This Blog will tell the story of my modelling the NSWGR location of Gunnedah in HO scale, along with other modelling content.
Monday, February 15, 2010
The Finer Points of Making Finer Points?
Is it just me, or does anyone else feel the need to use catchy phrases for their blog updates? Anyway ..........
With Sydney's crazy humid weather continuing, doing anything more physically active than blinking leaves one in a lather of sweat, so it seemed a good time to sit back at the modelling desk and build another set of points.This is the first set I've built using code 55 rail, which in all honesty was not much different to the code 75 rail I've used before. If anything I think the Micro Engineering code 55 rail is made of harder metal than the Peco rail as filing it seemed to be harder by comparison.
Apart from the change in rail, this set was built using slightly different dimensions to the NMRA specs. Terry Flynn has published some dimensions which theoretically (and have been proven) allow your typical RTR RP25/110 wheels to happily run through the points, and also allow the finer RP25/88 wheels to run through without any wheel drop through the frog or crossing V area.Basically the gauge is set to 16.26mm as opposed to the std 16.5mm, and flangeways can be set to 1.0mm, making a visual improvement over the wider dimensions actually used, and actually aids smoother running through the points.
Without the aid of any gauges to aid construction due to the different dimensions added a slight difficulty factor, but apart from some extra time it all went fairly smoothly, and I was very pleased to run a couple of sets of bogies through the points at various stages with excellent results.There's a degree of backwards engineering going on here as well, as I will use this set of points to try to get some roller gauges made to aid in the building of points to these dimensions which so far I'm very impressed with.
Another item of these points which I have had a bit of a tinker with is the tie bar. A lot of hand lai points simply use a pcb sleeper as the tie bar, which is strong, easy, and apart from the visual aspect of a whole sleeper sliding along when the points change route, it's a proven design.However, looking at the real thing, the tie bars are quite thin, and do not project outside the stock rails obviously.
What I've done with this set, it use a pcb sleeper, but cut it to length so it's just long enough to sit underneath the stock rails and only project out a maximum amount equal to the the trow of the swith blades, and I've filed down the centre section as narrow as possible to make it look more like the proper tie bars.
This first one is a little rough and not 100 percent in the right position as the tie bar needs to be centred between the sleepers a bit more, but that's nothing a quick hit with the soldering iron won't fix. Even filed down to this size it's still quite strong, and really looks quite good, or is at least a big improvement over the full sleeper look. There's very little pressure put on the tie bar anyway so I don't foresee any problems with it breaking. It will mean a slightly different method of attaching a wire to move it from side to side but that's nothing too hard.
As you can see I've also put up a pic of three different pieces of rail, Peco Code 100, Peco Code 75 and the Micro Engineering Code 55. In my mind, and logically, I know that code 55 is just over half the height of code 100, but the overall effect is actually more dramatic, with the rail actually looking more like a quarter of the size of code 100, as it's not just the height, but the width that is proportionally smaller as well. For a branch line style layout, the code 55 really does look a treat, IMHO.