# Anyone know how to make a helix between 2 points?

Ok so I’m working on a spiral rail for a ramp but am missing certain dimensions I have the radius and end ramp height and start of ramp to end of ramp distance. I’ve created a generic rhino file and image as an example. But I was wondering if there is a easy way to create a helix in the z axis and pick the two points on the arc and have a helix generated between them at the proper height . I cannot figure this out for some reason. Thanks

rhino test.3dm (31.8 KB)

1 Like

Hi Jacob - not directly I guess - you need to first get the fraction of a circle that you need to cover , if I understand what you’re doing - (73.33/360, you can type that directly on the command line and Rhino will do the math to get you Turns=.203694 ) It makes perfect sense if the helix is less than one turn to be able to snap to points, but at the moment there is no provision for that that I know of.

-Pascal

Hi Pascal thanks for the tip. I can get the helix to occupy the fraction of the circle I need to cover now using your division example but I cannot get the height of the helix to be correct. I think I need another tip. Thanks

Hi Jacob - use the Vertical option setting up the helix and snap the axis to the start and end points you have in place - that will set the height exactly.

-Pascal

Thanks Pascal, that did the trick perfectly.