USB Stuff

[Tony Duell]

> 
> > There are 2 specific places I don't use [compact fluorescent lights]
> > -- one is over the lathe (I am worried about a possible stroboscopic
> > effect making the machine appear stationary when it's not)
> 
> I actually wouldn't worry about that, for two reasons: (1) they have a
> relatively long "on" time (partly the long-persistence phosphor, partly
> the width of the mains voltage peak), and thus a rotating lathe, even
> if rotating at a multiple of the strobe rate, will look blurred rather
> than stationary, and (2) anyone who depends solely on the appearance of
> the moving parts to tell whether a lathe is on is so stupid as to have
> no business near power machinery in the first place (look at the power
> switch, listen for the motor, find a smooth rotating part and touch it
> lightly, the ways to tell are legion).

Most lathes (including mine) have a clutch between the motor and the 
chuck. The idea is you keep the motor running most of the time, engage 
the clutch when you actually want to do something ;-). So the part could 
be stationary even if the motor is running. OK, that's fail-safe (if the 
motor is silent, the machine certainly isn't turning), but a lot of the 
time you throw the clutch out, measure something with a micrometer, then 
let the clutch in again, so you tend not to notice the motor sound.

And of course you test by touching a smooth part first. And then one day 
you forget and get caught by one of the chuck jaws or something. Yes, it 
_is_ stupid. I admit it's stupid. But I like to have all the clues I can 
have.

-tony