Tolerance in features in NX8.5

[IEngr]

hi,
Can someone explain the reason behind providing tolerance in the feature. For better understanding of my question , I have added a snap of it.
How it is helpful, its uses ... etc..


Thanks,
Isha

 

[ranjithbelur]

In CAD tools, tolerance(distance and angle) is the freedom for it to create any features. For example, if you want to sew two sheet bodies, even if the sheets edges have some gap, still they will be combined if the distance between the edges of two bodies is less than the tolerance specified. Same way for other features. this is the general explanation i hope. Maybe someone can explain it in depth.

 

[Xwheelguy]

It's there due to the need for approximation when necessary. It's not always going to be used, only when the software needs to use it.

In addition to the above, it's generally encouraged practice to "set it and forget it". In other words, try NOT to change the tolerance value on a feature basis - set it in your Modeling Preferences and leave it alone. Will it be the end of the world if you don't do this? Probably not, but you might risk downstream issues if you run into some odd models here and there. For me, I don't want to waste my time remodeling something due to going against the advice of seasoned users, so I tend to set it and leave it alone. A former Siemens employee suggested using 10% of the smallest manufacturing tolerance as my modeling distance tolerance. Angle tolerance, probably start with the default 0.5 and once you feel more comfortable with your modeling you can decrease it by half if you wish - but if you're not doing much Freeform Modeling, you won't have a real need to mess with the Angle Tolerance.

If you have issues with your chosen tolerance, then it might be worth looking into increasing your chosen setting OR go back and try to improve your modeling technique - start with the curves being used.

Tim Flater
NX Designer
NX 9.0.3.4 Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB

 

[IEngr]

Thank you Tim n ranjith