Hi geekmidget,

> Why doesn't MoI3D allow making a mathematically exact helix with constant radius and
> variable pitch, if AFAIK it allows making mathematically exact circles and archs? This was with
> MoI3D V4, I haven't tried with V5 yet.

It's because it's not possible to represent a 100% exact helix with a NURBS curve.

NURBS can represent exact circles, ellipses, parabolas, and hyperbolas but not helixes.

So a helix curve will be approximated.


> In some places the helix doesn't match the radius it should
> have, accuracy is off by a few microns.

That's normal. If you need a helix with greater accuracy than a few microns you will probably need to use some specialized CAD software that represents it as a procedural curve instead of as a NURBS curve.

- Michael