Intersection Point

[#2#]

Morning All,
I hate it when I start the morning with questions...
I have a part where a dimension is from the point where a line and a radius intersect. The dimension is not perpendicular to the line. I know how to create a pierce point to get that point from a circle and a line. The problem I am having is that PC-DMIS says the line doesn't intersect the circle. Any suggestions/workarounds? All I can think of is to measure the circle through more degrees of arc. The problem is that will screw up the radius of the circle and shift the point a little.

I will work on posting a drawing.

[craiger_ny]

Can you construct a generic circle on the radius using the radii's dimensions then intersect the line into the generic circle?

Craig

[Bill **********]

I've seen this when the two features aren't on the same plane. You may need to construct a plane and project the features to that plane before they will intersect.

Bill

[#2#]

Can you construct a generic circle on the radius using the radii's dimensions then intersect the line into the generic circle?

Craig

I'm not exactly sure what you mean. Here is a drawing. I am looking for the 2.60 dimesion labeled 98.

[Mark Farren]

Check the vector direction of your line, I 've had that deal me a fit b4. You may need to reverse it.

[craiger_ny]

Location > add radius? oops I just got the part about the line not being perp, can't do that. I'll have to think a bit.

[Mark Farren]

or possibly a 3D line and construct a pierce point....

[bboyd]

Can you not rotate the 1.173 degree's to get that DIM?
A quick fix maybe to trig out the difference to make a ref dim that is perpendicular

[#2#]

Can you not rotate the 1.173 degree's to get that DIM?
A quick fix maybe to trig out the difference to make a ref dim that is perpendicular

The 1.173 is a dimesion plus 1º draft angle (casting). I can rotate to the side of the part but then I am having trouble finding the point to which the bottom leader line points.

I think I am not going to worry too much about it. That detail is for a power switch. Flexible wires going in and out so it shouldn't be too critical.

[Cumofo]

is anybody listenig?

I've seen this when the two features aren't on the same plane. You may need to construct a plane and project the features to that plane before they will intersect.

Bill

welll?

[#2#]

I talked to the QE - he said don't worry about it we don't need that dim. anyway.

Well, why the helk didn't you tell me that to begin with so I wouldn't have wasted time trying to measure it!

[Mike N.]

I've seen this when the two features aren't on the same plane. You may need to construct a plane and project the features to that plane before they will intersect.

Bill

right on brother

[george frick]

i have had this problem b4. it seems that pcdmis will not calculate a point when the elements are tangent. i've got a message that says: "math does not converge". had to check the feature on the zeiss with umess300 software. the algorithms are not there in pcdmis. what a shame.

[cmmguy]

I know that you solved the problem without actually solving the problem. Actually sometimes when they say "Oh don't bother checking that dimension", you breath a sign of relief. But your question still begs for an answer.

It is very possible that the line and radius(or diameter) will never intersect because the line "zooms" past the outside of the radius, ie the radius is too small. But one way to get that is as follows:

Construct midpoint between that radius and the line, then construct line between the arc and that midpoint, then construct intersection of that line and original line and then the point of intersection is the desired point. Maybe you could simply "cast" the point onto the line and get the same result. NOTE: The radius and line would need to be on the same plane.

[IMG]http://www.*******.com/misc/pcdmis/lineradius.jpg[/IMG]

[george frick]

I know that you solved the problem without actually solving the problem. Actually sometimes when they say "Oh don't bother checking that dimension", you breath a sign of relief. But your question still begs for an answer.

It is very possible that the line and radius(or diameter) will never intersect because the line "zooms" past the outside of the radius, ie the radius is too small. But one way to get that is as follows:

Construct midpoint between that radius and the line, then construct line between the line and that midpoint, then construct intersection of that line and original line and then the point of intersection is the desired point. Maybe you could simply "cast" the point onto the line and get the same result. NOTE: The radius and line would need to be on the same plane.

[IMG]http://www.*******.com/misc/pcdmis/lineradius.jpg[/IMG]

excellent example cmmguy. this condition will also give you the "math does not converge" message, but in this case it's a true ststement. a "bump" to you!