how to dress a wheel on surface grinder

Depends on the wheel condition and what you're trying to accomplish. Personally, when I spent time on surface grinders, my objective was usually good surface finish, and often on hardened materials, which grind far better than do mild steel or other soft materials. At any rate, in order for your wheel to have a good surface, which helps translate into a good finish, my policy was always to plow off about .005" per pass, fairly quickly. You don't have to worry about over feeding the diamond if you're hand cranking, it will handle what you throw at it with that shallow depth, but the finish on the wheel will be somewhat coarse. Once you have the full profile of the wheel re-established, my policy was to take one or two shallow passes, .0005" at the most, slowly, so the wheel was left with a good surface. This dressing technique is important to the way I ground and may not be good advice for you-----so please read on.

While most of what you read will tell you to place your diamond away from center, so the wheel is pushing it out of the cut should it tip, my policy was always to dress as near center as possible, but with the diamond held at such an angle that any motion moved it away. The angle in question (maybe

15 degrees or so) was perfect for turning the diamond to keep exposing a sharp edge, so it's a win/win situation. My rational, and it's important for older machines, is if the spindle is no longer perfectly parallel with the table, you will still dress a surface on the wheel that is. Dressing away from center will dress a slight, but detectable, angle. That's important for achieving a good surface finish on parts (no, or minimal feed marks), particularly the way I ground.

How you grind makes a serious difference. Where grinding is used to remove stock, shallow plunge grinding and rapid saddle feed are often the method employed. I don't like it, and for several reasons. The surface finish sucks, as does wheel life. It works far better to take a cut of no more than .008" (when conditions demand, or permit) and feed the saddle slowly (.030"/.050") at the end of each stroke of the table. You always use the same edge of the wheel by this method, which will hold up surprisingly well, assuming you have matched the wheel to the work. When the shoulder breaks down to the point where you're starting to have a rough finish, it's time to dress the wheel to a full profile and start over, or do that when you've finished roughing the work at hand and it's time to go for size and finish. Finish passes, it should go without saying, should be very fine, no more than a thou, but a few tenths are even better----when you're working for finish and close tolerance. Unlike a machine that uses various cutting tools, an abrasive wheel has no trouble removing a few millionths, and improving finish in the process, so that's part of the secret to improving surface finish. None of this may make sense to you right now, but as you develop your grinding skills all of it will-----and it's excellent advice.

Sorry to say, when I left the shop, there was no such wheel on the market, so I'm not the person to ask. I'll step aside for those that have experience with them.

Harold