【转帖】radius reversal

yang686526

radius reversal
exactly what does one look like?
a fillet
chris
systems analyst, i.s.
solidworks 06 4.1/pdmworks 06
autocad 06
picture two opposite arcs (not necessarily the same size radius) meeting end to end and the point of tangency (or radius reversal) between the two.
so its different than a cusp
the way i understand it, yes.
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...  
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.
i was just crunching the difference of ansi y14.5-1982 & asme y14.5-1994.
looks like a cusp & reversal are both not allowed in a "cr" or the 1982 version.
'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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cad-documentation-gd&t-product development
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