Cancel
Showing results for 
Search instead for 
Did you mean: 

How to create a parabola by equations in NX10

Creator
Creator

Hi everyone,

 

Here is my problem :

I need to create a parabola with these equations :

 

X=t

Y=0

Z=t²/4*F

 

where " F " is the focal length (a value that I could change).

 

A tool already exists in NX (Curve -> More -> Parabola) but I have to create new curve everytime when I need to change the focal lentgth.

 

I would like to change just the paramater " F " in the " Part Navigator " to change the parabola shape.

 

Do you know if this is possible ?

 

Thanks in advance Smiley Happy

 

Playmo31

7 REPLIES

Re: How to create a parabola by equations in NX10

Siemens Phenom Siemens Phenom
Siemens Phenom
In Expression Editor create the following expressions
t=1
F=10
xt=t
yt=0
zt=t*t/4*F

Then go to Law Curve
simple OK to take the defaults

Steve V

Re: How to create a parabola by equations in NX10

Creator
Creator

Hi Steven,

 

Thanks for your quick answer.

 

When I try to write these expressions in Tools -> Expressions : Formula

NX says "Expression 't' not found".

 

Do I have to define 't' and the variable 'F' before ?

 

(I have never used the Expressions tools before :/ )

 

Playmo31

 

Playmo

Re: How to create a parabola by equations in NX10

Siemens Phenom Siemens Phenom
Siemens Phenom

 

Do I have to define 't' and the variable 'F' before ? 

Yes.

You have to define a expression first then you can use it in the formula of other expression.

Re: How to create a parabola by equations in NX10

Creator
Creator
Thanks Ganesh but how can I define these variable ?

Re: How to create a parabola by equations in NX10

Siemens Phenom Siemens Phenom
Siemens Phenom

Yes you first have to create the expressions first

You also have to create the expression t first as other expressions reference this.

Go to  Tools->Expressions

First change the type from Number - Length to Number - Constant

In Name enter t and in Formula enter 1

Press Apply

Actually it does not matter what value you give t it will change internally from 0 to 1 in the Law Curve feature.

Now do the same for the other values create F next as used in the expression later.

OK out of Expressions

Now go to Law Extension and simply OK

 

Steve V

Re: How to create a parabola by equations in NX10

Siemens Phenom Siemens Phenom
Siemens Phenom

Menu > Tools > Expressions (Ctrl+E)parabola.png

 

Re: How to create a parabola by equations in NX10

Siemens Phenom Siemens Phenom
Siemens Phenom

Another option is to use the Reuse Library. NX supplies 13 Law Curves OOTB in the Reuse Object Libary. The image below shows the menu for the parabola and the other curves that are available. You also get a menu to set the parameters when you insert the curve. After that you can either change the values from the part navigator as the curve becomes a feature, or in the expression system. 

 

LawCurve.pngInsert Law CurvesLawCurveExpressions.pngEdit Curves with ExpressionsEditLawCurve.pngEdit Curve via Part Navigator

 

Scott