On 4 Sep 2009 at 23:29, Brian Lanning wrote:
As far as I know, there's no special rating for
commercial
applications. It's hard to fake an amp rating though. It either
draws that much power or it doesn't. Of course, a space heater draws
quite a lot of current and isn't a very good vacuum cleaner.
Remember that these are universal motors though and current drawn
under what load conditions matters a lot. I still have the 10 amp
vac; I should see what a clamp-on ammeter says during normal
operation. I
Right now, cyclone dust collectors are all the rage.
They have
filters for only the very finest of dust, like 1 micron or so. The
rest is fed through a specially shaped chamber that spins the air and
uses centrifugal force to separate out the sawdust. It hits the sides
of the container and falls into a barrel below.
That's been the rage for a few years with consumer upright vacs,
particularly with the Dysons. The problem of course is that the
final filter is usually fairly expensive and slowly clogs during
operation. I've had a couple of the cyclonic ones and went back to a
double-layer disposable bag. I figure it runs about the same amount
of money for the same performance and I get like-new performance
every time I dump the bag.
Cyclonic may work well for wood debris, but I wouldn't give you a
plugged nickel for a shop vac with cyclonic separation sucking up
sheetrock sanding dust on a foggy winter day.
For woodworking, there's this "nominal"
crap. 3/4" plywood is sold as
3/4" "nominal" plywood. It's really 1/32" thinner. That may
not
sound like much, but it's the difference between a tight fit or not,
and having tools that exactly match the plywood thickness or not. And
they're all off a little depending on who made the plywood. Is it
really so hard to measure it out to 3/4"? I'd be willing to pay for
the extra wood. :-/
And a 1x2 isn't 1" x 2". It's been that way forever. The plywood
I've purchased over the last 3 decades have all called out the actual
finished sanded thickness. Is unsanded CDX the actual "nominal"
thickness? I think so.
The quality of the veneers used in modern plywood bothers me more
than a 1/32" thickness variation. The mills don't even have the
equipment to handle big peeler logs anymore--they'll even take 5 and
6 inch logs as veneer. It ain't what it used to be.
Cheers,
Chuck