Correct! Just because the bulk of surface grinders fall in the small category (6" x 12" or 6" x 18") doesn't mean they're not made larger. In fact, one of our readers, gcarsen, happens to own a 10' surface grinder. I'm not sure of the cross slide capability (Y axis), but it's likely to be 36".
Because Blanchard grinders are typically powered with huge motors, they are capable of performing much like a milling machine. They can move a frightening amount of metal, and are equipped with large wheels, with segmented inserts. The resulting surface may be somewhat coarse, although, given adequate spark-out time, assuming the machine has been properly set up, the resulting surface can be as flat as one generated by a linear surface grinder, and with a very nice finish, so a followup linear surface grind isn't necessary unless a straight line finish is desired.The second video I referenced above shows a big SG finishing a table saw top. The first video shows a Blanchard grinder flattening the same top before they used the surface grinder to remove the circular marks left behind by the Blanchard.
I'm kind of assuming that this was a two-step process because it would have taken forever to do the initial flattening on the surface grinder. Can somebody confirm that guess?
H