• The Plug Track functions are experimental and still being developed. Some of the earlier pages of this topic are now out-of-date.

    Some pages of this topic include contributions from members who are creating and posting their own CAD designs for 3D printing and laser-cutting. Do not confuse them with Templot's own exported CAD files.

Layout ideas exploration

Carlos

Member
Location
Cambridge
Hi Martin,
I followed your very good video about importing maps from NLS, and I follow it to generate my own. I managed to create the following one (Earith Bridge on the Ely to St. Ives railway). I'm exploring ideas to create an easy layout, and this seems simple enough, with a nice water feature ad small bridge (perhaps too boring track?). In any case, I would like to shorten it a bit (it is about 3.5 m in 4mm, 3 m would be great), and two methods come to my mind:
1- scale the background in the x direction only (but this will reduce the buildings, and, of course, will modify the turnouts shape)
2- cut and remove a section from the centre

Is one of these methods best? there are other methods? and how can I apply it in Templot?

Thanks,
Carlos
midland_central__neg4872_neg4002__360042_53081__2022_07_20_2126_52.png
 
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Martin Wynne

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Location
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Enjoy using Templot?
Thanks.

Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add
helpful replies.
would like to shorten it a bit (it is about 3.5 m in 4mm, 3 m would be great), and two methods come to my mind:
1- scale the background in the x direction only (but this will reduce the buildings, and, of course, will modify the turnouts shape)
2- cut and remove a section from the centre

Is one of these methods best? there are other methods? and how can I apply it in Templot?
@Carlos

Hi Carlos,

Welcome to Templot Club. :)

There are several ways to make a track plan from a map fit the available model space -- only you will know which suits your model best.

3. a popular way is to curve a long narrow map so that it fits into or across the corner of the railway room. Templot has a function to wrap a map image along a curve for that purpose:

wrap14.png


Here is a tutorial on how to do it:

https://85a.uk/templot/companion/wrap_picture_shape_to_curve.php



1. your first method, to shrink the image lengthwise only, is the easiest to do in Templot. modify shape > change dimensions... and change only the X dimensions. Or use the corner 1 and corner 2 mouse actions. The image is always stretched to fit the picture shape rectangle which contains it.

The disadvantage there is that the turnout sizes and angles will change, buildings will be distorted, platform lengths will be reduced, etc. Also circular curves will become elliptical, although with typical prototype track radii probably not by enough to be a problem in the model. But elliptical turntables are problematic. :)



2. on balance I would go for your second method, to trim section(s) out of the map. This preserves the sizes and relative positions of pointwork formations, buildings, bridges, platforms, etc. It does mean that the capacity of loops or sidings may be reduced. It is also more work to do than a simple stretch.

Here I have done that on the Earith Bridge map, reducing the overall length to 3000mm:

carlos_earith1.png


The BGS3 file for this is attached below.

As you can see the Signal Box has got lost in the process, and would need to be reinstated somewhere in the middle. Also the length of the loop line is reduced, but still adequate to shunt the sidings. The sections at each end are unchanged from the original.

The running line is curved, so there is a need to calculate the angular offset caused by removing a section of it. To do this I first placed a dummy template on the original map, to find the ruling radius, which was 12000mm (at 4mm/ft) in round figures.

You wanted to remove 500mm from the length, so the angle turned along the removed section would be 500 / 12000 radians x 180 / Pi = 2.39 degrees. This is the angular difference needed between the two end sections of the map in order to re-align the curve after 500mm has been removed from between them.

Here I have made two copies of the map and used the twist function to get them to a convenient screen alignment. The first one was twisted by 40 degrees. The second one was twisted by 42.39 degrees, so that there is a difference of 2.39 degrees between them.

carlos_earith3.png


I then used the crop/combine function on each of them, arbitrarily using the right-side of the signal box as the split line. Then using the shift functions I overlaid them with a 500mm overlap:

carlos_earith2.png


Then optionally crop/combine again to produce a single picture shape, as the first screenshot above. Here below is the file for it (4mm/ft).

More about the crop/combine function: https://85a.uk/templot/companion/crop_combine.php

cheers,

Martin.
 

Attachments

  • earith_bridge_4mm_shrink_overlay.bgs3
    1.7 MB · Views: 12
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Carlos

Member
Thread starter
Location
Cambridge
Thanks Martin!
That's impressive, you found time to understand my question, to fully and clearly answer it, and then you also did my homework!
That was exactly what I was looking for, methods to modify the plan to adapt it for a layout. Method 3 is impressive too, but perhaps not applicable to my current needs, but good to know it. Method 1, the easiest as I suspected, changes the geometry (an elliptical turntable seems more problematic than a "compressed" building). And method 2 seems to do the trick this time. I was thinking on a more lineal way, which would produce a 2 degrees "kink" in the track, but the rotation method (like a hand fan...) is better. I think I understand the method, and it will be very useful (including the trick to find the curvature radius).

Well, no excuse now to continue playing with it (up to now, I had only used Templot myself to print a standard template to build a turnout)

Carlos
 
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Martin Wynne

Admin
Location
West of the Severn UK
Info
.
Enjoy using Templot?
Thanks.

Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add
helpful replies.
Thanks Martin!
That's impressive, you found time to understand my question, to fully and clearly answer it, and then you also did my homework!
... ...
I was thinking on a more lineal way, which would produce a 2 degrees "kink" in the track, but the rotation method (like a hand fan...) is better. I think I understand the method, and it will be very useful (including the trick to find the curvature radius).
@Carlos

Hi Carlos,

You're welcome. :)

I should have mentioned that Templot will do the angle calculation for you, if you prefer not to dab a calculator. If you set the dummy template to match the map radius, and set the overall length of the template to the amount of map you wish to remove, the angular difference is shown in the info as the swing angle:

swing_info.png


Also, when I wrote "I overlaid them with a 500mm overlap" I was rather skating over the details. The actual amount of overlap will vary with the radius, and the angle of the tracks on the screen. Again, the dummy template can be used to show the amount of overlap needed.

I will make a bit of video showing the process in greater detail, as it is likely to be of interest to all.

cheers,

Martin.
 
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Carlos

Member
Thread starter
Location
Cambridge
Thanks again, Martin! I'm looking forward to try it myself, to check I understood.

Carlos
 
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