At 02:24 PM 10/3/2009, Karl Wolz wrote:
>Seems it would be difficult to maintain an even 60rpm, or any other rpm,
>without some sort of a readout.  I can't afford a drill like that.

Any divisor of 3600 (or 3000 if you're in Europe and most other
places) can be easily checked with a *single* *standard, not CFL*
fluorescent bulb, by marking a rotating disk with <divisor> evenly
spaced marks.  Once you're in the ballpark, slowly alter the speed
until you see the pattern of n lines crawl to a stop with no ghost
images.  Your speed will be as accurate as the local power frequency,
which in the US is pretty good.

d