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B) If correct on A, how to understand the dimensions? Perhaps a 36x9"
lathe has 36" between centers, and 9" is the max. diameter of basic
stock?

Right again. (well, the 9" is the distance from the bed to the center -
you may have trouble mounting 9"stock)


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Minor correction: I believe that 'swing' is actually the maximum
diameter of the work. 9" swing would mean 4 1/2" between the bed (rails
that the tailstock moves on) and the centerline.

Charlie