Deviation perp to centerline

[phil george]

Does anyone know the math behind the position calulation with this option turned on? I have a customer that wants to use it since it makes the postion significantly better - but they need to be able to justify/explain it to their customer and I don't know what's going on there. Clearly it's not just the square root of the the sums, etc.

[Matthew D. Hoedeman]

What it does is it 'constructs' a plane, perpendicular to the nominal VECTOR line of the feature being measured, through the actual measured feature, then calculates from the actual measured position to the intersection of the nominal vector line and the constructed plane. This gives the position of the feature to nominals, but 'compensates' for the deviation of the surface and leaves it out of the calculation. It is pretty much a 'required' option for checking the position of holes in sheet metal where the surface is not square to body line (vectors of 0,0,1 or 0,0,-1 or 1,0,0 or -1,0,0 or 0,1,0 or 0,-1,0). It simulates the use of a stab pin to check the hole.

[phil george]

I get it. Looks like I won't be able to use it this time, but thanks.

[ag1979]

This took a long time to get right

This is to calculate 2D true position (TP based error perpendicular to the centerline).

[phil george]

Thanks for the hard work.