Scalefour Forum

Hi Peter,

I changed my diamond to a switched type, I only made 5 new crossing timbers if I remember which was not totally accurate but it looks and works okay. Without knowing the curve radius you cannot use the chart that Martin posted, but a switch diamond is a safe bet.

Regards, Tony.

TonyMont wrote:Hi All,

I had set myself another target. To get a train through to Buxton before I start to disassemble the layout for our house move (no purchaser yet) so here is a video of progress so far. https://www.youtube.com/watch?v=rb5hY6C ... e=youtu.be
Many other junctions are ready for installation but it is very time consuming and all the track on the Buxton side is temporary so far.
I hope you enjoy the video, and let me know what you think.

Regards, Tony.

Amazing footage of an extraordinary layout, I wish Cyril Freezer could have been alive to see this!

Thanks for posting

Steve

steve howe wrote: I wish Cyril Freezer could have been alive to see this!

And it might prove a thing or two to Tony Wright as well. Except of course it is not a "fast" main line with large engines painted in BR green.

Terry Bendall

Terry Bendall wrote:

steve howe wrote: I wish Cyril Freezer could have been alive to see this!

And it might prove a thing or two to Tony Wright as well. Except of course it is not a "fast" main line with large engines painted in BR green.

Terry Bendall

Interestingly, I note he was one of the judges who unanimously gave Sandford & Banwell the cup at the recent CMRA Stevenage show .... also being very complimentary about the faultless running. so twice recently blinkers haven't clouded judgement

Hi All,
Most of the layout is in storage, but as a house move looks to be waiting for Brexit I have erected Buxton Midland station boards, with the idea of at least getting something done.
At the entrance to the station is a scissors crossing with a tandem turnout on one corner, building it will be fun no doubt but I have two questions, first which crossing vee would be the first to fit and where to from there.
Second it will be operated through an interlocked lever frame so no conflicting switching can occur, but I am struggling to work out where bonding and rail breaks are required, has anyone any experience?
Regards,
Tony.

The crossing vees in a scissors have to be built as sets, so which is first is not answerable. To ensure you keep the track centres correct start with the two outer stock rails then do the crossings, takes a lot of care to keep the gauge correct through the crossovers.
If you have the drawing done, Templot? I can use it to show the required bonding and rail breaks. I will need to know if it is all one section (DCC) or if any section breaks are required (DC or DCC power districts). Could also show on a plan the build sequence I would use, a lot easier than trying to describe it.
Rgds

Hi Keith,
Thanks for the quick response, the layout will be dcc and the station will be all one district I think.
I cheated with the Templot, I overlayed points to get what I wanted but did not remove duplicate rails so it is very messy, I am actually building off a Protofour template. I suppose I could lift a template off the Templot club site. I will have a go.
Regards, Tony.

TonyMont wrote:I suppose I could lift a template off the Templot club site. I will have a go.

Hi Tony,

There is a downloadable Templot file for a scissors crossover at:

http://85a.co.uk/forum/view_topic.php?i ... forum_id=1

(It's EM and curved, but will serve the purpose.)

cheers,

Martin.

Hi Martin,
Thanks. I had just found one, but the one you suggest is clearer.
Tony.

TonyMont wrote:Hi Keith,
Thanks for the quick response, the layout will be dcc and the station will be all one district I think.
I cheated with the Templot, I overlayed points to get what I wanted but did not remove duplicate rails so it is very messy, I am actually building off a Protofour template. I suppose I could lift a template off the Templot club site. I will have a go.
Regards, Tony.

Ok, If you are using a standard template that will do, if you can explain where the tandem fits in.

Hi Keith,
If you can imagine the top left point is part of the tandum, an overlayed B8 branches to the right. If that makes sense.
Regards,
Tony.

As above, I'll get on it later today.
Rgds

Hi Keith,
Yes that's the one, it has been modified a few times, since I posted the original plan, but essentially the same arrangement.
Attached please find a scan of the template I am using and a photo of a class 25? on the tandum.
Regards, Tony.

Tony,
That's great, I can work on that scan.
Regards

Ok attached is the isolation and bonding plan. Rest to come tomorrow.

