need suggestion for surface grinding wheel

Al, you want a nice new White wheel, about an 80 to 120 grit.

Take a Magic Marker, and swizzle it around the top of the chuck. Dress the wheel square, and take cuts of no more than a couple tenths per full pass. When the magic marker is completly gone, repeat once more, with magic marker, make another couple tenths pass, , then its time to stop. Holes, gouges and pits will harm nothing. All you want to do is make sure its flat to the wheel travel, with no raised edges around the craters. If you have coolant..use it.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Are you sure about that Gunner? KO Lee recommends a 46 grit wheel and I've seen others recommend that grit on the web for dressing a chuck.

The blue 5SG (seeded gel)wheels made by Norton last far longer between dressings than any others I have used. They cost twice as much as the standard wheels, but are well worth it IMHO. See MSC Cat. page # 789 (online)

Randy

Al:

This is how I resurface magnetic chucks on surface grinders.

What I do is use a regular 46H wheel and course dress it (run the diamond very fast across the wheel) course dressing keeps the heat input down and leaves a course finish on the chuck. Some people may not like that sort of finish, if that bothers you then either fine dress the wheel, or go to a 60H wheel for your finish passes. When grinding the surface of the chuck I step over almost the full width of the wheel (about .400-.450 on a 1/2" wheel) on each pass. You have to watch for ANY heat buildup, meaning you crank fast and take a tenth or two for finish passes (that's .0001-.0002, not .1 ). Like others have suggested, use coolant if you have it.

BTW, the "H" is a soft wheel, as the alphabet rises "J", "K", "L" the wheels get harder.

-- BottleBob

I dont know what KO Lee recommends. Only what was recommended to me by a guy who runs a grinding shop. I think he has about 15 surface grinders in daily operation. He may be doing it wrong. When I followed his directions, my chuck came out fine. I took very very small passes, so the fine wheel had no tendency to burn. Which the courser wheel would help prevent of course.

So yes..Im sure what the owner of Matthews Gauge told me, not that its right. Shrug.

Gunner

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Well, I'm not sure that a 46 grit wheel is better either, only that it's what the KO Lee docs recommend, as they happen to be in hand. A brief look through some books in the "library" didn't turn up anything relevant so I was hoping the reply might stir some discussion.