How to adjust motor using strobe disc

Another way to adjust motor to run at exact 33,3 rotations per minute is using strobe disc. Strobe disc, which you can download and print at any size, can help you determine when the rotation speed is right.

How to adjust motor using strobe disc

After drilling a hole in the middle and placing strobe disc onto your turntable, when running it, the disc will show grey belt where the bars are. When observed under the ordinary lamp (in Europe such light bulb is powered by 50 Hz electricity while in America it's 60 Hz electric current) the grey belt will indicate when your rotation speed is correct. When the speed is correctly adjusted to 33,3 rpm, the bars should appear stationary, that is human eye will be able to dimly distinguish individual bars.