"great! thats what im talking about...
how do I fix the distances for BB and rear axle?"

Do you mean, how do you design a bike? Or given that you have one you are copying already, how do you get that on your frame jig?

The former is a big subject. The latter, is just a mater of measuring the BB center down from a line drawn through both axles (tension a string), then measuring the rear hub distance from the BB center. With those two numbers you can measure the bb position down from the wheel center line on your jig, and use a compass from the center of the BB and the point it crosses on the CL to establish rear hub position.

You mentioned something about a single speed, so if you have a bike whose design you currently like, but want to make in bamboo, just use a compass and an inclinometer. Draw your BB, relative to your axle height. Then shoot a line up at the angle you want your seat tube to be. Get the angle and length from your model bike. Then measure from the center of the BB and the center of the seat tube top end, to the center of the lower end of your head tube. Measure the angle of the head tube. Along with the rear axle is all the info you really need. The precise position of every tube varies depending on how you are joining it, some methods need more space than others. But those angles and relative positions establish the bike's geometry.