A cusp could technically be a (pencil) point.
A radius reversal is a much smoother transition where the direction of curvature changes where the center points lies on opposite sides of the tangency plane.
Hope that makes sense...
Remember...
[navy]"If you don't use your head,[/navy]
[navy]your going to have to use your feet."[/navy]
Tank627, I'm guessing you're contemplating Controlled Radius vs Radius. Basically Radius Reversals are undulations in the form of the radius. I've tried to sketch out a sample of a radius reversal.
'94 introduced the idea of a Controlled Radius as such; in the '82 version, the definition of Radius was what we now know as a Controlled Radius. There are functional differences between the two (picture a radius on a cam vs an edge-round on a workpiece for handling purposes) and thus the need for differentiating between them.
Jim Sykes, P.Eng, GDTP-S
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