https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093174#M100856 <P>use this with polar:</P> <P>r(t)=5.75in+0.125in*sin(t*X)</P> <P>theta(t)=t</P> <P>t_min=0, t_max=360</P> <P>&nbsp;</P> <P>where X is the number of periods around.</P> <P>ps: you don't need the "in"-s if your unit is inches (mine's not.)</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-left" image-alt="Clipboard01.jpg" style="width: 705px;"><img src="https://forums.autodesk.com/t5/image/serverpage/image-id/357646i2019D92C92388094/image-size/large?v=v2&amp;px=999" role="button" title="Clipboard01.jpg" alt="Clipboard01.jpg" /></span></P> <P>&nbsp;</P> <P>&nbsp;</P> Thu, 18 May 2017 15:20:59 GMT bshbsh 2017-05-18T15:20:59Z https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093127#M100855 <P>I am trying to come up with an equation for this sketch. It is a 11.5 dia circle with curves measuring .25" per period. I need to go 360 degrees around the circle. Any suggestions? Thanks in advance</P> Thu, 18 May 2017 14:56:50 GMT https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093127#M100855 Anonymous 2017-05-18T14:56:50Z https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093174#M100856 <P>use this with polar:</P> <P>r(t)=5.75in+0.125in*sin(t*X)</P> <P>theta(t)=t</P> <P>t_min=0, t_max=360</P> <P>&nbsp;</P> <P>where X is the number of periods around.</P> <P>ps: you don't need the "in"-s if your unit is inches (mine's not.)</P> <P><span class="lia-inline-image-display-wrapper lia-image-align-left" image-alt="Clipboard01.jpg" style="width: 705px;"><img src="https://forums.autodesk.com/t5/image/serverpage/image-id/357646i2019D92C92388094/image-size/large?v=v2&amp;px=999" role="button" title="Clipboard01.jpg" alt="Clipboard01.jpg" /></span></P> <P>&nbsp;</P> <P>&nbsp;</P> Thu, 18 May 2017 15:20:59 GMT https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093174#M100856 bshbsh 2017-05-18T15:20:59Z https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093250#M100857 [image: Inline image 2]<BR />This was what I got when I imput the equation. What am I doing wrong?<BR /> Thu, 18 May 2017 15:36:18 GMT https://forums.autodesk.com/t5/inventor-programming-forum/equation-driven-curves/m-p/7093250#M100857 Anonymous 2017-05-18T15:36:18Z