I have successfully modeled a DNA/Helical staircase, but I simply don’t think that I did it in the most efficient manner. Basically I created two helix around a vertical line pertaining to their respective diameters (7’ and 4"). I ran into problems, however, creating the stairs efficiently though. My method was to use Sweep 2 to get a surface between the two helix and then divide the surface. Next in order to create the stairs, I split the surface with the divided curves and then projected each segment to the c plane to create a planar iterations. Finally I set the planararized surfaces back onto the double helix. I tried a polar array, but that doesn’t recognize the center helix. The tricky part is to match the negative space from the ends of the stair segments to the helix. Helix Staircase.3dm (790.7 KB)
Any ideas? I wish to teach my students this, but currently my method takes far too long.
Thank in advance,