offset question

[PoorOwner]

When using calculator for bending offsets, do you measure from the wall to the edge of the KO circle, or to the middle of the circle?

When I bend the second bend it usually unbend the first part of the bend, not sure what is the best angle to use?
In this case, my KO is about 1.75" away from wall and I only have about 20" of vertical to work with, maybe even less if I count the LB length.. what angle is good to go with?

 

[Bert_]

Usually measure from back of pipe to back of pipe. 30*'s are good because the math is easy, multiply distance by two for your marks.

For tiny box offsets like you are doing I just guestimate. It's easier.

 

[Mr. T]

You are offsetting from the center of where your conduit is running to the center of where your conduit will be running.

Like Bert said, for a little box offset you have some room to fudge it. I’d say the center to center thing would be more important for something like an eccentric knockout or when trying to offset something structural.

 

[dscheidt]

You are offsetting from the center of where your conduit is running to the center of where your conduit will be running.

Like Bert said, for a little box offset you have some room to fudge it. I’d say the center to center thing would be more important for something like an eccentric knockout or when trying to offset something structural.

Center to center is the same as bottom of conduit to bottom of conduit, assuming you have normal conduit of constant diameter. Bottom to bottom is usually easier to measure, because you measure from the wall.

For 1.75, I'd use a a 22.5 offset, 4 9/16 between marks.