distance between a line and circle

[Carolyn McKean]

When dimensioning the distance between a line and a circle I am getting 2 different answers. If I do line to circle it is 6.2 mm longer than if I do circle to line. When I first programmed it I did line to circle and the dimension was out of tolerance so I went to engineering thinking I had a bad cad file. They checked out the cad file and said it was good so I started playing around with my program, trying different things when I came across this situation. Why would it matter what feature I choose first if everything else is the same??? Has anyone else seen this before?

[kmcmm]

can you post a screen dump of your graphics display window?

[Matthew D. Hoedeman]

When you do LINE to CIRCLE, it uses the CENTER point of the line to the center point of the circle, when you do CIRCLE to LINE, it does the shortest distance, circle, perp to line, not to line center.

[Tested]

Are you checking them to a axis or to one another?

[Carolyn McKean]

I tried several things. I rotated to the line and set the 0,0 in the circle, and still get 2 different answers. I did a distance between the 2 and also did location of line. Location was good and so was distance if I did circle first.
My opinion is they should calculate them the same no matter what order you use.

[Matthew D. Hoedeman]

I tried several things. I rotated to the line and set the 0,0 in the circle, and still get 2 different answers. I did a distance between the 2 and also did location of line. Location was good and so was distance if I did circle first.
My opinion is they should calculate them the same no matter what order you use.

BUT, when you select the line first, Pcdmis ONLY 'knows' a few things about it, really, the ends, the middle (which is what it reports for LINE LOCATION) and it's vector. So, when you select LINE first, it has to make assumptions, and it assumes that the center is what you want (what it reports for LOCATION) to start from.

[Roberto]

When dimensioning the distance between a line and a circle I am getting 2 different answers. If I do line to circle it is 6.2 mm longer than if I do circle to line. When I first programmed it I did line to circle and the dimension was out of tolerance so I went to engineering thinking I had a bad cad file. They checked out the cad file and said it was good so I started playing around with my program, trying different things when I came across this situation. Why would it matter what feature I choose first if everything else is the same??? Has anyone else seen this before?

Just curiuos, when you recall distance between the two features. What distance type 2D or 3D? That'll give you different results.
Good day!!

[AuRules]

Is this example what you talking about Matt. Since I sitting hear waiting on the operators to fire the machine up and give me some work.

[Matthew D. Hoedeman]

Is this example what you talking about Matt. Since I sitting hear waiting on the operators to fire the machine up and give me some work.

Yep, that is what it does.

[RussL]

Catia does similar things with measure.

I believe the software should be written to re-evaluate the first element once the second element is chosen so you get the same answer regardless of order.

[cmmguy]

Catia does similar things with measure.

I believe the software should be written to re-evaluate the first element once the second element is chosen so you get the same answer regardless of order.

Exactly. Otherwise is stupid.