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overconstraining in sketch

Valued Contributor
Valued Contributor

In the example below, I have a curve and a short line at first.

 

Then I create a sketch:

  • on the plane defined by the short line and Z axis,
  • with the line end as the origin.

In the sketch:

  • The outside curve is projected to give the grey reference curve.
  • A spline is created, starting from the reference curve.
  • Pole No.3 is constrained on axis X.

ODD: Either action below would lead to overconstraining:

  • drag the free pole No.2 arbitrarily
  • constrain the free pole No.2 on axis X

Help would be appreciated!

---------------------------------------------------------

At first I have a curve and a short line.

Image.png

 

I create a sketch, project a curve, and create a spline in it.

Image.png

 

Pole No.3 is constrained on axis X.

Image.png

 

drag the free pole No.2 arbitrarily

Image.png

 

constrain the free pole No.2 on axis X

Image.png

5 REPLIES

Re: overconstraining in sketch

Legend
Legend

I don't know much about splines, but it seems to me I have better luck in your case if I

(1) Double-click to edit the spline, then move the poles. Editing this way seems to delete a constraint instead of creating conflicting constraints.

(2) Edit the spline and add one more pole. (five instead of four.) Then there is one pole with freedom between Pole(2) and Pole(n-1). In this case, pole(2) and pole(4) are constrained along a line to create the G1 tangency at the ends. Then I can drag the poles to shape the spline.

 

It seems like you basically need one more pole in the spline to give the freedom to make any change to what you started with.

Re: overconstraining in sketch

Legend
Legend

Hi @surfactant

 

Actually, the G1 Continuity is not same with Sketch Tangent constraint.

The G1 Continuity including Magnitude value besides tangent constraint.

 

Please try to use  Sketch Tangent constraint instead to G1 Continuity.

 

 Sunkap Ahn, Senior Support Engineer


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Re: overconstraining in sketch

Valued Contributor
Valued Contributor

Hi @MarkLawry @SKAHN   Thanks for your replies!

 

If the projected curve (grey reference) is replaced with a curve created in the sektch, the issue is gone.

 

Image.png

Re: overconstraining in sketch

Siemens Phenom Siemens Phenom
Siemens Phenom

Just for info...

I could reproduce this in an old NX versions, but starting NX 12.0.1 this problem will not occur anymore. 

 

Regards, **bleep**

Re: overconstraining in sketch

Valued Contributor
Valued Contributor

Hi @DickBaardse   OK. Thanks for checking!