Helix and Evolute

For space curves of constant curvature the evolute has the same constant curvature

The helices have the formulas
curve(t) = Rad*[cos(frq*t), sin(frq*t), slope*frq*t].
We choose frq = 1/(Rad*sqrt(1 + slope^2)) to keep the arclength of the helix constant under parameter changes. The normals of the helix are drawn until they meet the evolute, another helix with the same curvature.