Cross over a Scissors Crossing

[rab]

I've searched previous topics on this subject, but can't see one that answers what I'm looking for.

 

Basically I have a dogbone roundy layout, and I would like to have a scissors crossing

(Peco SL 383F) where the two parallel sections run close to each other.

 

I've searched the internet for a wiring diagram, but can't find one which is appropriate.

 

I'm using DC not DCC with manual operation, no turnout motors.

 

I've tried Brian Lambert's excellent site, but the nearest I can find is a diagram for a crossover.

 

Will this give me what a need; if not can someone point me in the direction of a suitable wiring diagram.

 

 

Edited September 9, 2022 by rab

[Chimer]

Does it not come with a wiring diagram in the box?  I don't know, but I'd expect one as part of the deal .......

 

You will of course be creating two reverse loops which may introduce additional pain - good luck!

[melmerby]

42 minutes ago, rab said:

I'm using DC not DCC with manual operation, no turnout motors.

That makes a problem job a lot harder.

All the wiring tips I've found online typically use DCC & a frog juicer.☹️(or other way of reversing the feed)

 

Something has got to switch the frogs for the different routes, so you would need some switches or relays, (ideally linked to turnout motors.)

 

What sort of manual control are you using?

Edited September 9, 2022 by melmerby

[WIMorrison]

I think you will also need to put in a reversing loop of some description on one of the dog bone to counteract the polarity reversal that will happen, otherwise you will get a dead short under certain conditions.

[melmerby]

1 hour ago, WIMorrison said:

I think you will also need to put in a reversing loop of some description on one of the dog bone to counteract the polarity reversal that will happen, otherwise you will get a dead short under certain conditions.

I thing doing it manually is going to be virtually impossible as the number of switching combinations required is going to make operation difficult in the extreme.

You have to switch the frogs in synchronicity as well as catering for a reverse loop across the junctions, all done by hand.

 

 

 

[rab]

3 hours ago, melmerby said:

What sort of manual control are you using?

Hand of God :)

 

The scissors crossing will be right next to the operating area so easy to reach.

 

It's in a fiddle yard, so hand of God is ok!

[rab]

4 hours ago, Chimer said:

Does it not come with a wiring diagram in the box?  I don't know, but I'd expect one as part of the deal .......

 

You will of course be creating two reverse loops which may introduce additional pain - good luck!

I bought it second hand on ebay

[rab]

Just now, rab said:

I bought it second hand on ebay

I think I was being over ambitious, (par for the course with me),

but that was the idea.

 

I eventually want to connect it to the 'scenic' part of the layout.

Originally I was going to have two reversing loops, both feeding

into the fiddle yard, so that I could run a train off the scenic part,

from either direction, then send it back the opposite way.

 

For some reason I just like the look of a scissors crossing (sad person)

so thought I could use it to form/link the two reverse loops.

 

I think I'll go back to two separate reverse loops,

and put he scissors crossing back on ebay :)

[njee20]

You can snip some of the feeds underneath and it’ll work out of the box. I bought one so treated (without realising that was the case). It didn’t work well at slower speeds, as you have a large unpowered area, but it did work. 

I’ll try and dig it out and photograph the modifications. 

[DCB]

5 hours ago, melmerby said:

I thing doing it manually is going to be virtually impossible as the number of switching combinations required is going to make operation difficult in the extreme.

You have to switch the frogs in synchronicity as well as catering for a reverse loop across the junctions, all done by hand.

