I'm not sure y'all get what I'm saying. You bend out a 90* piece of tube out of the die set first. Before you bend it, you make a mark on the tube right at the leading edge of the die. Then bend the tube 90*. Once it's bent 90* pull it from the bender dies. Look at the area where your leading edge mark was made. Now start looking toward the inside radius of the very first area of the tube that actually starts to bend. It is always back set from the leading edge of the die roughly 1/8" or so. This is where you grind a notch in the die so you know where your actual start of bend is at.
May not sound like much but multiplie bends or compound bends this makes a huge difference. At least for me it does anyway.