I don't have any drawings with measurements, and while I think one could build one if so desired, it may be much cheaper and easier to buy one. With the price of tubing these days, I think you will spend more than just buying. Frames are the easiest part of a simplex to find, they can be had for a couple hundred dollars. Now other parts, such as motors and gas tanks are much harder to locate in good condition! Good luck and keep us posted! Rick