A microswitch operated by the one or more or the scissors points tie bar or a pair operated by a microswitch on each tie bar can give the inputs you need to change frog polarity if you have a Live frog Diamond in your Scissors.  I wouldn’t as the the issue of authority and which way trains are going across the diamond makes this a nightmare. My live frog diamonds have four pole relays changingthe frog polarities.  I had something similar on my loft layout and gave up trying to get my head round it.     Dead frog makes it a lot easier but even so you will need DPDT switches so you can switch the controller to the next section in the right direction.  Absolute minimum you need 1) left loop, 2) right loop 3) Up Scissors. 4) Down Scissors sections.  Anything but running round the outside means changing swtches constantly. and when the train, not just the loco has left the previous section as every set of metal rolling stock is a potential short circuit.     I guess you could automate it with irdot or magnets but life is finite.     Really it's so complicated it's going to be a PITA.  Mind you DCC with hours of drilling dropper holes and soldering droppers and programming  is potentially a bigger PITA.   Might be easier to take up fly fishing or use battery powered R/C...

Edited September 10, 2022 by DCB
Read Scissors as double slip...

[kevinlms]

49 minutes ago, DCB said:

Mind you DCC with hours of drilling dropper holes and soldering droppers and programming  is potentially a bigger PITA.   Might be easier to take up fly fishing or use battery powered R/C...

Perhaps you should take up a hobby other than model railways, as others seem to have none of the problems listed with DCC.

[adriank]

Try this wiring diagram. I used the Megapoints Servo Controller 4R with the relay option. It works well but I was advised that it's not as fast as a frog juicer. I use DCC.

 

adrian

[DCB]

2 hours ago, kevinlms said:

Perhaps you should take up a hobby other than model railways, as others seem to have none of the problems listed with DCC.

Other way round, DCC users enjoy the hobby of Electronics, my outside railway works very well on batteries, no stalling, no soldering droppers. I had three hours of soldering  last week realigning tracks damaged by the hot weather, sorting dry joints etc.  I am no good at soldering  I don't like soldering, except for live frogging points.  Anyway I have had almost exactly the problem the OP has and it's pretty much insoluable with 2 rail track power unless you feed sections through DPDT reversing switches.   My loft layout was approx 15ft X 9ft  and was going to be relay controlled, working semaphore signals, operated by magnets and reed switches but it became an electronics project not a model railway, something like £1K worth of electrical kit in 1996 and is effectively abandoned except as an incredibly awkward to access  test track with 4 storage loops taking 11 coach trains hidden behind the board for a never built through station.    A cautionary tale.

[Enterprisingwestern]

12 hours ago, Chimer said:

Does it not come with a wiring diagram in the box?  I don't know, but I'd expect one as part of the deal .......

 

You will of course be creating two reverse loops which may introduce additional pain - good luck!

 

I would have thought the wiring diagram will be available from the manufacturer, or, ask on here, somebody will have one.

 

Mike.

[WIMorrison]

4 hours ago, DCB said:

Mind you DCC with hours of drilling dropper holes and soldering droppers and programming  is potentially a bigger PITA

 

There speaks a man who is actually uninformed of DCC and the simplicity that it provides, who has gained his 'knowledge' from similarly uninformed people. 

[hayfield]

9 hours ago, rab said:

I think I was being over ambitious, (par for the course with me),

but that was the idea.

 

I eventually want to connect it to the 'scenic' part of the layout.

Originally I was going to have two reversing loops, both feeding

into the fiddle yard, so that I could run a train off the scenic part,

from either direction, then send it back the opposite way.

 

For some reason I just like the look of a scissors crossing (sad person)

so thought I could use it to form/link the two reverse loops.

 

I think I'll go back to two separate reverse loops,

and put he scissors crossing back on ebay :)

 

I think what you will need to do is to isolate the diamond crossing from the turnouts

 

The difficulty comes when you wire up the crossing, firstly depending whether you have one or two controllers, I understand that it will be manually operated as the diamond needs to know which controller is operating the section you wish to use. A single controller is easy to wire up, the difficulty arises if you use 2 differing controllers. The solution is to pair the diamond with only the upper or lower lines, then simply wire it as you would would wire a crossover (but with an extra double throw double pole switch.

