As an addendum to my post on grinding gibs, I ALWAYS surface grind with coolant, and coolant that's directed at the point of contact. Surface grinding gibs, that aren't held down with a magnetic chuck is a somewhat delicate task. made possible with carefully applying coolant at the point of wheel contact. I use two coolant nozzles, one that goes the width of the wheel, but another aimed RIGHT at the leading edge of where I'm grinding the gib.
I guess I may assume that MOST people use coolant on a surface grinder. Can't imagine not, as my parts grow rapidly with no coolant. Even with careful use of coolant, striving to get the coolant right into the wheel at the point of contact, it's tough to not get the part to grow with heat. Certainly dressing the wheel coarser gets a cooler cut, but then you sacrifice finish. It's a real balancing act between the dress speed, and what I feel is an acceptable fine finish on a ground part. Dress too fine, and even with coolant, your part can burn.
Fortunately the gibs I grind the most are nine inches long, and I have a ten inch sine plate. I can set my taper angle perfectly, using the sine plate, where using spacers under the gib, relies on an exact location to get the angle right. I also should point out, I grind the taper on the gib, before I cut the angles on both sides of the gib. Grinding the fully machined gib, with opposing angles on the sides plus the taper, with no magnet on, is too time consuming, as the wheel wants to push the unsupported side of the already angled gib down, rather than grinding material off. A process that I've fine tuned over 19 years, through the process of errors. Now that I know how to do it fast and efficiently, it's gotten boring.
I just watched most of the video that was linked to. Interesting techniques, but for me way too slow. I mill my gibs on a fifty taper mill using a 10 inch Kurt vice, using a 1 1/2 inch carbide round insert able milling cutter My gibs are all castings that are already tapered, however they're rough, not flat have no really square sides. I mill the width of the gib, that later will be angled, two at a time in the vice. The tapers are opposed to each other so my vice is sort of squeezing two parallel sides. But I use WOOD on both sides of the gibs, so my vice can really hold them with much better contact than with the rough cast surface. i usually run ten to twenty gibs at a time, so I don't go slow. Takes two passes per side to get my gibs into at least two parallel sides so I can clamp them to cut the tapers. Cutting the tapers is easily done by just laying a master taper gib onto a parallel, laying the gib to be milled on top of it, and then clamping the jaws of my monster vice. two passes with my button cutter per side of the gib. I do ten or twenty of one side, then raise my table and do the other side of the gibs. Takes about two hours to do the sides and the tapers from a raw casting to do about ten gibs.
Off to the grinder to grind the taper, and then back to the mill to cut the sides to the mating angle of my dovetail. I use the vice simply to hold a dovetailed cross slide with the dovetail UP. I cut a piece of OAK hardwood to exactly match the width between my dovetails, less the width of the gib. I simply slide the tapered gib into the space, and HAMMER it in, until it's tight I tap it DOWN to make sure it's seated, and then cut the top of the gib to the angle in TWO passes, making sure my cutter is going in the direction that it would TIGHTEN the gib into the taper, instead of backing it out. I run all of one side, and then readjust heights and then do the second side. At this point the gib is right at the same height as the top of my saddle I'm using as a fixture. Doing gibs ten at a time, I may have twenty minutes a gib, from casting to completely machined and ground. My only "fixture" is one carefully ground tapered gib I use as a master, and then one cross slide i use for cutting the side angles.No finicky adjustments, but most of important is I'm blasting the material off in the mill using a robust mill, a huge vice and a cutter that cuts the entire width in one pass. despite the production line method, my gibs are FLAT because I'm able to grind them without having the magnet on, in the surface grinder. Whatever stresses my material had are gone because they were ground without the magnet.