Okay I have used the equation driven curve to create this part. I cannot close the loop. So I added a line to each end point. I want the end result to look like this shown in the video at this link. Amazing NEW Papp Design flat super piston engine noble gass - YouTube

The calcs I used for trying to do this as posted in other forums: Xt=R*cos(2*pi*t) Yt=R*sin(2*pi*t) Zt=A*sin(n*2*pi*t) T1=0 T2=.9999. This creates the pattern But i need it to be a solid with a hole through the center of it. I have uploaded the model here. Thanks for any help.

Is this what you want?