Here ye be Harry, You wrote: > Clark Lord once had some diagrams and formulae for laying out entry and >exit curves. Clark . . . you awake?<<
Clark wrote a formulae in Oct 2000: I remember everything Clark ever wrote and every time he didn't buy me a beer! Secretary Geoff. Here it is: First you mark your track boards with the curve. Include transition curves going in and coming out. A simple long (8 to 10 feet) flexible straight edge will automatically make the transition curve. I use a piece of 1/8 thick x 1/1/2 wide pine furring batten. By clamping one end of the flexible piece to the straight rail and pulling the loose end over to the curve section the resulting line is the transition curve. The way I get smooth curves is to offset one rail joint from the other. For instance when I approach a long curve section I stop laying straight track and just cut the inner rail in half. This way the outside rail is say 6' long and the inside rail is 3' long. You then pre curve the needed number of rails. You slide a pre curved 6' long rail into the tie strips on the short side. Now the outside rail is the short side so you slide a 6' rail into the tie strips on the outside which makes the inside the short side. Back and forth adding tie strips as needed and making single rail joints where ever they occur. Don't worry about rail length until you get to the next place where even ends are needed, like a turnout. Then you can cut both ends even and install the turnout. On the other side of the turnout again put down a long and short rail and begin the process all over. I know it is a bit fiddly but with a ~3' stagger in rail joints the curve will be very smooth as it goes around. Also straight track won't kink at the joints because the long rail supports the joint on the short rail. Clear as mud you say. Try it, you'll like the results. Clark
