Re: [CAD_CAM_EDM_DRO] Re: noob laser question

Cristi wrote:

> Hi Jon,
>
> the optical sensor or the glue point and the brushes is just for the
> balancing operation. I need a point on the rotor that periodically
> breaks the 5 V to identify the heavy spot. The only problem to the
> optical sensor is it needs to trigger the signal in a window of about
> 5 microsecs ( the time you need to sweep one degree at 30 krpm ).

You are talking about trimming these rotors to tenths of a
milligram, and then put globs of superglue on them? Isn't that
going to throw off the balance? (I haven't calculated the G
force on a 2" rotor at 30,000 RPM, but I doubt the glue would
hold, anyway.) You'll never get a one degree wide pulse out of
the sensor (brush or optical) but you don't need to. You just
work off the leading edge, or the center of the pulse, you
really don't care how wide it is. Hmm, the periphery of a 2"
disc turning at 30,000 RPM is 15708 feet/minute, or 178
miles/hour. Not a good candidate for brushes and mechanical
contact.

Jon