Hi,
This is how I bend a rolling offset. How do you do it?

First I measure the vertical distance I need center to center, then the horizontal distance I need center to center.

Then I lay this out on the floor using a pencil or chalk making two perpendicular lines.

I start by making a right angle that is exactly the same measurement as the vertical and horizontal center to center measurements taken first.

Once this is done, I will simply measure the distance between the end points of each perpendicular line. This measurement is the depth of offset to land the pipe in perfectly. This is especially helpful when you need to hit a knockout.

I am sure there are other ways.

-regards

Mustang