Construction help

[jimmcw]

I am trying to take a measurement from the apex of a constructed 100 degree cone tangent to a measured sphere. I'll attach an image to give an idea of what I'm tryin g to do. Can this be done in PC-DMIS? Capture 6-365.PNG

[gibsonridge]

have you tried constructing the Gage diameter on the sphere tangent points? then report distance to the apex point. or is that not what your looking for?

[Rich P]

measure a conical feature and a plane, you can offset plane to intersect cone and evaluate diameter at that location. do this on a conical feature that defines the size at a gage point to define size at a specified location.

[jimmcw]

I am trying to measure the "10.744" dimension in the picture above. The blue lines are constructed and are not measurable features.

Thanks

[UKCMM]

If you have already constructed the cone then to get the vertex point construct a circle from the cone with a zero diameter this will give the vertex point position.

[UKCMM]

It is not clear what the problem is, is it the construction of the feature or the dimensioning.

[Mike Ruff]

I would recommend doing this using several 2D evaluations. You can take a line on each side of your cone and then click Insert> Feature> Constructed> Circle. From the dropdown select "Tangent 2 Lines". Key in your gage ball diameter and dimension the circle to the cone vertex, add radius. I would also recommend doing this at a minimum in both X and Y workplanes

[JEFMAN]

You can do it by a little trig, from the sphere center (If the cone is aligned on the sphere center, it's a 2D problem between a line and a circle).
So the line is at 50° (half angle), so the radial line is at 50°.
The contact point between the line and the circle is Rcos 50 on X and R sin 50 on Z.
Then the cone vertex is (5cos50)*tan(40) + 5sin 50 on Z from the sphere center.
trigo.JPG

[jimmcw]

This is what I was looking for. Thanks!

[JEFMAN]

ASSIGN/V1=5*(COS(DEG2RAD(50))*TAN(DEG2RAD(40))+SIN(DEG2RA D(50)))
ASSIGN/V2=MPOINT(SPH1.X,SPH1.Y,SPH1.Z+V1)
Then create a generic point with V2.X,V2.Y and V2.Z