OK, so I'm still a rookie (complete!) at the shaper, and still getting the hang of it. I wanted to just try out a different tool bit on a scrap piece of aluminum. Keep in mind this is probably the 4th time I've actually applied power to my new (to me ) SB7. So I put the bit in the holder, the holder in the tool post and squared everything up. put my little scrap in the vise and got a good chip from each stroke, all was well. The tool was a bit too pointed, so I got this nice textured (ribbed?) finish that I actually kinda like. Not that I'll stick with that, but it was interesting. Anyway, I had once clean surface now, so I figure, lather rinse repeat. Loosen vice, rotate stock 90* and clamp er up again. This side has a 1/4" hole drilled through the middle, but I figure what the heck, its just scrap, lets see what happens. And this side goes through without a problem... Im kinda liking this! rotate the scrap and lets do it again. This side had two separate openings along one side where a previous couple of screw holes had met the saw blade when this side was cut. But again, lets see what it does. So liner up and let her go!.. the slots were on the far side so the first 3/4's went without a hitch. It even made it about two thirds of the way through the slots when there was suddenly movement I didn't expect. And before I could really react, the shaper had taken about 3 more strokes making a pretty different banging sound... Long story short, I had never checked the vice's anchor bolt. Everything seemed solid, and certainly the last guy hadn't used it with it lose! right!?!? Well, Im sure not! But apparently the interrupted cuts had been enough to loosen it up and allow the vice to rotate to about 35* counter clockwise from its intended position. So Lesson Learned! Always check the vise. And your first reaction to anything unexpected should be to reach for the power switch!!