Rgds
Keith

Doing the timbering under the Tandem is going to be interesting.

Herewith crossing switching diagram, more tomorrow.

NB Only one crossover to be reversed at a time, otherwis there will be shorts on the diamond when a train tries to cross.
Points 1 & 3 work together as a crossover, same for points 2 &4.
1 & 3 lock 2 & 4 - required to prevent shorts (prototype does it also to reduce risk of collision).
5 locks 2 & 4 - optional on model (prototype usually does it to simplify locking design).
Rgds
Keith

Hi Keith,
That will all take some time to digest, but thank you. The forum in general and you in particular are fantastic resourse.
Best regards,
Tony.

Here are a couple of pics of the closest I have to what you need, the tandem is similar but the scissors is non standard. And the board is currently under modification.
Build sequence to follow later.

Herewith diagram and notes relating to a build sequence.
Get back to me if you have any queries.

Build sequence

First essential is to establish a clear baseline so start with the straight stockrail, item 1 on the diagram.

Then its decision time, one option is to establish the track spacing by putting in the opposite stock rail, item 2. This means that when preparing the central diamond great care will be needed to get the correct gauge in the crossing routes, you may need more than one attempt at the two triangular crossings, items 3 & 4 as these have critical dimensions.
The diamond rails, items 5, 6, 7 and 8 are needed to check the gauge and alignment.

An alternative is to work your way across, installing 3, 7 & 8 then 4, 5 & 6, followed by rail.
The problem here is that any error will result in rail 2 being off centre on the rivets so its 6 of one, half a dozen of the other.
On balance I would go with option 1. But you need to be comfortable with it.

Once these 8 rails are in place and checked the hard work is done. I would go to the easy end next and add rails 9 and 10 follwed by 11, 12 & 13.

Then do similar work at the other end modified as necessary for the tandem.
Once the skeleton is in place work through the wing rails, then check rails and finally the 10 blades.

Within any turnout I do the curved closure, eg rail 9 before the curved stock rail, eg rail 12 so the latter has something to gauge from. Don't forget the setts in the curved stock rails.

Regards

Hi Keith,
My version of the bonding, feeds and locking was similar to yours before I asked the question. I have obviously not built anything as complex as this before, and yours looks brilliant it must be very satisfying to watch trains travel over it.
I have one problem in my theory, if turnouts 1 and 3 are switched to crossover they will change the polarity of crossings A and B, but if A and B are connected to 2 and 4 also then does this not cause a short? Is there something I am not getting?
Best regards, Tony.

Tony,
Crossing A is switched to either X or Y, it cannot connect to both at once.
The switching uses contacts on 1 and 4, if both 1 and 4 are normal then A connects to Y for straight running, if either 1 or 4 are reversed then A connects to X. Sinilar arrangement for B.
The trickier bit comes with C and D. With all points normal they are not used so the connection doesn't matter.
With 1 and 3 reverse then C connects to Y and D to X, with 2 and 4 reverse then its C to X and D to Y, all good.
If all 4 points are reversed then C remains connected to X and D to Y so you can run through via 2 and 4 but running through 1 and 3 will find C and D at the wrong polarity and cause a short. ie the diamond cannot be both ways at once. This is why interlocking is needed.
Regards

grovenor-2685 wrote:Tony,
... ie the diamond cannot be both ways at once. This is why interlocking is needed.
Regards

Apologies if I missed mention in an earlier post, but how are the points to be operated?
If mechanically the solution is clear as it should be if using computer control.
However if using point motors and switches you may like to consider a rotary switch. I’ve used three way ones, anti-clockwise for top-left to bottom-right reversed, centre for all normal and clockwise for bottom-left to top-right reversed. Works with a 12 (3*4) pole switch... but I haven’t considered adding signal interlocking!
The same concept also works with a bi-directional loop line between two running lines, essentially also two crossovers where it is only permissible for one to be reversed.

Yes, I use rotary switches for simple point interlocking, the junction in my photo above just has a single 4 position switch. The switches come with 30 degree steps so you can make the diagram with matching angles.
Regards

Hi Keith,
Thanks, I think I have got it sorted now, I think the dcc wiring does make it simpler and I had not got my head round it.
Regards, Tony.