How to measure the True Position on an Optical Comparator

[jesterjay8]

Is it possible to check the true position on an optical comparator? I have a callout for TP on the ID of drilled out bolt. Basically, cylinder, head, with a drilled center. Hopefully I'm describing this accurately enough to be understood. :/ But if anyone knows can u break it down for me please? I know what the formula is, just don't know how to get the numbers to plug into it.

Thanku!!

 

[Jim Wynne]

Re: How to measure the True Position

Is it possible to check the true position on an optical comparator? I have a callout for TP on the ID of drilled out bolt. Basically, cylinder, head, with a drilled center. Hopefully I'm describing this accurately enough to be understood. :/ But if anyone knows can u break it down for me please? I know what the formula is, just don't know how to get the numbers to plug into it.

Thanku!!

Without seeing the drawing, what's intended is probably coaxiality of the drilled hole with some other feature, perhaps the head of the bolt. The two features should be sharing a centerline, in other words. This can be measured on a comparator, so long as the part is properly squared to the lens, just by finding the centers of both features and the distance between them. This assumes a comparator with a digital readout (DRO). If you find and store the center of feature "A" and do the same with feature "B", you can then have the DRO give you the distance between the two, which will be the same straight-line distance you would get if you measured in the x and y axes and then calculated the position.

 

[jesterjay8]

Re: How to measure the True Position

This helps a lot, thank you!!