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 Some of the earlier pages of this topic are now out-of-date.

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    Some pages of this and other topics 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. All files derived from Templot are © Martin Wynne.
  • The Plug Track functions are experimental and still being developed.

    For an updated overview of this project see this topic.   For some practical modelling aspects of using Plug Track see Building 3D Track.

    The assumption is that you have your own machines on which to experiment, or helpful friends with machines. Please do not send Templot files to commercial laser cutting or 3D printing firms while this project is still experimental, because the results are unpredictable and possibly wasteful.

    Some pages of this and other topics 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. All files derived from Templot are © Martin Wynne.

Making a simple link

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bordercollie

Member
Location
Australia
Hi
I have progressed a bit further with timber shoving. I have designed the turnout carrage siding engine shed siding TR2206 on attached file with a curviform crossing but I am not sure if generic/regular or parallel would have been better. I can not remember why I selected curviform. I don't know if it was a mistake or whether there was a good reason. The main road and carriage siding are on a curve that starts at the exit of Tr2195. It looks OK visually to me but I am not sure if it is the best solution.
 

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  • Engine shed turnout 20.00 16.5.21.box
    56.1 KB · Views: 174
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@bordercollie

Hi Graham,

Where the diverging road swings back towards the main road, it is usually better to use a regular V-crossing. This minimises the effect of the reverse curving. This is especially the case where there is contraflexure in the turnout, as you have there. More info in this video:

https://flashbackconnect.com/Movie.aspx?id=pu2F-wveux5-EWGYuqPd3g2

In this case, using a curviform V-crossing, you have an instantaneous reverse (change of curving direction) at the vee joint. That wouldn't be acceptable in a running line, but for a low-speed siding connection, as here, it's not necessarily wrong:

graham_es1.png


On the other hand, changing to a regular V-crossing and making a full simple link does this,

graham_es2.png


causing the curve to extend into the Engine Shed and not fit through the shed doorway properly.

I suggest therefore using a regular V-crossing, but making the branch track dead straight. Then swap facing-trailing so that the rail-joint marker is at the free end (important), and slide the peg along it to a suitable tangency position (CTRL+F8 mouse action). Don't go too far, otherwise Templot will complain that a link curve won't fit:

graham_es3.png


You can then do make simple link on the Engine Shed track, with this result:

graham_es4.png


The branch track gets split at the peg, and a curve is fitted between the two. Leaving a reasonable length of straight track in front of the shed doors. :)

For these screenshots I added the Engine Shed via the sketchboard.

p.s. this is not about timber shoving, so I will move it to a separate topic shortly.

cheers,

Martin.
 
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Hi Martin

I have been trying to do as you have outlined. I have changed the "V" to regular.

I have found that the best fit was to set the peg at peg 1 on branchline. If I moved the peg much further along the branchline template than a few sleepers towards engine shed road I couldn't get it to work as you have shown on your screen shot. I either got error message or at best curved the wrong way. In the attached file the top layout shows what happens if I set the peg of the branchline at the junction with the turnout. The first duplicate shows the addition of a straight branchline. The the third shows what happens if the peg is placed as shown. The fourth shows that I get a invalid request message. What am I doing wrong? Is there anything wrong with the link as shown in top group? I have tried several things but I cannot get an out come as shown in your last reply.
Regards
Graham
 

Attachments

  • Simple link demonstration 24.5.21.box
    216.2 KB · Views: 154
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@bordercollie

Hi Graham,

The bit you missed is that I wrote:
Then swap facing-trailing so that the rail-joint marker is at the free end (important)

Like this:

graham1.png



I also extended the engine shed road so that I could see not to move the peg too far forward to leave room for the curve. The make simple link function will trim the engine shed track to fit:

graham2.png


When doing a simple link, Templot reads the the guide template direction from the Ctrl-0 datum end towards the Ctrl-1 joint end, so it's important to have the template the right way round -- joined to the previous template at Ctrl-0, and free end to be modified at Ctrl-1.

See also:

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

cheers,

Martin.
 
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@bordercollie

p.s. Graham,

To avoid confusion I have now changed the button to read "facing-trailng" when there is a turnout in the control template, and "swap ends" when it is plain track or a half-diamond:

swap_ends.png


Will be in 227b soon.

cheers,

Martin.
 
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message ref: 1509
Hi Martin
I have finally got it to work. I had swapped end for end in my previous attempts. However, my understanding of what you were describing was a bit off the mark. Now, having achieved a link as you described I was wondering if there is anything wrong with having a a continuous curve from the engine shed and turnout templates i.e. the top track plan on my original attachment. Would it make the timber shoving at turnout/ plain track junction easier. From your previous replies I can see that there was probably no preferred/prescribed way of doing things laid down by railway companies at the time, particularly in a siding situation.
Regards
Graham
 
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