used this building Go karts. It simple to use. Just fill in the blanks and hit print. cut along lines and wrap it around your tube. Mark with pen and start grinding. Saves me lots of time with clean look.
Thought I would pass this on here. It's a cheap way to get fast clean notching. Simple as well. Change the angle and tube size and you will see how it works. You get some crazy shapes but when wraped on the tube you get the perfect notch. I used this before and it is spot on.
http://metalgeek.com/static/cope.pcgi" .".." ."..
Description
This is a reconstruction and expansion of Eric Fahlgren's clever "miter" program written in 1994 to help in building bicycle frames.
Some Explanation
In case it's not entirely obvious, the point of this thing is to create a cutting pattern for a tube or a pipe to accurately fit it at an angle to another tube or pipe so that you can weld or braze it. This is a whole lot easier than eyeballing the cut and scribing it by hand, and if you do it right, both the grinding and welding are pretty easy. This process is also frequently called "tube notching" or "pipe notching". Apparently, this script/form/PHP widget has become popular with a number of hot-rod, off-road, and vehicle modding freaks engineers.
It really is slick.... A few practice runs and it's a simple as can be. It's free as well. Pics are many words so here you go.