What is "Fish centre" How is the fish angle measured (between what).
@timbersgalore
Hi Timbers,
Tightening the
fishbolts wedges the
fishplate between the angled
fishing faces, putting the rail web in tension. Ideally sufficient to ensure that it doesn't become unloaded under the traffic load. Otherwise the bolts would work loose:
Note that there is a space between the back of the fishplate and the rail web, otherwise the system doesn't work. The same applies to the
fishwashers and spacer blocks which are used on bolted crossings.
The fish angle on all UK REA bullhead and jointed flat-bottom track is 1:2.75. Here is the way the rail is dimensioned:
BS-95R prototype dimensions in red. The dimensions in black relate to a sample of C&L rail from AndyB at the time that drawing was made, and taken from this old 2016 topic:
https://85a.uk/templot/archive/topics/topic_2734.php#p29639
You can see that the all-important fishing faces are dimensioned from their intersect on the rail section centre-line. The head and foot depths can then be derived if needed.
n.b. the dimensions in black are NOT metric equivalents of the dimensions in red.
Here is a bit of Exactoscale steel rail, and you can see why I estimated the model fish angles to be much steeper than the prototype:
I found the Templot chairs quite a sloppy fit on the 4mm society rail. I would say you have overdone the allowance for rail side taper. It would be helpful the know what are the profile numbers for "C&L / EMGS/ S4Soc code 75" rail.
Thanks for the feedback. The chairs which I printed here are a nice close fit on the Exactoscale steel rail and maybe a fraction loose on the C&L nickel-silver rail which I have here. But in both cases the rails are from old stock which I have had for many years, so feedback about current production rail is valuable.
I want to emphasize again that everything related to 3D track which I have released so far is
utterly experimental. There is no guarantee that any of it is correct, or workable, or will remain unchanged in a final release. I released it only so that folks could see my direction of travel, maybe join in with some experiments, and provide valuable feedback. There was no intention that it should be used for any actual modelling, because almost certainly it is
wrong. The object is to first prove the concept of Plug Track, and if successful only then go back and make it an accurate model of anything.
If/when the whole thing works, I will then make fresh drawings as above showing how everything is dimensioned and provide some recommended settings. The settings in the program at present are not a recommendation of anything.
cheers,
Martin.