Running through on the straight is no problem. Setting up a crossing move I also need to set up the reverse move at the far end (even if the train isn't going to proceed that far) in order to avoid accidental movements of other trains or conflicting current flows unless the train is entering a dead-end siding. It's easy and takes just a few seconds to get used to and to do each time.

 

Starting from there for a temporary layout you can then learn and develop skills to create just about any set-up you wish. But from a learning point of view it can be a step to far to consider fully interlocked and electronically-controlled points and signalling until the basics have been grasped.

[Baby Deltic]

Now why can't Peco do one of those in OO?

[Gwiwer]

Now why can't Peco do one of those in OO?

 

It would save on joiners but you can easily make your own with four points and a short crossing.

[Joseph_Pestell]

Now why can't Peco do one of those in OO?

 

Shinohara do one that can be used with Peco (Code 100) OK. Their Code 83 takes a bit more work to match to Code 75.

[the penguin of doom]

Now why can't Peco do one of those in OO?

 

I don't know how well the N gauge one sells, but this may have a bearing on why a OO gauge one is not available.

 

I'd certainly make use of them in a proposed track plan in OO.

 

Cheers.

 

Sean.

[the penguin of doom]

 

 

Shinohara do one that can be used with Peco (Code 100) OK. Their Code 83 takes a bit more work to match to Code 75.

 

Is code 100 the more coarse profile? I can never remember.....

 

Cheers.

 

Sean.

[the penguin of doom]

Marcway list a OO scissors crossover in their list.

 

Not sure if they do one in N though.

 

It is quite expensive - for obvious reasons I guess - so might not be viable on a temporary layout.....

 

Cheers.

 

Sean.

[Gwiwer]

Code 100 is coarser profile. The rails are 100/1000" high. Code 83 rails are 83/1000" and code 75 are 75/1000"

 

I suspect apart from having relatively limited appeal that there might be issues in preventing a full double-track crossover unit in 00 from warping slightly in the pack over an extended shelf life. It would also be quite a large pack!

[Joseph_Pestell]

Code 100 is coarser profile. The rails are 100/1000" high. Code 83 rails are 83/1000" and code 75 are 75/1000"

 

I suspect apart from having relatively limited appeal that there might be issues in preventing a full double-track crossover unit in 00 from warping slightly in the pack over an extended shelf life. It would also be quite a large pack!

 

Not such limited appeal as all that. I can remember selling plenty of them at various shows.

[Gwiwer]

And as I mentioned I have that set-up myself to provide fully-flexible entry to / exit from the fiddle yard between the two main lines. But if I were asked to suggest what I would dearly wish for in RtP track it wouldn't be what I can already make up, it would be a diamond crossing with one track curved to permit true parallel tracks through junctions instead of requiring a curve at the point, a straight over the diamond then another curve. It's near-impossible to make that smooth and to also have the other track perfectly parallel.

[the penguin of doom]

Thanks for clarifying that for me Gwiwer.

 

I too have had that diamond crossing dilemma on our current club layout. I think I've disguised it quite well but a curved diamond would have made it a lot more pleasing to the eye.

 

Cheers.

 

Sean.

[Colin_McLeod]

It would save on joiners but you can easily make your own with four points and a short crossing.

That gives the same arrangement but increases the distance between the parallel tracks.