chordal deviation

[Duckman]

when I use modify->break->spline to arcs,

 

what does the geometrical quantity does the error, chordal deviation represent?

[Greg McKay]

According to Mastercams award winning help.

 

Sets the chord height tolerance, which is the maximum distance the reulting arc and line segmentscan vary from the selected splines. A smaller value results in a closer fit between the arc and line segments and the original splines. A larger value results in a looser fit.

 

I suspect you are having a problem with break spline.

 

What is the problem?

[Duckman]

yes...i am using the function to essentially break a spline that is very close to a complete circle...when I bbreak the spline, with chord dev of 1, the resulting arcs all have the same diameter and center point to within .000001. Conceptually, I am thinking that all these arcs should be merged into one big arc, but it doesn't seem to be happening...any ideas why?

 

THanks!

[Allan]

Perhaps you want to use the convert splines to arc command. The break splines to arcs command has a look ahead and i think that is where the problem is.

 

Allan

[Duckman]

works like a charm! thanks allan!

[cadcam]

I usually use what Allan said. But it does not always change all splines to an arc so some times you need to use this other tool or create point Dynamic to use a spline breaking point then create a arc from this info.

 

Just a few thoughts on this

Or should I say my thought on this.

[Duckman]

any ideas under what circumstances it won't work?

[cadcam]

None leaner planes is one.