1067 Views 30 Replies Latest reply: Jul 3, 2013 8:04 AM by TomD.inPDX
5,279 posts since
May 25, 2012
Currently Being Moderated

## Help!  Equation Solution Request.

How do I "define" a semi-circle by an equation when Y is linear?

I know the cartesian formula:

x = 4 * cos ( t * 180 )

y = 4 * sin ( t * 180 )

z = 0

But I need to compensate for the trajectory (Y) which has a linear value.

I need the formula applied only to X given Y is linear 0-1.

I want to sweep a VSS to make this shape.  The trajpar is the given value (t as Y):

• 362 posts since
Jan 25, 2009
Currently Being Moderated
Jun 13, 2013 10:37 PM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Dear Antonius,

I think that you can combine Sweep feature with Graph feature - the values of graph will be inputs for sweep trajpar relations.

Regards,

• 2,398 posts since
Sep 26, 2010
Currently Being Moderated
Jun 14, 2013 11:58 PM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Hi Antonius,

• 1,390 posts since
Sep 8, 2011
Currently Being Moderated
Jun 18, 2013 9:42 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

I'd love to help, but I **** at math!  I'd be graphing that baby!

• 362 posts since
Jan 25, 2009
Currently Being Moderated
Jun 18, 2013 11:45 PM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Dear Antonius

I have tried to create SEMICIRCLE BY SWEEP feature - it is working (you can investigate my model)

Note: I have used for sweep feature the Relation (for UPPER_HALF_OF_THE_SEMICIRCLE) sd4=(r^2 - (trajpar*r)^2) ^ (1/2)

Regards,

• 362 posts since
Jan 25, 2009
Currently Being Moderated
Jun 19, 2013 11:58 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

You are Welcome Antonius.

It was challenge for me too - I like Relations and Sweep feature too - it is powerfull combination.

Here is some old example

Regards,

• 1,390 posts since
Sep 8, 2011
Currently Being Moderated
Jun 26, 2013 8:18 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Cool stuff!  I'll definately have to look at the equations, thanks!

It is the bill of a ball cap?

• 1,390 posts since
Sep 8, 2011
Currently Being Moderated
Jun 26, 2013 1:24 PM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

I've seen weird things like that in boundary blends near corners.  IMO, Boundary blend was better and more robust before WF.

• 1,390 posts since
Sep 8, 2011
Currently Being Moderated
Jun 27, 2013 6:45 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Hmmmm, so the geometry ISN'T all weird like that?  Interesting.....

• 596 posts since
Jan 22, 2011
Currently Being Moderated
Jun 27, 2013 9:34 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

Does it fail to create the surface on the high quality settings if you actually confirm creation of the sweep? Or will it just create distorded surface?

This is like really really odd. The boundary of that surface shouldn't change at all, while the mesh of the surface could of course with the different display quality.

• 596 posts since
Jan 22, 2011
Currently Being Moderated
Jun 27, 2013 12:58 PM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

That's nasty.

Tom, could you also please show the curvature analysis of the curves in your video? Just so one can see these are not some crazy oscilating splines, but regular curves.

• 596 posts since
Jan 22, 2011
Currently Being Moderated
Jun 28, 2013 9:18 AM (in response to TomD.inPDX)
Re: Help!  Equation Solution Request.

You are welcome, I'm glad you got it working, and with so few features, really interesting approach.

Actually, I never knew portion of a surface can be cut out with another on-laying surface in Creo.

So, just to say again, learn something new everyday.

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