Bearings are tough to source if looking for both good and cheap. Local bearing places need a good markup so tough to get good prices on the small stuff we buy. Accurate Bearing is pretty good. Usually NTN, Nachi, good Japanese but not FAG, FAfnir, Barden, SKF. Most sealed or shielded are standard precision ABEC-1 stamped steel cage. Explorer are ABEC3 so rated for a little higher rpm. The old machines I run usually had open phenolic cage precision ABEC 5-7 that are very expensive but decent if you can find on ebay. When you are dealing with woodworking machines you are often dealing with spindle bearings rather than motor bearing applications. Motor bearings are usually C3 clearance to handle the heat. High rpm applications get looser clearance too. The more precision the bearing, the tighter the clearace can be so they are good in a spindle application like a shaper, planer, jointer etc. Probably more than you cared to know but seems like few understand much about bearings. Me included. Dave