If you look up Radio Shack, they sell 5 digit LCD debounced counters that 
run off a 1.5 V battery for ~$16. Use a minature reed switch and put a reed 
switch magnet on the armature. You are unlikely to exceed the maximum count 
rate of about 7 pps. It is actually not too hard to count the number of times 
you turn the handle if you are using a geared up hand drill.     An estimate 
good to a few % will be adequate. 

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