One day, I played with a motor, that I extracted from defunct hard drive.
It has four leads, so plenty of choises. I just picked two, and attached them to multimeter(measuring frequency(Hz),
while the motor's axle was attached to lathe's chuck.
I managed to get the lathe to run, and multimeter says something, like '~80'
I have also a non-contact tach, and, to my surprise, it showed some ~800 rpm.
So the hdd motor shows the rpm, although 1/10 of it. Just move the decimal point.
It has four leads, so plenty of choises. I just picked two, and attached them to multimeter(measuring frequency(Hz),
while the motor's axle was attached to lathe's chuck.
I managed to get the lathe to run, and multimeter says something, like '~80'
I have also a non-contact tach, and, to my surprise, it showed some ~800 rpm.
So the hdd motor shows the rpm, although 1/10 of it. Just move the decimal point.