Code 75 fishplates - Curve issues.

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Nigel,

We're in agreement regarding the expansion coefficient of the rail, my data in the earlier post was for Nickel Silver but there's not much difference to the figure you cite for brass.

Where I'm a little puzzled is the sleeper bed issue you raised. In my experience flex rails move freely in the chairs so no binding likely due to differential expansion and the sleepers do not extend to the rail end but some 2-3 mm short depending on the track. If there is a little bud protruding off the end of the final sleeper that could be nipped off if expansion is a concern.

Colin
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Colin

You would think so, especially as most track gets glued down. However, track gets ballasted, painted, sealed….all of which lock the rail to the sleeper. Which got me thinking about expansion of the gauge….

N/S isn't that far from brass, hence the reason I didn't bring it up. I do recall this topic was actually discussed several years ago.

The other factor of course is the expansion and contraction of the wood base/frame with changes in humidity (major) and temperature (minimal). Up to 0.5"/48" depending on the wood/grain direction (one good reason for using plywood for the frames and the top, more resistant to humidity changes). Closed cell polystyrene foam is not immune from temperature changes either - up to ± 0.25" for a 4 foot long piece. Plus it shrinks as it degasses.

Mike, getting a bit off your question, but when you get the joiner issue sorted, make sure to leave expansion/contraction gaps between the rails if you experience wide fluctuations in humidity and temperature. To address an earlier question from 'Petermac, continuous/ribbon rail has expansion joints every now and again, they just happen to be diagonal, allowing the rails to slide across each other. No reason why this can't be done in 1:76 scale.



Nigel

©Nigel C. Phillips
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BCDR wrote:
continuous/ribbon rail has expansion joints every now and again, they just happen to be diagonal, allowing the rails to slide across each other. No reason why this can't be done in 1:76 scale.



Nigel
It was done in OO.  Peco offered an expansion joint in their Code 100 Streamline range part number SL-44.  These are now discontinued, or are at least out of stock everywhere, and I suspect did not sell well.

They did what they claimed to do namely acted as an expansion joint.  I used four on my Australian layout at locations particularly susceptible to high outdoor heat.  The problem I had was that they relied upon contact between the two separate pieces of rail for electrical continuity.  Just as with point blades that wasn't 100% reliable but unlike point blades it wasn't possible to clean the opposing faces where they touched.  

I tried RailZip and Electrolube in addition to the track rubber and I even tried shimming a piece of wet and dry between them - which wouldn't go in never mind have any effect - meaning the only solution remaining was to electrically bond the rails by soldering connecting wires across the gap.  




Rick
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[user=2233]1867Adelphi[/user] wrote:
Hi everyone.
I'm in the process of building my first layout and I'm at the track laying stage………….

Any help appreciated!
Mike
Hi Mike,

Just wondering if the various response posts here have proved to be useful for your modelling or perhaps you've been distracted at work by matters and the terrible events playing out 1200km north of you?

Will be good to hear from you, whatever.

Colin


 

 

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Thanks a lot for your replies guys. Yes, they were very useful and I've made good strides.
I've certainly made use of the tracksetta tools. I'm still having moderate difficulty with getting fishplate/joiners on the streamline code 75 track although filing certainly helps.


One day I'll settle on a trackplan….
but likelihood is it won't be today!
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Make a tool to push on the fishplates Mike - they can be very difficult to push on.

A length of rail stuck in a handle of some kind and a fishplate soldered on leaving half a fishplate length clear at the end.

Doug Dickson (chubberdog or dooferdog - not sure which name he used at the time) showed the way - a neat, easily made aid which I find invaluable for the later Peco fishplates which seem tighter than the old type.

I'll see if I can find the post or if not, I'll post a photo of mine.

'Petermac
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Here's the details of the fishplate fitting gadget Mike (hopefully !) :


http://yourmodelrailway.net/view_topic.php?id=10140&forum_id=149&highlight=fitting+%3CSPAN%20STYLE=

'Petermac
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