Looks painful -- I hope you heal quickly and fully!

There are some good ideas above on general grinder safety -- let me add a few more...

Get into the habit of holding the grinder out away from you until the wheel comes up to speed, so that if the wheel were to come apart from centrifugal force (usually from a crack resulting from being dropped or otherwise grossly abused), you are out of the line of fire when the pieces fly out away from the spindle. Wheels generally only let go upon startup or if they dig in and bind.

Always check yourself for loose ends (can be long hair, scarves, loose sleeves, untied laces, etc.) before starting the motor. Any of these things can easily get sucked into the the grinder and wound up around the shaft, pulling you into the spinning wheel or vice versa. You short-haired folks may have less of a problem with that, but I am a hippy. <img src="/forums/images/graemlins/pfft.gif" alt="" />

There are two main trouble zones on a grinder:
* the sparks exhaust out one side of the guard
* friction against the rotating wheel pushes the grinder opposite the sparks
Keep both clear of body parts, obviously, but keep the former clear of flammables or windshields/painted surfaces which can be pitted/scratched/broken by flying metal. Perhaps less obvious, plan around the latter, as well, as that's the direction the grinder body will be deflected first if the blade digs in and jams (and keep ricochets in mind).

Don't even get me started on wire cup brush safety... I'm not certain such a thing exists without a full set of thick shop leather, and have simply resigned myself to extracting strands of wire from myself afterwards.

Randii