Vac Experiment 2
 

Another question I have regarding shop suction - I have a nice 220 v.
dust collector, and am trying to build different hookups for the
various tools. One is a 12" sliding compound miter box,for which I
need
some kind of "hood." What I see making is a big box to sit behind the
tool
with a cavernous arched opening to accomodate its swing and the hose at

the bottom. That's the best I can come up with. The tablesaw didn't
come with a hose attachment on the blade housing, so I just stuck a
sheet
of plywood in the bottom of the enclosure with a hose-hole, and it
works
really well.
My shop is connected to a storage facility with million-dollar
vintage cars belonging to the landlord in it, so I have to watch my
ps&qs
with the dust, especially since it's one forced air heating system for
the
whole building.

I do not see a question. Do you have one?

" wrote:

Another question I have regarding shop suction - I have a nice 220 v.
dust collector, and am trying to build different hookups for the
various tools. One is a 12" sliding compound miter box,for which I
need
some kind of "hood." What I see making is a big box to sit behind the
tool
with a cavernous arched opening to accomodate its swing and the hose at

the bottom. That's the best I can come up with. The tablesaw didn't
come with a hose attachment on the blade housing, so I just stuck a
sheet
of plywood in the bottom of the enclosure with a hose-hole, and it
works
really well.
My shop is connected to a storage facility with million-dollar
vintage cars belonging to the landlord in it, so I have to watch my
ps&qs
with the dust, especially since it's one forced air heating system for
the
whole building.

It was somewhere outside Barstow when "
wrote:

One is a 12" sliding compound miter box,for which I
need some kind of "hood."

You rarely need "some sort of hood" for sawing. The chips are
reasonably large, so they don't "float" like sanding or even routing
dust.

Try making a _shallow_ hood instead, with a horizontal slot. You might
even build this into the fence, by boxing the back and routing slots
near the bottom of the fence. If you make these slots deep (along the
airflow axis) and with rounded edges into the airbox then you improve
laminar flow and improve "dust grabbing" range.

The idea is that the efficiency of dust and chip collection depends on
the air velocity passing into the duct. For a fixed mass flow (i.e.
input power) then this can be improved by using a small cross section
to keep the velocity high.

If you make a large hood, then it probably intersects every dust
particle going, but catches very few of them. Increasing the power
either puts the pipe velocity up (noisy) or sucks your toupee off.

I do not see a question. Do you have one?

- Jim Behning

Sorry to be vague, the intent of my post was to present my idea
for pros and cons.

In article .com,
" wrote:

Another question I have regarding shop suction - I have a nice 220 v.
dust collector, and am trying to build different hookups for the
various tools. One is a 12" sliding compound miter box,for which I
need
some kind of "hood." What I see making is a big box to sit behind the
tool
with a cavernous arched opening to accomodate its swing and the hose at

the bottom. That's the best I can come up with. The tablesaw didn't
come with a hose attachment on the blade housing, so I just stuck a
sheet
of plywood in the bottom of the enclosure with a hose-hole, and it
works
really well.
My shop is connected to a storage facility with million-dollar
vintage cars belonging to the landlord in it, so I have to watch my
ps&qs
with the dust, especially since it's one forced air heating system for
the
whole building.


I would start off by caulking and taping every crook and nanny through
which dust could escape. Then I'd put a stack of filters in front of the
cold air return. (Get them self-charging electrostatic ones from one of
the Borgs.)
Then continue with your other plans.