I just acquired one and haven't found much useful info on using them on line. It's a Taiwanese clone of the Baldor, with two green wheels whose faces are angled from apparently freehand use. My use would most likely be guided sharpening of brazed threading and cutoff bits and freehand touch up of boring bars.
If they would be more useful I have diamond angularly worn 6" and chipped
3-1/2" cup wheels plus a variety of AO wheels with 1-1/4" holes I bought for my surface grinder. jsw