Les,
you are probably using a 6" profile wheel not an 8" - if you try to use an 8" wheel on the MK880 you won't be able to close the guard. If you are using an 8", MK recommends a 6"wheel for that saw.
Although I like the router bits that go on grinders very much for slabs, for unset tiles I prefer the profile wheel as there is less room for user error.
The lip may be for a couple of reasons. The first is that you are not aligning the tiles up in the correct spot and the second (and more likely reason) is that you are using a wheel with a bigger radius than you need to with the thickness of your tiles. If you are using a profile wheel with a 1/2" radius that could cause your lip (a real obtuse corner, right?). You might try a 3/8" radius profile wheel.
You should not have to cut the piece to keep it from bogging. There is no less resistance during the actual grind of a piece regardless of the length. Are you using this saw on a 20 amp circuit?
Your saw motor is plenty strong enough to profile tiles with.
The bogging down is not to be expected unless your profile wheel is glazing on the material. Here is a fast cutting profile wheel that is low priced and will cut granite & even porcelain. Try this:
http://www.defusco.com/brazed-profile-wheel-38%E2%80%9D-radius-p-1273.htmlWhen you are done shaping the tiles, get out your variable speed grinder and try these dry polishing pads to match the gloss with the face of your tiles:
http://www.defusco.com/diamond-polishing-pads-backers-diamante-italia-dry-resin-polishing-pads-full-set-c-25_30_652.htmlIf you have questions please call us at 800-289-6834.
Glad to be of service,
Mark
