Need help reporting Taper/foot of a Cone

That just didn't occur to me.  What an elegant solution!  I have known for a while that PC-DMIS can construct a circle on a cone at a fixed distance away from its vertex, but I never encountered a situation that would use it.  Now I know a good one.  

All due respect, I'm not trying to be a critic, I appreciate all the help. And I'm new to this so I don't know how to do everything.

When I think thru the steps to do it this way, I would have to have some way of finding the cone apex on every part. I could make a point at the theoretical apex if the cone was exactly to print, but if its not the exact right taper angle or the start and end diameters are not at nominal the cone will have a different apex and a different location for the constructed circle. I don't know how I could make the apex point and constructed circle move depending on the measured angle and location of the cone. But if there is a way to do that then I think this method would be superior to the key-in dimension way I'm using now.

With that measured cone value you have right now, go and create a constructed circle, and in the dropdown menu select Cone, then select Type of Height and put in 12 and leave it on the option of Cone Vertex. See what the diameter is of that circle. 

WilliamL beat me to it.  As he said, it is built right into the circle construction.

Awesome, I will give this a try

There's a ton of theoretical methods to extrapolate "A" result that aligns with the drawing. 
--But again, no matter how you create this theoretical method, it's going to compound the measured uncertainty  
You have an axis line that's <1.5" long (I'm guesstimating from print scale the length of your actual axis line), and you want it judged from a theoretical intersect diameter at 12" away...  12/1.5" = 8 
Any time you take your measured result and judge it from 8x away, you are also measuring with uncertainty multiplied by that same value.

If you want an accurate result, you'd to have judge the actual cone as it's measured, with your tolerance relative to your actual metal part's prescribed limits based on the theoretical taper..
So, because i'm not a math genius, I open autocad, and draw my 2d cone nominal: 1.5" diameter at 12" in length. 
Then i draw the UTL 1.51" at 12" in length.
Repeat for LTL 1.490" at 12" in length.
Fit my part at that .8125" REF diameter. 
Then I'd affirm the actual tolerance limits (EX: diameter at interval cuts etc), to understand my actual tolerance limits of the cut steel, without projecting any axis or measured value.

Bestfit align (offset with that basic apex zero point relative to the ref 0.8125 diameter) then output the results relative to what i decided were representative tolerances from autocad.

Print out autocad math, print out results, and document whatever you need to justify the results to be exact black and white PASS/FAIL, and by how much material is still safe on the steel, or by how much material has been overcut.  Something that a machinist can actually use to understand the problem with his setup.

That is the method I prefer for these types of "well we think its good" measurements. Draw it out in SolidWorks, draw the actual tolerances, as long as the CMM tells me I'm within the "box created by the little lines of the cad" then we can confidently defend our measurements if anyone asks. 

Works great guys thank you

I'm probably not understanding this, but when it comes to the uncertainty, I am getting a repeatable measurement. Checking the parts over and over again the taper is coming out to between 1.527-.1.531. I also have a "good" part from the last run that is consistently around 1.510-1.514. I appreciate the message and will revisit this another day and what you are saying will likely dawn on me then. I learn after the fact