Well, the layout is rather simple. It is just an oval with 9 3/4th inch radius (19 1/2 inch diameter) at each end. That means (given the stated 21 inch width) that the straight tracks (of the oval) are set 3/4 of an inch in from each side.
So, take your 21" x 42" piece of plywood and draw a line 3/4" in from each of the 42" side.
Next, divide the 21" in half (10 1/2") and draw a centerline down the length of the board. On each end of this centerline mark 3/4" in from the 21" edges. Now it will be a simple matter of measuring in 9 3/4" in from these marks on the centerline to mark the centerpoint of your two curves. Use a large compass (or tramel) and draw a half circle on each end of the board connecting the two "straight" track sections you started off with.
Then you can use your actual track componets to work out the rest of the layout right on your board. Once you are satisifed with it, its time for the saber saw
George
"And the sons of Pullman porters and the sons of engineers ride their father's magic carpet made of steel..."
I fell in love with the N scale Great Northern but I have never folowed a track plan and have no idea how to graph this out to fit the board. I followed somones advice and tryed to blow it up but cant get it as big as they were wanting. If it helps I have a N scale track template 1:12 and when blown up as big as I can go at 145x it measures 5 scale feet by just about 10 by the foot scale on my template not sure any of this info helps but hope somone can lend a hand and get me going on this neat little plan..
Thanks Mike