Inventor General Discussion

## Inventor General Discussion

Valued Contributor
Posts: 71
Registered: ‎06-21-2013
Message 1 of 5 (550 Views)

# 2D equation curve for a parabolic spiral

550 Views, 4 Replies
06-22-2013 05:19 PM

Can anyone please advise me what the 2D or 3D equation curve for a parabolic spiral, otherwise known as a Fermat's spiral would be?

I have found this info but do not know how to apply it:

Fermat equation

Therefore in terms of the affine plane its equation is

The Fermat curve is non-singular and has genus

I have also found this: $r^{2}=a^{2}\theta$

*Expert Elite*
Posts: 28,046
Registered: ‎04-20-2006
Message 2 of 5 (519 Views)

# Re: 2D equation curve for a parabolic spiral

06-23-2013 07:00 AM in reply to: CJ.10E-10mm

Are you familiar with using Equation Curves in general?

A while back I posted some examples that my students submitted.

I think Autodesk employee has also posted some examples.

At one time there were several that were included in the Samples install, there should be a thread here with those attached.

Do a search and come back with more questions if you can't find the examples to help you work it out.

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Valued Contributor
Posts: 71
Registered: ‎06-21-2013
Message 3 of 5 (505 Views)

# Re: 2D equation curve for a parabolic spiral

06-23-2013 09:17 AM in reply to: CJ.10E-10mm

Thank you, I will search later today.

Equation Curves do appear to a novice like some form of 'black art.' So I am wondering if there is a 'user friendly; App that allows one to configure the equation for any given shape in an Excel Spreadsheet?

Thank you once again.

Distinguished Mentor
Posts: 909
Registered: ‎04-11-2005
Message 4 of 5 (496 Views)

# Re: 2D equation curve for a parabolic spiral

06-23-2013 11:09 AM in reply to: CJ.10E-10mm
If you can create x,y,z coordinates in a spreadsheet, IV will import them and draw a spline through them.
Valued Contributor
Posts: 71
Registered: ‎06-21-2013
Message 5 of 5 (478 Views)

# Re: 2D equation curve for a parabolic spiral

06-23-2013 03:11 PM in reply to: rdyson

Thank you Rdyson.

Is there any chance you could assist me with my question on:Variable pitch helical coil with smooth blend please?

Thank you once again.

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