Ztrains: Z Scale Basics: Track Geometry

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Developing A Track Geometry

Initially we'll be looking at some very basic track plans you can quickly and easily assemble to get your trains on the move. We'll be using MTL's Micro-Track® sectional track for these plans. Before we even look at a track plan however it's worthwhile to briefly touch on sectional track geometry. Now track geometry simply refers to the size, shape and relative position of our sectional track pieces. That seems easy enough.

Micro-Trains developed their sectional track pieces based on the original Marklin metric-based track geometry of the early 1970s. The three major curve radii were 145mm, 195mm and 220mm. In addition there was a 490mm curve radius which was often used in tandem with turnouts and for creating very broad curved sections. By developing a track system based on the existing Z scale standards MTL has made incorporating their Micro-Track® into existing layouts very easy. In addition many track planning software packages include a Marklin Z scale track library... by using the available Micro-Track® pieces that have the same geometry as the Marklin pieces in these libraries, you can plan your Micro-Track® layout using today's most popular track planning software.

Currently Micro-Track® has all these curve radii available except for the 145mm curves. When Z scale was first introduced there were many small locomotives that worked well on a 145mm radius curve. With the more prototypical locomotives of today however a 145mm radius curve could present running issues and as a result, Micro-Track® is not available in this radius.

Next Up... Degrees

We know that Micro-Track® curved track sections are available in several different radii but there is another number we have to consider... the degree of the track piece. Along with the radius, each piece of Micro-Track® curved track also carries a number expressed as a degree. This degree is simply a percentage of a full circle of track. Micro-Track® curved track comes in several varieties of degrees depending on the track radius... 30, 45 and 13 degrees.

This might sound more complicated than it really is so we'll use the chart at the right to illustrate. In this simple track plan we're using the Micro-Track® 195mm curved sections to build a circle of track, a favorite for trains under the Christmas Tree!

Though all the track sections have a 195mm radius, their degrees are different. The track sections on the left side of the circle are 195mm, 30°. The track sections on the right side are 195mm, 45°. In this illustration all this means is that we'd have to use 6 pieces of the 195mm, 30° track and 4 pieces of the 195mm, 45° degree track to build a 360° circle of track. As we show you upcoming track plans... you'll see that having 30° and 45° pieces with the same radius is very important. If you're curious about how you'd build a circle using a track piece with a 13° radius (as 360° is not evenly divisible by 13°) we'll talk about this track piece in an upcoming article.

Straight Track, Special Track Sections And Turnouts
Feel like you're going around in circles with all this talk of curved track and radii? Don't worry, Micro-Track® comes in two lengths of straight track, 110mm and 220mm sections. Also there is a special 110mm feeder track section to get power to your track and my favorite... a 110mm uncoupling track for use with Micro-Trains® own Magne-Matic® couplers. This special track section allows you to couple and uncouple your cars automatically. In addition there is also a left and a right hand turnout in both a manual and a powered version.

We really just wanted to give you a brief overview of the Micro-Track® geometry and its origins in this article. We'll be looking at at basic track plans in future Z Scale Basics articles. If you have any questions or suggestions for what you'd like to see at Z Scale Basics, please let us know.