A dust collector is hooked up to two grinders and the drill press. It's the small harbor Freight one and is vented outside via flex tubing. The outlet on the side of the garage with a screen over it to keep varmets out. It was initally noisy outside, so I made a muffler from a 5 gallon plastic can with a plywood baffle with holes drilled in it. The holes area were much greater in size than the 4" flex tubing area, hey, it worked well, has great suction for grinding and buffing. The shop cat dosen't care for it so leaves when turned it on.
Only metal is ground in the shop, no knife handle material, wood dust and grinding sparks don't mix.