Templot 4-SF Tandem - short wing rails and peco geometry

[Lacathedrale]

The following is a tandem turnouts in 4SF - It is a standard B6 derived tandem with the lower/left road exiting at 12 degrees to match the standard Peco bullhead pointwork I'm using elsewhere:

 

 

 

However as you can see, the middle crossing's right wing rail is miniscule. In practise I would probably plane off both sides of the rail to extend it into the nook of the crossing - it just feels very small!

 

[hayfield]

Click the button marker Real, the second from bottom of the dialog box is marked adjust check rails. Either MS3 or TS3 box will be next to the wing rail, press the one you need to adjust and try altering the length and shape using the buttons and mouse. However your ability to alter it is very limited due to the lack of space

[Lacathedrale]

Thanks John - that's what I've done to get it as small as you see - I changed from bent to machined and reduced the flange length - it originally overlapped the adjacent switch rails. I think, looking at the Peco equivalent, that this might just be a limitation of a fairly sharply curved tandem turnout - I guess one has to hope that the topmost wing rail is doing its duty!

[martin_wynne]

Hi William,

 

A few adjustments are still needed.

 

Your wing rail at A is too long and does not leave a clearance for wheel flanges on the adjacent running rail. You need to shorten it to a minimum, like this:

 

 

(To shorten a rail to a minimum, you must first shorten the flare length to a minimum.)

 

It will continue to work fine as a wing rail provided the unflared portion (in yellow) reaches at least beyond the nose of the vee. A practical minimum is to have it reach at least the centre-line of the timber supporting the nose of the vee.

 

Also, your check rail at B is too short. Wheels arriving at B from the right must be under the control of the unflared portion of the check rail (in yellow) before the opposite wheel reaches the knuckle bend in the wing rail. You need to lengthen it as above.

 

Here's a prototype pic from the Scalefour Soc showing a wing rail machined to clear the adjacent running rail:

 

© linked from: https://www.scalefour.org/resources/trackdetail/chairs04.jpg

 

cheers,

 

Martin.

Edited January 7, 2020 by martin_wynne
photo added

[Lacathedrale]

Thank you Martin, changes duly made. Do  you have the functionality in Templot to illustrate that special machined wing rail?

[martin_wynne]

6 hours ago, Lacathedrale said:

Thank you Martin, changes duly made. Do  you have the functionality in Templot to illustrate that special machined wing rail?

 

Hi William,

 

That's not directly supported, but it is not difficult to do if needed:

 

1. set the required flare length and/or end-gap, and a machined end.

2. wait until the track design is finalised, as with shoving timbers, etc., otherwise you may need to do it all over again.

3. split out the machined end of the wing or check rail as a separate partial template.

4. set peg free, and then move the peg manually to the start of the flare (CTRL+F8 or 8 mouse action).

5. rotate the end of the rail around the peg as required (F8 mouse action) and/or adjust the end-gap at the same time, like this:

 

 

 

6. store it, and ideally add a prefix tag so that you can easily group the two templates later if needed.

 

When you get into Templot at this level, it is better to swap to the Templot Club forum, rather than RMweb. For example my previous comments about adjusting the wing and check rails were covered in greater detail in this topic:

 

http://85a.co.uk/forum/view_topic.php?id=2555&forum_id=1&jump_to=17633#p17590

 

cheers,

 

Martin.