What would be the simplest way to build an RPM meter to measure the rotational speed of another device?
I have a drill press and I'm thinking of changing out the step pulleys used to transmit the power from the motor to the chuck. (I need it to run slower and with more torque)
The current step pulleys have a nice little chart with the approximate RPMs. If I find pulleys to work the way I want, I'll have to figure out the new rotational speeds of the new pulley ratios. I can think of a couple of possible ways to go about it, but was wondering if folks might have suggestions I didn't think of. (I have a lot of shields and parts already and this doesn't need to be a dedicated meter - I just need to read it once, right it down and be done. I don't care if I read it on the larger diameters of the largest step-pull or using something connected into the chuck of the drill press itself, but I do need to measure the chuck speed and not the motor speed)