Quickie Tool Intro

Okay, there is a Quality Assurance tool called an optical comparator.  They are usually really big and expensive.  I mean EXPEN$IVE.   Also known as a shadow graph.

Take a look, I'll wait right here.....

Optical Comparators   (Thanks, bitly.com!)

As I understand them, you place a calibrated transparent chart  on the thing, put your part on a stand (the focal length is exact, so the scale of the chart is accurate), then QA the geometry and/or dimensions of the part.  The part is magnified and the chart is superimposed. Too cool, and too big for me.

Then I ran across this guy:

The Tool and Die Guy

He introduced me to a nice bunch of tools, including...........

The pocket comparator:

Oh yeah!

I didn't even know I needed one before watching him!!  But this a most useful tool.  Need to check a radius?  No sweat!  How about an angle? Yup.  And it's got a ruler,  small circles, everything I could imagine needing.

A bit shadowy, but it's all there.

Ye olde radius gage.  Is it accurate??

Yes, it is what is says it is.  Perfect.

Meet the pocket comparator.  It allows me to be more precise when I grind tool bits, and check if I'm holding my tolerances like I should.  I am definitely impressed.  Now if I can find the instruction sheet that didn't come with it....