From a standard turnout to a single slip - what do I need to know?

[Lacathedrale]

Hello there,

 

I'm just about to embark on laying down my first single slip - if I can crack it, then I've only got one more thing to succeed at (an asymmetric threeway) before I can say that i am fully equipped to deal with whatever a layout I'm thinking about building can throw at me. I've built a crossover and about half a dozen standard turnouts with varying success, though recent efforts have been significantly better and more reliable.

 

I'm building in 2mmFS rather than 7mm or 4mm and I have the tools available, I'm just thinking about order - the association book 'Track' is very useful in giving the basics but I can't find anything on slips, threeways, diamonds, etc. unless I'm going mad - so any pointers would be gladly appreciated.

 

Many thanks,

[Ian Smeeton]

My single slip build starts here:

 

A couple of 2 x 0.5 x 300 mm brass strips from Eileens, or similar emporia were  a great help.

 

I started with the first  'obtuse' rail, cut overlength, and then gauged the acute crossing from it using the brass strip to keep the line.

 

After that, everything just flowed along.

 

I know that you are a long way away, but Keith Armes (the track Guru) is appearing at  the next North Mercia Area Group meeting on the 7th April.

 

If you would like a lift from a station, Grantham, Newark, Retford, then I would be happy to pick you up and drop you back at relevant station.

 

Tony Wright has nabbed the other front seat, though.

 

Regards

 

Ian

 

[Lacathedrale]

Thank you kindly Ian, I'll be readingthat thread with eager eyes now   As for the NMAG, I'll see what the schedule holds but I've done a huge amount of travelling in the last few weeks so I'm hoping to have a bit of time to get on with doing... something!

[Izzy]

The only thing I would say is to double-check there is enough room at the blades for clearance and isolation cuts. I originally used a Templot template and had to substitute a 2mmSA one, (actually drawn by KA), the blades being set one sleeper further away from the tip of the crossings. This might be because I use etched chairplates on the pcb sleepers and just using rail straight onto them might allow more leeway. Martyn Wynne did post that there were settings in Templot to give wider blade clearance, and there are for D/Slips but not singles, but I couldn't seem to get it to work anyway.

 

Of course the fun with a single-slip - which doesn't occur with a double - is providing some kind of interlocking to ensure the correct polarity at the crossings.......

 

Izzy

[Ian Smeeton]

4 hours ago, Izzy said:

 

 

Of course the fun with a single-slip - which doesn't occur with a double - is providing some kind of interlocking to ensure the correct polarity at the crossings.......

 

Izzy

 

True, very true.

 

Something that I have been puzzling over for a few days, now. Hopefully, Keith, or Laurie, on Sunday, will have the answer for me, when I ask the question.

 

After all, they do have to do something to earn some of the Boss's Cake.

 

Regards

 

Ian

 

 

[hayfield]

First you will need an accurate plan/template, as the position of the tips of the vees is very important

I have found fitting the Vees first (if using copperclad construction) or the common crossing assemblies (if chaired), I double check the position with a straight edge to ensure all rails align  correctly 

Stock rails fitted next in turn using gauges and checking with straight edge (providing its not curved), dont forget to make set's in the slipped stock rail(s)

[martin_wynne]

6 hours ago, Izzy said:

Of course the fun with a single-slip - which doesn't occur with a double - is providing some kind of interlocking to ensure the correct polarity at the crossings.......

 

Hi Izzy,

 

You have lost me there. The wiring of a single-slip is exactly the same as a double slip -- and simple. The movement of the points at one end controls the polarity of the V-crossing at the opposite end.

 

Did you mean to refer to diamond-crossings? They are more involved because they don't contain any moving points, and are controlled by the setting of the adjacent turnouts.

 

cheers,

 

Martin.

[Izzy]

Hi Martin,

 

Yes, the wiring is exactly the same of course, double or single. It’s with the actual physical operation where problems can occur. I’ll try and explain what I mean.

 

With a d/s there are four routes, and it needs both sets of blades to be set correctly for any of them. Only one route is possible and the set of the blades indicates which it is. 

 

However, with a s/s while there are only three routes it is possible for both blades to be set for opposing straight crossings. This will give the wrong polarities for either. So some method is needed, some form of interlocking, mechanical/electrical, to make sure that while both can be set for the ‘curved’ route, only one at a time can be set for a straight one, to give the correct juice at the crossings. 

 

I have done this on my latest 2FS layout, Priory Road, by using a pivoting brass bar with the DPDT switches that mechanically move the blades, by having it so that while I can set both blades ‘curved’ ( sorry if that is the wrong term), both can’t be set straight. Should one pair be set straight and I change the other pair then this shifts the first pair.

 

I hope that make sense!

 

Yes, diamonds on their own are a nuisance with polarity. Even with other pointwork to control them it is often not that simple as regards ease of operation. On the above layout there is one sandwiched between the s/s and a turnout, and traps on it’s exit roads. I have made the traps work so they can each control a crossing polarity. Seemed the easiest solution.

