Measurement

[Slaen]

I have a line that is at 7.5 Degrees from the x axis. But when measured it shows as 7.499 degrees.

Any Idea why this would happen?

 

[CPosner]

I think it is a bug in Catia. What release? I'm on 17. I have had the same thing happen to me with some measurements. When I go back to the definition the parameter is x.5, but measurement says x.4999999

 

[Slaen]

R17 as well.

I tried messing with the trailing zeros. Unfortunatly I dont think this fixes the problem I think it just hides it.

 

[catiajim]

What service pack? I think there was an early bug (SP3 or so) that caused this. Should be fixed in higher level SP's.

 

[Cosirius]

Its a bug, i have the same problem, but when i use drawing i use fake if i need x.0001 tolerance.

With kind regards,
Cosirius.

 

[DBezaire]

Slaen - I tried R17 SP6 on a 32bit - measures 7.5 deg

Regards,
Derek

 

[jackk]

I always thought it was just a poor job of rounding off when all the 99999's show up in measurements.

Cosirius: are you getting the 4.4999 even when you use the .0001 precision?

 

[Cosirius]

Yes, jackk. But i work with 2 decimals max so i dont get this problem very often

With kind regards,
Cosirius.

 

[1oldcaduser]

Does anybody know of a manufacturing process that can produce something accurate to 5 decimal places(either mm or inches) 2 decimal places is good enough for 99% of processes so why worry about it

 

[catiajim]

Actually, I do know of a process that requires that kind of accuracy - Optics. There you are talking about angstroms.

On a practical level - many aerospace components and mechanisms require +/- .0005 tolerances. Not many, but a few. Otherwise, +/- .010 is pretty typical for engineering tolerances, which means the tooling tolerance is .003

But those are linear tolerances, not angular.

I still think you are dealing with a bug that is fixed in a higher SP. We are running R17SP5 without this problem.