I need some advice on how to set the curve radius ona 4 X 8 layout. I know I can only have a 22 inch radius curves, I also know I can use a yardstick to do this. The hole at the top of the yardstick is at the one inch mark, what I need to know is do I need to put the other hole at the 23" mark or the 22" mark. I know I sound like an idiot but I am extremely mathmatically illiterate. When I lay down the cork road bed do I center the road bed on the line I draw. I know this is a dumb question but I am an idiot with measurements.
If you truly have a hole at the one inch mark, then you would need the hole you want to set your arc at one inch plus the 22 inches you need for your radius. One plus twenty-two equals twenty-three…your answer.
Building a layout can be a very complicated endeavor, pulling on lots of skill sets - perhaps more than any other hobby of which I am aware.
While some of us may have the basics down in all those skills, few of us are experts in many of them. And if we are, we didn’t get there overnight. Experience/practice are the cornerstones, but even with that there are some skills that some of us just can’t capture.
The fact that you are attempting to build a layout, AND have the “moxie” to ask questions (even if you think they are dumb) says a lot.
We (well, most of us anyway) are here to help one another!
Let’s make a few assumptions here. Your track plan is a loop for continuous running, and you want the broadest possible curve that will make a 180 degree turn without falling off the edge of the table? You will have an oval, with straight sides running down the length (the 8 ft length) of the table?
Step one is to locate those straight sides of the oval. Most of us want the track set back from the table edge by a little bit. Just how much is an esthetic decision, you want enough to look good. Once you have the straight sides located, measure the distance from one side to the other. Measure from centerline to centerline (look for the nail holes in the ties). That is the diameter of your curve. Divide diameter in half to get the radius. Radius ought to come out close to, but not exactly, 22 inches.
You want to swing your arc from halfway between the two straight tracks. This will be close to, but not exactly on, the centerline of the 4 * 8 table. Draw a pencil line down the halfway place. Swing your yardstick compass (trammel) from a spot on the halfway line that brings the track close to, but not falling off, the edge of the table.