Re: [CAD_CAM_EDM_DRO] Bar stock / Spindles

> As for dial indicators, the good ones have jeweled bearings, and I have
> one that directly reads out in .0001" marks. I can pretty much resolve
> variations down to .00001" on that indicator, without any backlash or
> slip/stick effects. If you want to know if a diameter is consistent or if
> it is out of round, this will clearly show it, even if the exact reading

is

> not valid. (If the axis of the indicator is not perfectly normal to the

work,

> then the calibration is off.)
>
> Jon

This has probably already been done but couldn't you test if the cylinder
had sides (Cheap skate style) by listening to it? If you were to mount an
electric listening probe into the tool post and hold it against the bar, any
lobes the probe's tip passed over would sound like knocking wouldn't it?
Just a thought, working along the idea that the probes listen for quite high
frequency, small amplitude, vibrations.

John H.