Hi OSTexo, you can specify the length of the central axis line of the helix by using distance constraint when you are drawing that part of the helix, but no there is not any method to specify the length that would be traveled by walking along the helix path itself.

Do you also want to have the helix created at a known radius value? If so then you could create the helix at some size that you know will be longer than what you need, and then place some points along the curve spaced at the distance you need and then trim the curve with those points.

To place a point at a specific distance traveled along the curve, start by placing one point at the start of the curve, then select it and run Transform > Array > Curve and use the distance parameter in that array curve command to make a copy of the point at the distance that you need.

- Michael