Adam walks through a simple solution to making pie cuts for your fabrication projects! www.fabco.uk ::::::::::::::::::::::::::::::::::::::: PIE CUT CALCULATOR bit.ly/piecutcalculator
You can use a length of angle iron to mark a straight line down a tube. Just lay the open side of the angle along the tube. It self centres because it sits on the 2 outer edges of the angle. Then align the edge of the angle with your centre line from using the tape.
Easier way to get the center line is use a piece of material that puts the sharpie at exactly 1/2 of the width of the pipe and just move all along the pipe.