Hi, Adam.

Assuming the cross slide, the dial movement indicates the amount removed on the diameter. Half off radius (actual slide movement) equals amount off diameter.

Bill

My Chipmaster has dual dials, takes 400 thou off diameter. While the imperial dial is accurate the metric is not. If I zero the dial in "thous" then the cross slide will consistently return to the zero position, checked with a DTI, zero on the metric scale is inconsistent. Anyone else noticed that? I tend to use the DRO so not a problem, would be nice if it was accurate on both scales.

My Triumph has dual dials fitted, absolutely consistent in both ranges.

John

No 'of course' about it. Traditionally British lathes measure depth of cut. Measuring diameter (which I find more natural except when cutting threads) is a beastly American innovation circa 1890.

My Chinese mini-lathe dial measured depth, it's big brother measures diameter. Not much consistency in the world of lathes.

Always worth double-checking before using an unfamiliar machine.

Dave