how to measure shoulder angle?

[JeffG]

Hello,
Thanks for having the patience to help a newb. I'm trying to calculate the shoulder angle from a wildcat reamer. I tried simple trigonometry of measuring the diameters and lengths to the shoulder and neck, but that didn't seem to work when checking a known shoulder angle.

Thanks for the help,
Jeff G

 

[rijndael]

Just thinking out loud ...

If you have the diameter at the case shoulder junction, the neck diameter, and the length of the shoulder, can't you calculate it as if it were a trapezoid?

(Delete the default "givens" and put in your segment lengths)

Trapezoids Calculator - find segments, given midsegment

Trapezoids Calculator - find segments, given midsegment

www.symbolab.com

Or, maybe their Geometry calculator and do it via parallel lines?

 

[Edd]

Hello,
Thanks for having the patience to help a newb. I'm trying to calculate the shoulder angle from a wildcat reamer. I tried simple trigonometry of measuring the diameters and lengths to the shoulder and neck, but that didn't seem to work when checking a known shoulder angle.

Thanks for the help,
Jeff G

Post your measurements.

 

[JeffG]

I realized my mistake!

I was taking the difference between the shoulder diameter and the neck diameter as my "B" tangent number.

I should have been using HALF-diameter differences.

Thanks for walking me back...