Dust removal question

This may seem like a dumb question, but wouldn't "gearing down" a shop vac by using 3-6" tubing onaccomplish the same as a dust collector.
I'm somewhat familiar with the same ideas if you want to move water. There are high flow, low pressure water pumps, then there are low flow, high pressure pumps.

Or perhaps the answer comes back to HP. I recall someone posting on here that shop vacs come nowhere near their advertised Hp, but that dust collectors take the high road by giving you an honest HP rating.

The bit about horsepower advertising is true (more or less). Going over 1.5 hp or so is physically impossible with 12-amp 110v motors.

The impeller (fan) size makes a big difference, too.

But don't underestimate the ability of a good shop vac to pull air. The trick is just to get the nozzle close to the source of the dust. When sanding you can shove it up between the ways of the lathe (if the hose will fit...). Neither of them will ever pull shavings out of the air, though.

You will never be able to create the cfm with a shop vac that you can with a dust collector, because of the size of the impellar and amount of air flow it has. The continuous duty motor on a dust collector is far more suited to longevity over the motor on a shop vac which is designed for intermittant use, not continual use. No comparrison!

I think one of the main reasons for using a dust collector rather than a shop vac, is that a shop vac is designed for short duration cleanup. The motor in a shop vac spins really fast to create enough vacuum. This causes it to heat up quickly, and self destruct after an extended period. I speak from experience, and a dead shop vac. A dust collector motor does not have to work as hard, and the higher HP allows it to work over an extended period of time without failure. Both are noisy, but the high pitched whine of a shop vac gives me a headache very quickly.

You will move MUCH more air than a shop vac with a cyclone type DC and 14" impeller or even a good used squirrel cage blower fan/motor than you every would with a shop vac. It all boils down to the CFM of air that one can move with enough movement to do the job at hand.

You'll never catch the chips because they'll go everywhere. Get a curtain for those, and sweep/shovel 'em up at the end of the session. (Y'know, I oughta try this. :rolleyes: )

Just try to get the sanding dust with a dust collector. If you're having trouble with it because you don't have enough suction, then try directing compressed air towards the DC inlet.