How to convert inches to degrees - Inspecting the perpendicularity of 2 lines

F

fabiolag

I am inspecting the perpendicularity of 2 lines with a GD&T tolerance of .001". If I am using a vision system to trace the 2 lines and taking the angles between them (the angles have to be around 90 degrees of course), how do I know how much tolerance I have in the angle measurement in terms of degrees? In other words, How do I convert .001" to degrees?

I did the simple conversion equation of:
1/1000 = x/360
and got x = .36; so that means my angle can be between 89.64/90.36 degrees

But I am not sure if it's that easy.

A

Atom_Ant

If you want to calculate the positional deviation from nominal based on the angle, it depends very much on the length of the lines. For example, if you are 1 degree off of nominal, your line will be out of position by .017" for each inch of distance.

Randy

Super Moderator
There are 6400 mils in a circle (1 mil = 0.05625 degrees and 1 degree = 17.777777778 mils)

At 1000m a mil = 1 meter (at 1000m from center a circle has a circumference of approximately 6400m)

At 500m a mil = 0.5m

Start coming back from there to the measurement you have and convert meters into inches