I've got a laser brand grinder. It's similar to the Oregon. I use CBN wheels for sharpening the cutter and a 1/4" pink stone for the DG. I usually stick to 60/30/0 for semi and 50 or 55/25/10 for chisel. I do try slightly different angles periodically looking for that "perfect" cutting chain.
You may want to check the angle and degree markings on the grinder for accuracy. A digital angle finder and or protractor works great. My grinder was out a few degrees in almost every direction.
When I sharpen a cutter I use several small bumps of the wheel as to not over heat the cutter.
I also like to grind fairly deep into the cutter so the top plate actually gets sharpened by the side of the wheel. This also helps to keep the gullets cleaned out. ******Note that this is just my preference and some may disagree.******
Lots of light
Take small, very small "bites". You almost want the wheel to be brushing the cutter not grinding it. You may have to go around a chain several times if it's been rocked or abused.
I profiled my DG stone to have a slight concave shape. This way when I touch up my DG they have a slightly rounded profile. I also set the grinder head tilt to 10* for grinding DG. I find the profile of the stone combined with the angle of the head help make for a smoother cutting chain.
This is my grinder
