Saturday, June 02, 2007

XtrkCad Tutorial Part 4: Curved Flexitrack

We’ve nearly finished our tour of XTrkCads features, but the last thing to mention is also the most powerful: Curved felexible track.

XTrkCad offers no less than four methods of creating curves. I’ve described them all below, but you’ll probably find one or two that you prefer and stick to them. Don’t worry too much about making your curves perfect first time. Later I’ll show you how to edit them, a technique which is useful for fine tuning them.

The Create Curve button is on the button bar to the right of the Create Straight button. The icon changes to represent which of the four methods is currently selected. To change the method, click the down arrow to the right of the button and select from the list. As with the Create Straight button, click the Create Curve button to select it.

Create Curved Track From End-Point: Click on the track end from which you want to start, and drag the mouse as though you where continuing in a straight line as shown.

Release the mouse and two red arrows will appear at the end point. Click and drag on the arrows to adjust the length and angle of the curve. Release the mouse to fix the curve.

Create Curved Track From Tangent: Click on the track end point and drag the mouse at a right angle to it.

The distance of the mouse from the track represents the radius of the curve you are creating. Release the mouse and you will see a line with two red arrows. Click and drag the red arrows to adjust the length of the track.

Create Curved Track From Center: This is effectively the opposite of the previous method. Click and drag from the centre point of the curve to where you want the end to be. Release the mouse.

Click on the red arrows, and drag to adjust the length of the curve. This method would be useful for, for example, creating curves at the end of the baseboard from the front of the layout to a hidden siding behind. Just use the midpoint of the baseboard as the starting point.

Create Curved Track From Chord: Click on an end point, drag to were you want the other end point and release the mouse.

Two arrows are shown in the centre of the track, click on them and drag to adjust the angle of the curve.

Once the curve is created you can join it to neighbouring tracks using Connect Two Tracks as we did in part one.

Editing Curves

Now that you have created your curves you may find that they need a bit of ‘nudging’ into position.

This can be done it one of two ways. The first is to select the Modify button , then click an endpoint and drag it around.

The other is to click on the curve to bring up the ‘Describe Curve’ window. If neither end of the curve isconnected to another track, you will have options at the bottom to select the Pivot - which point will remain fixed. If one end is connected, the pivot will be at that end. (If both ends are connected you can’t edit the curve - you will have to break one or both of the connections first).

Most of the options in the window are fairly obvious. There are options to adjust the position and radius. If the track has an Angular length of 90 degrees, then it is a 90 degree bend, 45 degrees is a 45 degree bend and so on. I’ll admit to having no idea what the CW and CCW options do. Their behaviour seems non obvious and I can’t find anything about them in the documentation. As far as I can tell they relate to creating easements.

You can also make adjustments using the mouse as shown previously for straight track. Select the track, right click and choose Modify, then click and drag to adjust the radius and length.

Parallel Tracks

A useful feature for creating double track lines, as well as parallel lines in stations and sidings is Create a Parallel Track. With it selected click beside an existing track section and a parallel piece of flexitrack will be created to that side of it.

To create a longer length of parallel track,just keep alternernately clicking the parallel track button and next to a piece of flexible track. The new tracks will be automatically joined together.

Note however, that you can only create parallel tracks next to pieces of flexible track, but you can use ‘join tracks’ to link section together.

Here’s an example of how to use it too create a passing loop. Start with two turnouts, connected by a piece of straight track.

Select Create a Parallel Track and click just below the straight track.

The new track will be the same length at the original, and impossible to connect the them so we need to shorten it.

Click Select and click the new parallel piece of track to turn it red. Right click on the track and select Modify. Now click on one end and drag it shorter such that a curve to the turnout will fit in nicely. Repeat this for the other end.

Now to join the track to the points. Select Join Two Tracks, click on one end of the new track. Click and hold on the neighbouring turnout and drag the mouse until the joining track shows black. Again repeat this for the other end.

This technique can obviously be used for sidings by just connecting one end.

Summary

I’ve now covered just about all the basic track laying and editing features. There are a couple of advanced features which I haven’t had time to cover. These include:

  • Easements (also called transition curves). Use these to create gentle lead ins to curves, as used on the real railways.
  • Layers. You can use layers to divide your layout into separate sections. XtrkCad can then hide or show individual layers. This is particularly useful for layouts with gradients and multiple levels.
  • Gradients and levels. This feature is pretty much self explanatory. Use it where, for example, one track passes over another.
  • Run Trains. XTrkCad includes the option to add locomotives and cars to the layout and run them as if you where using a physical layout. You can use this to test out the design, or simply as a way to ‘play trains’ without having to build a real layout.