Surface grinder wheel balancing is probably the most important (and often neglected) aspect of surface grinding. Using unbalanced or poorly balanced wheels is unsafe, can damage the spindle and makes it impossible to get good surface finish.
Static wheel balancing systems can be expensive and are not easy to setup. Here is a simple approach.
Sown is my Ingar 618 surface grinder, but the process is the same for all grinders. Only the wheel adapter might be different.
I am using precision ball bearings salvaged from an old hard-drive. Newer hard drives are using hydrodynamic bearings that are not suitable for this application. High quality stock ball bearings can be used as well, though in my tests were not as sensitive. Shields or seals must be removed (if present) and all traces of grease or oil must be washed off.
Sorry about the typos in the video text (noticed after posting). I was working on this video late at night...