 

The diamond is easy to wire as the polarity remains the same, the common crossings alter depending which route is chosen. What ever setup you have the diamond must be isolated from all the turnouts. The wiring will be much the same as a crossover, with the exception of a switch telling the diamonds common crossing which polarity they need to be depending on which route will be taken and they will always oppose each other

[AndyID]

21 hours ago, hayfield said:

 

I think what you will need to do is to isolate the diamond crossing from the turnouts

 

The difficulty comes when you wire up the crossing, firstly depending whether you have one or two controllers, I understand that it will be manually operated as the diamond needs to know which controller is operating the section you wish to use. A single controller is easy to wire up, the difficulty arises if you use 2 differing controllers. The solution is to pair the diamond with only the upper or lower lines, then simply wire it as you would would wire a crossover (but with an extra double throw double pole switch.

 

The diamond is easy to wire as the polarity remains the same, the common crossings alter depending which route is chosen. What ever setup you have the diamond must be isolated from all the turnouts. The wiring will be much the same as a crossover, with the exception of a switch telling the diamonds common crossing which polarity they need to be depending on which route will be taken and they will always oppose each other

 

Looking at the Peco picture the diamond seems to be fully isolated. I'll try to post a diagram.

 

I don't think you need any additional switches 😀

 

 

The frogs of the two upper points also supply the diamond's frogs as shown. The central sections of the diamond are permanently connected to the red and blue feeds as shown.

 

The top diagram is "straight through".

 

The middle one is NW/SE

 

The bottom one is SW/NE

 

To crossover you just set the required pair of points to "turnout" and set the other pair straight.

 

 

 

 

 

 

Edited September 11, 2022 by AndyID
Revisionist thinking

[Izzy]

3 hours ago, AndyID said:

To crossover you just set the required pair of points to "turnout" and set the other pair straight.

From a practical point this is probably as important to arrange as the wiring, which isn’t too difficult per se. Some method of working/interlocking that ensures both cross routes are not set at the same time for the correct electrical paths through the diamond.  Perhaps easier to arrange when using motors of some kind and difficult with separately sited mechanical levers.

[rab]

5 hours ago, AndyID said:

 

Looking at the Peco picture the diamond seems to be fully isolated. I'll try to post a diagram.

 

I don't think you need any additional switches 😀

 

 

The frogs of the two upper points also supply the diamond's frogs as shown. The central sections of the diamond are permanently connected to the red and blue feeds as shown.

 

The top diagram is "straight through".

 

The middle one is NW/SE

 

The bottom one is SW/NE

 

To crossover you just set the required pair of points to "turnout" and set the other pair straight.

 

 

 

 

 

 

Thanks AndyID

Exactly what I needed.

Edited September 11, 2022 by rab

[WIMorrison]

Don't forget the reverse loop you are creating in the dog bone under specific scissor conditions 😓

[RobinofLoxley]

Thank heavens I didn't plan on using one of these.

[WIMorrison]

Just now, RobinofLoxley said:

Thank heavens I didn't plan on using one of these.

absolute doddle wiring it with DCC - and the reverse loop it will create in this particular layout 😂

[RobinofLoxley]

1 minute ago, WIMorrison said:

absolute doddle wiring it with DCC - and the reverse loop it will create in this particular layout 😂

Lol. I studied the diagrams and actually came to the same conclusion. I just like to throw in some light hearted comments (as does dcb).

[Grovenor]

36 minutes ago, WIMorrison said:

absolute doddle wiring it with DCC - and the reverse loop it will create in this particular layout 😂

Yes, but rab is using DC and hence has to solve the reverse loop problem, not specifically scissors related a simple crossover would have the same problem. Not so bad if you always run through the reverse loops the same way, feed the loop through a bridge rectifier and reverse the controller while in the loop. But really you have to look at the whole layout wiring and control system. Looking at the scissors in isolation only works for DCC.

[AndyID]

4 hours ago, WIMorrison said:

absolute doddle wiring it with DCC - and the reverse loop it will create in this particular layout 😂

 

If you you want an easy solution 3-rail is the way to go, or even clockwork 😄