 

regards,

 

Izzy

 

 

Edited April 1, 2019 by Izzy
Grammar corrections!

[Lacathedrale]

Where (if there should), the gap be on the wing rail on the common crossing which extends through as a single unit to end in the point rail of an obtuse crossing? Pic attached.

 

The Track book suggests a certain location but is in the context of a diamond rather than a slip - I feel like I'm going to have a very tiny common crossing assembly, encroach into the area of the switchblades, or have a very tiny piece of rail at the end of the point  rail.

[Izzy]

Couple of shots of my latest efforts, which may help, or not......  As said previously I used the 2SA A6 template, the timbers seem arranged slightly differently and gave me what I thought was more wriggle room, but looking at your Templot one I can't see much difference now.

 

 

There isn't much room to lay the etched chairplates, the slidechair one as well as a normal, just about enough space to make the needed isolation cuts.

 

Hope they are of use.

 

Izzy

[Lacathedrale]

That's perfect, thank you - I was concerned that two sleepers past the knuckle of the wing rails might not be enough, but clearly no problem. Much appreciated!!

[martin_wynne]

7 hours ago, Izzy said:

As said previously I used the 2SA A6 template, the timbers seem arranged slightly differently and gave me what I thought was more wriggle room, but looking at your Templot one I can't see much difference now.

 

Hi Izzy,

 

It's important to understand that the timbering layout in Templot is entirely under the user's control. Looking at someone else's Templot template doesn't mean that yours will be the same, or needs to be the same.

 

There are some default settings which Templot uses, but only if you don't change them. A template could easily be modified to match one obtained from elsewhere.

 

Templot is a workshop tool -- what you choose to create with it is entirely up to you.

 

cheers,

 

Martin.

[Lacathedrale]

Getting there slowly

[Ian Smeeton]

Looking good so far.

 

What about Sunday, any thoughts?

 

Regards

 

Ian

[Lacathedrale]

Ian, it's a very kind offer but really a bit too far  - thanks again

 

 

[Lacathedrale]

I don't think I'll ever be able to figure out how preceisely to gap these sleepers - I thought it was perfect but had to reshuffle the layout a little, and now there's a 2mm gap, enough for a wheel to drop in and almost derail a wagon

[Lacathedrale]

I have totally lost my place with this, after having it packed away for a couple of weeks

 

Any help on what I should do next? The other straight stock rails? The left hand closure rail? The switch blades?

 

Edited April 24, 2019 by Lacathedrale

[Izzy]

Personally I would do the LH closure & blades ( as one piece), as from them the other stock rail can be gauged, followed by the other blades.

 

Izzy

[Grovenor]

Do the curved switches inside the diamond next, then you will have something to gauge the curved stockrails from. Leave the straight switchblades to last.

Rgds

PS personally I always do the curved blades in two pieces, its easier to cut to length at the central joint after filing, If you make in one piece and its a bit short you have to file again.

Edited April 24, 2019 by Grovenor

[Lacathedrale]

Thank you both - I'll do that. Looking at a wiring diagram I've seen online here though, the LH closer rail/switchblades look like they are going to need to be in three isolated sections: http://www.stciers.me.uk/home/track_wiring/s_slip.htm

 

That diagram doesn't include the obtuse crossing knuckles but seems to show roughly where the polarities need to be?

 

Is that right? Seems to go against @Grosvenor 's suggestion of doing it in two pieces (unless the suggestion is to start with two pieces and then bisect each!)

[Lacathedrale]

Ah, I think I may understand - the difference between the diagram above and your (Izzy)'s slip, is that like me you've got an insulating break much closer to the vee, so the whole assembly of stock rail, point rails, knuckle, closure and switchblades can all be electrically joined and at the same polarity, right?

[Izzy]

Yes, that’s right. Much easier and simpler to arrange. Basically the same as an ordinary point, split down the middle and the crossing(s) separate from both. Works for diamond/ SS/ DS.  The wiring dia you have linked to might be concerned with some make of ready made track. Often from what I have seen they appear to be made up of multiple individual bits bonded together electrically as needed.

 

Izzy

[Lacathedrale]

Against all odds, it appears to work through the curved route, and when set in place the straight routes are fine too! Huzzah! Unfortunately, I think I've provisioned too short a piece for the remaining switch blades. I'm happy to consider this a victory and move on to the 'real' version, unless there's some obvious way of fitting them to gauge/etc. given the rail opposite:

 

[Ian Smeeton]

Should be do-able, if you cut bach the rails from the K crossings by a couple of sleepers. Top one looks OK, just the bottom one.

 

Regards

 

Ian

[Grovenor]

Agreed, you need to cut back the K crossing rails, both ends i think, by 2 sleepers to allow each blade to be soldered to 2 sleepers the same sleepers as the first 2 soldered to the curved switches.

Best to complete it so you also get practice with the drive stretchers.

Rgds