Hello Barry,

there is a script called CCC (calculate curves curvature) and a curvature node with the psychodellic colors. The disadvantage is the node throws 255 new styles to the file. For each color of the rainbow one ;-) You will find it under Infos in the extensions. You can switch also to a radius mode, only useful when the curve has no straight segments. With scale factor 1 the lines shows you the center of the local radius. Min and Max radius is also evaluated. Useful for e.g. sweeps with a circle as profile. then you can compare local radius of the curve with the profile radius and know if the resulting surface will be squeezed.
Have a lot of fun with it, it was a lot of work;-)

Karsten