SCALED BODY

[sasha1]

USING NX6

I have a component where we are to machine a scaled version of the original solid body (0.9% of full size approx)to accomodate undesize forging.
Its a test machining process to establish best proactice.
We need to machine the scaled version and then a full size so I need to establish that by changing the scale percentages the changes cascade through to the MFG process.

The next step we take is to assosiative section through the body. I then create a sketch and offset the section curves (fully constrained) and name this component profile. We use this sketch to make stage sketches of the turning profile from the COS to the finished part.
we do this to make it easier to link the curves as a sketch for use within other assembled parts.
The problem Im finding is that if I change the scale of the body the Section curves update but the sketch doesnt. The sketch losses all of its constraints.
Any assistance would be much appreciated.



Currently using NX6

 

[jerry1423]

You may want to write all the expressions within the sketch so that they change with the scale, They won't change on their own.
For example:
p100=2.374*SCALE

 

[jerry1423]

. . . where "SCALE" is another expression
SCALE = 0.9

 

[sasha1]

The sketch is just an constrained offset from the section curves.
Any change to the model using synchonous modelling cascades to the sketch, but if I change the scale this doesnt update the sketch merely deletes the constraints that were in place prior to the change.

Currently using NX6

 

[jerry1423]

Oh OK.
The only way the sketch will update when scaled, is if it is located after the scale in the model tree.

 

[sasha1]

thanks Jerry,
The sketch is placed after the model is scaled
This is the order in the model tree.
1 Body
2 scale Body - enter scale percentage
3 Section curves - section curve thru the scaled body
4 Sketch - constrained offset from the section curves.


When i change the scale @2 the sketch at @4 doesnt update.
when you go into the sketch the offset constrain has been deleted.



Currently using NX6

 

[NXherbie]

Hi sasha1,
When you create the sketch @4, do you Project Curve (the Section Curves) into the sketch before attempting the Offset of the Projections?

It seems to work for me in NX7.5.

Regards,
NXHerbie
NX7.7/Tce2007

 

[sasha1]

Thanks for replies

Projecting the curve into the sketch work is such that it updates when the scale changes, however any subsequent sketch created referencing the sketch with the projected curves doesnt. Again they lose the constraints!
Of course the solution would be to reconstrain the sketch curves to the section curves, but I was hoping there way a way of it auto updating


Again thanks for the help

Currently using NX6

 

[mmauldin]

Have you tried to use Insert>Curve from Curves>Offset Curve to create your offset curves directly from your section curves instead of creating a sketch?