Building Track Upside Down

[lucas]

I have intermittently dabbled in railway modelling for the last 15 or so years, but seeing my dad's (nearly) complete OO9/HOe Dutch steam tramway has given me the itch to do some more modelling of my own. Of course having grown up in Cork I have very little nostalgia or even knowledge of Dutch trains, so I thought I should have a go at some Irish trains instead.

Unfortunately I don't really have the space for proper layout in my current apartment, but I'm set to be moving to a bigger house in around a year or so I figured I'd get started with some rolling stock in anticipation. And just to make things difficult for myself I wanted to have a go at modelling with 21mm gauge, which means I'll need a short stretch of 21mm track on which to build and test those models.

Having read about a few different methods of building track, it always seemed weird to me that track is built sleepers first with the rails fixed on top. In my engineer brain it always seemed more logical for the rails to be held in place with the correct gauge (since that is the important dimension) before the sleepers are attached to the bottom. Now admittedly I am an electronic engineer, so my engineer brain could easily be very wrong with something like this. But I wanted to give it a try anyway.

First I 3D printed a jig to hold the rail in place. Actually, I printed 5 different jigs because it took a while to get the dimensions just right. It needed to hold the rail snugly at the correct gauge, and as it turns out my printer just isn't that accurate.

Here it is holding the rail in place. I'm using regular Peco code 75 track which has been destroyed disassembled for this experiment. In the background you can also see some of the failed prototype jigs. Actually I think the one holding the rail in this photo was also replaced by another revision because the track gauge was a little off.

The final revision jig holding the chairs in place. These are incredibly fiddly to get onto the rail, but I reckon when I get to building a full layout I'll opt for bullhead rail so it might be different. Or I'll opt for another track building method, I'm not sure yet.

I had a friend with a laser cutter cut some sleepers out of thin wood. I couldn't find good dimensions for the sleeper width and spacing so I eyeballed it. These are 3.5mm wide with 10mm centre-to-centre spacing, and look pretty good to my eyes anyway.

The sleepers were glued to the chairs with poly cement, which in my testing creates a good enough bond between plastic and wood. It also doesn't stick to the PLA plastic of the 3D printer, so no fear of accidentally gluing the track to the jig.

Using a heavy book to hold the sleepers in place while the poly cement dried.

The first set of sleepers after the glue has set.

I placed the last sleeper of the previous set in the jig to align the next set of chairs and keep the spacing consistent.

Checking the track gauge. 21.01mm is what I call close enough.

The finished length of track, glued into place to a scrap piece of chipboard.

Close up of the track. You can see one of the sleepers is not quite perfectly aligned. Since they are not glued onto the rail itself they do have a tendency to move around a little bit, but it's not noticeable enough to be a problem.

Now this is a simple straight piece of track, you might be wondering how would this work for curves, never mind points. For curves it should be relatively simple since the sleepers can slide around along the rail it can be used like a piece of flexi-track and bent to shape. For points on the other hand... that is a very good question. Since I won't need to make any for another while I guess we'll cross that bridge when we get to it.

Another potential pitfall of this technique is speed. While it does take some time to thread the chairs onto the rail and align everything, I was mainly limited by the drying time of the poly cement I used. This meant I could effectively only do 8 sleepers in a session. This could be alleviated by using a larger jig, or with multiple jigs doing multiple lengths of track in parallel.

Anyway, overall I'm very happy with the result. Now it's time to put this test track to use regauging, modifying, and scratch building some trains.

~Lucas

[Mayner]

Great example of latheral thinking, finished track with laser cut sleepers looks great. Now the challenge of designing jigs suitable for curving track, points etc.