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Studio spline in sketch G1

Gears Phenom Gears Phenom
Gears Phenom

NX9

 

When creating a studio spline in a sketch, if I tell the spline I want it G1 to a line, at both ends, when I go back to adjust a pole in the middle, my "constraints" are gone.  Do they not stay?

 

If I create a geometric constraint, my spline becomes over constrained.

 

Is there anyway to control the tangency at the ends of my spline?

-Dave
NX 11 | Teamcenter 11 | Windows 8.1
13 REPLIES

Re: Studio spline in sketch G1

Valued Contributor
Valued Contributor

In sketcher - wouldn't you know it - it works differently. You have to apply a Slope of curve constraint at the endpoints, specifying them upon spline creation is not remembered.

 

Slope of Curve.png

Dan Iorga
Sulzer Pumps US

Re: Studio spline in sketch G1

Gears Phenom Gears Phenom
Gears Phenom
I will give that a try on monday. Thanks!
-Dave
NX 11 | Teamcenter 11 | Windows 8.1

Re: Studio spline in sketch G1

Legend
Legend

Another method is to add reference lines that are tangent with the end point connecting curves.  The second and second last poles are then located on the reference lines.  The advantage is that these poles can then be moved along the reference lines to change the spline.  That is the magnitude of the tangent is changed.  Below is an image showing this.

 

 

 

Frank Swinkels

Re: Studio spline in sketch G1

Legend
Legend

Another method is to add reference lines that are tangent with the end point connecting curves.  The second and second last poles are then located on the reference lines.  The advantage is that these poles can then be moved along the reference lines to change the spline.  That is the magnitude of the tangent is changed.  Below is an image showing this.

 

Image3.jpg

 

Frank Swinkels

Re: Studio spline in sketch G1

Siemens Phenom Siemens Phenom
Siemens Phenom

The G1 constraint for splines in sketcher was introduced in NX 10.

 

Before NX 10 working with splines in sketches is tricky. You can apply tangency and coincident at each end to a spline with 4 poles. Even in that case you have to ensure everything is constrained properly and something is fixed to the 'world'. 

 

I would advise you not to use a spline before NX 10. It is easier to construct a separate associative studio spline curve feature after your sketch.

 

Regards, **bleep**

Re: Studio spline in sketch G1

Legend
Legend

With the difficulties with sketch studio splines I thought I might look at what I could do with programming.  The attached zip file contains two programs and a dialog file.  The idea is that the first program is used to create a sketch studio spline.  The user can determine G1, G2, or G3 end continuity.  If the sketch is modified then the second program can be used to update the spline.  This is for NX9.  Also this is a first pass as I have not included Radius constraint or shape control.  If the programs are of any use I am happy to look at including these spline controls.

 

Frank Swinkels

Re: Studio spline in sketch G1

Creator
Creator

Hello Dan,

 

Thank you for this solution. With the slope constraint it works as requested.

Do you know a way to make this constraint work as the other constraints by selecting the spline and then chose the constraint? It is somehow not consistent to the use of the other constraints.

 

thank you

ursus

Re: Studio spline in sketch G1

Valued Contributor
Valued Contributor

@ursus wrote:

 

Do you know a way to make this constraint work as the other constraints by selecting the spline and then chose the constraint? It is somehow not consistent to the use of the other constraints.

 


It works the same - you selected the spline control point you want tangency applied, then the line it should be tangent to, and the context will suggest Slope among other constraints. At least in NX10 that is how it works, which is consistent, and you can now constrain control points other than the ends (compared to NX8.5 where only ends were).

 

 tang.png

Dan Iorga
Sulzer Pumps US

Re: Studio spline in sketch G1

Creator
Creator

Hi Dan,

 

Thank you! Yes it seems to work with lines within the sketch. I was using it with an intersection curve of a face next to the scetch. Therefore I needed to use the "old" way of creating constraints.

 

at least it is managable now...thank you

 

regards,

Urs