On 14 Dec 2006 08:27:42 -0800, "brianlanning"
wrote:

Leon wrote:
Having worn out a couple of different brand shop vacuum cleaners I can
honestly say that a dust collector kicks butt for not too much more money
and offers a lot more capacity and much less noise.

I have a 1.5hp dust collector, but I'm considering using a shop vac
also. The reason is that the volume and air velocity differences
between the two are different enough that I think a shop vac might be
better suited to certain jobs while a DC might be better for others.
For example, the jointer and planer definitly need a DC. But for
hand-held tools, I would opt for the shop vac.

Well on my jointer the shavings just fall down the chute into a box, I
don't see the point in hooking anything up to it. But then I
generally just edge joint with it, maybe face jointing produces chips
too fast to fall out on their own.

I tried to attach my DC to a reducer, then to a hose, then to the leigh
dust collection router attachment thingy. I wasn't too happy with the
results. It just didn't seem to suck hard enough to get all the chips.
I think the difference is the amount of dust created vs the size of
the area where the dust is being collected. On a planer, the cutter
head area is sort of large compared to the bit area of a router or the
space under a ROS. I'm sure someone can chime in with the science
behind volume vs velocity.

The impeller will have a relationship between CFM, how much volume of
air it moves, and static pressure, how much resistance from the size
and amount of ducting/hose it has to move the air through. A dust
collector is designed to move a high CFM at relatively low static
pressure. A vacuum is designed to move a lower CFM at relatively high
static pressure. If you choke down a dust collector to a small hose
it will move hardly any air.


-Leuf