Editing Bench grinder (section)

==Wheel dressing==
Bench grinder wheels sometimes need to be restored to [[roundness (object)|roundness]] and given a fresh grinding face with newly exposed grains. New wheels have suitable balance when first made, but whether the balanced state will last after the wheel has been mounted, and (especially) after it has been in use for a while, is "quite uncertain".{{sfnp|Machinery's Handbook|1996|pp=1105–1109}} It can seem [[counterintuitive]] that they could wear as unevenly as they sometimes do, but a slow spin of the resting wheel by hand confirms it by showing the gap between wheel and tool rest varying substantially as the wheel turns. Thus it is normal that wheels sometimes need to be dressed (neatly trimmed), which is achieved by any of several types of [[grinding dresser|wheel dresser]]. When bench grinders vibrate excessively, it is usually because the wheels have worn out of round and are thus out of balance. Truing them by dressing usually resolves this problem. Although some consumers might imagine buying a bench grinder and then using it for many years without thinking about wheel dressing, the need for dressing is not so seldom as that. Correcting the imbalance not only reduces the annoyance of vibration (which rattles the wheel guards and shakes the workbench) but also is important to prevent premature failure of the spindle bearings, as heavy vibration beats them excessively.

It is also possible to arrange the weight distribution of the wheels for better balancing. There are several methods of doing this, all being conceptually analogous to [[tire balance|tire balancing]] with wheel weights. Most bench grinders never have these operations performed, because wheel dressing alone is enough to keep them sufficiently balanced, but these additional methods are not unusual for bench grinders and are quite common for [[machine tool]]s that do grinding, such as [[surface grinding|surface grinders]] and [[cylindrical grinder]]s. This is sometimes achieved by drilling a few holes in the steel [[flange]]s that hold the grinding wheels and then finding the angular orientation at which the holes' lack of weight balances out a heavy spot elsewhere on the rotating mass. Another method is a dedicated type of large flange with little weights that can be screwed down wherever needed for balancing (called a balancing flange.{{sfnp|Machinery's Handbook|1996|pp=1105–1109}}