"Buster" wrote in message
news:%deaf.396481$tl2.700@pd7tw3no...
You'd be surprised how much static is built up on the system. If you're
moving it around the shop at all you'll want to ground it so you don't get
shocked every time you touch it... and continuously while your touching
it.

As the other reply points out people worry about dust explosions and such,
I agree with him I don't think it's a real danger.

Of course, grounding non-conducting material is a bit iffy. If don't want
to get shocked, you should be "grounding" the outside.

Now metal ducts and the odd woodscrew represent a real sparking danger.