Drawing a Curved Turnout

Some TrackLayer users have been asking how to draw a curved turnout, like this one:

This document describes the procedure we use.

Choose the Guide Circle tool  and draw a big circle overlaying the inner curve of the turnout.

As you probably discovered if you've tried it, the way to draw a big circle is to do a series of short drags in opposite directions.  In this example, position the cursor near the bottom, press the mouse button, and drag upwards towards the curve.  Then, without releasing the mouse button, press Shift, drag downwards, release Shift, drag upwards, and repeat until you get the radius you want.

This shows the circle in position, overlaying the centerline of the track. 
 

If you don't get it right on the initial drag, you can adjust.  Use the Edit Track tool  , click the circle to select it (it turns navy blue), then press a point on the circle and drag.  In this case, Shift ON adjusts radius, OFF adjusts position, opposite the behavior when creating a new circle.  It makes sense if you try it.

Use the Straight Track tool    to draw a tangent at one end of the curve.  Position the cursor on the circle so it highlights in green, then press and drag.

Draw a second tangent on the other end of the curve.

When you release the mouse button, the circle disappears and the curve becomes track.

Using the Circle tool again, draw a circle overlaying the outer track.

Using the Straight Track tool, draw the tangent on the Y end (the right end, in this example).

Now the tricky part.  For the following steps you might want to turn off the background image and zoom in close. 

Draw the tangent on the left to complete the outer curve.  Don't worry too much about where you drop the endpoint.  As you'll notice, you cannot drag to any point inside the blue circle, so you can't create the switch in this step.

Release the mouse button.  You lose the circle and get the outer curve.

Using the Edit Track tool, position on the endpoint of the tangent you just created, press and drag.  Adjust the position of this endpoint so it falls just short of where you want the switch (i.e., it needs to be on the "Y end of the frog").  You don't have complete freedom of movement, because the program insists on keeping the dragged section tangent to the circle.

Using the Straight Track tool, add a little segment to connect the outer curve to the inner.

When you release the mouse button, you get the switch.

At this point you might be tempted to use the Edit tool to make some tiny adjustments.  It's not advised.  When you try to drag a multi-connected point on or near a curve, tangency rules and things fly out of whack.  Be prepared to Undo.

The finished turnout:

A thing of beauty and smooth functionality. [ Or not.  This diagram was damaged and hastily modified so the two diagrams don't match, but you get the idea. ]