Bench Grinders: How To Keep Them Running True
The performance of your bench grinder can be improved with just a little time performing a few simple tune-up steps. The stamped steel flange washers may not run perfectly true and can be adjusted by making a reference mark on each flange washer and the wheel to record their original location.
Next, loosen the shaft nut and slightly rotate one flange washer clockwise and the other counterclockwise. These movements should only be about one-half an inch at a time; then snug up the shaft nut by hand and spin the wheel by hand. Observe any change. This rotation should minimize any oscillation caused by flange washers.
Now re-tighten the shaft nuts and dress the wheel. The center bushings supplied by aftermarket grinding wheel manufacturers are designed to roughly center the wheel on the shaft. The flange washers hold the wheel; dressing with a wheel dresser will make the wheel run true. Make sure the grinder is always unplugged during any adjustment or wheel changes.
If adjusting the flange washers does not make the wheel run without side-to-side oscillation, then remove the wheel and flange washers and check the shoulder on the motor shaft at the point where the flange washer seats against it. A slight burr on the edge of the shoulder can stop the flange washer from seating properly. This can be removed by using a file to smooth the edge of the shoulder. Look for any roughness on the surfaces of the flange washers and smooth these spots on sandpaper placed on a flat surface. Then replace the wheel, re-adjust the flange washers, and dress the wheel.
