Tried a DC to empty a shop vac bin?
 

Planning my next router table and thinking about dust collection. My shop
vac works great in my current router table, which is an open stand.

The next router table will have an enclosure for the router, and I want to
add a DC hookup to the bottom of the enclosure to also pick up dust/chips
that come through the bit opening. This made me think of one possible
configuration to use both a shop vac and the DC: Connect the shop vac 2
1/2" hose to the fence dust collection port. Have a 4" Y fitting built in so
that one branch picks up at the bottom of the router enclosure (build
something of a slope into the sides to help funnel chips down to the
opening) and the other branch cobbled into the bottom of the shop vac's bin
to empty it.

My big question is - what would this configuration do to the shop vac? The
normal air flow is coming in the inlet hose, into the bin, through the
filter, and out the outlet vent. With a shop vac connection in the bottom of
the tank, the flow would branch - some going through the filter and out the
outlet, and some going out the DC connection.

Wondering if someone on the wreck has tried something like this. How would
it actually work in practice? Would the DC flow starve the shop vac blower
for air? And if that was the case, would it basically end up being no
different than having the DC connected to the fence pickup through a
reducer? I've read that a shop vac has higher suction, but a DC moves more
air, so it seems that a shop vac would be better suited to pulling chips out
by the fence opening.

Tried a DC to empty a shop vac bin?
 

Keith Carlson wrote:
Planning my next router table and thinking about dust collection.
My shop
vac works great in my current router table, which is an open stand.

The next router table will have an enclosure for the router, and I
want to
add a DC hookup to the bottom of the enclosure to also pick up
dust/chips
that come through the bit opening.
snip

Check out the NYW design.

Norm solved this issue with his design.

Lew

Tried a DC to empty a shop vac bin?
 

On Oct 30, 11:52 pm, "Keith Carlson"
wrote:
This made me think of one possible
configuration to use both a shop vac and the DC: Connect the shop vac 2
1/2" hose to the fence dust collection port. Have a 4" Y fitting built in so
that one branch picks up at the bottom of the router enclosure (build
something of a slope into the sides to help funnel chips down to the
opening) and the other branch cobbled into the bottom of the shop vac's bin
to empty it.

I certainly haven't tried it, but my initial response is that your idea
sounds far more complicated than necessary. If a shop vac in the fence
has worked well so far, stick with it unless/until you have problems.
Once you make the router enclosure, you could always vacuum it out once
in a while, or hook up a straight 4" DC port there if you like. It
seems like the hassle and potential useless-ness of an
automatically-emptying-shopvac would be a lot more trouble than it's
worth.
How long does it take to empty your shop vac? I probably spend 3
minutes every 3 weeks on that (at most), so I definitely couldn't
justify spending an hour or several rigging up something that might or
might not save that time. Also, what if you turned your shop vac on
when your DC was off - wouldn't it start pulling dust from your DC bag?

My advice, for what it's worth: keep it simple, and don't fix what
ain't broke.
On the other hand, I'd be sort of curious to hear what happens when
someone hooks up a DC to a shopvac bin and turns them both on, so if
you have the time, go for it and let us know what happens.
Andy, whose shopvac-thru-fence chip collection has been more than
sufficient for his router table work

Tried a DC to empty a shop vac bin?
 

Keith Carlson wrote:

Have a 4" Y fitting built in so
that one branch picks up at the bottom of the router enclosure (build
something of a slope into the sides to help funnel chips down to the
opening) and the other branch cobbled into the bottom of the shop vac's bin
to empty it.

Wondering if someone on the wreck has tried something like this. How would
it actually work in practice? Would the DC flow starve the shop vac blower
for air?

I suspect that the shop-vac will end up sucking the air out of the DC
hose rather than the other way round. It's got way more suction power
than the DC does.

Chris

Tried a DC to empty a shop vac bin?
 

This is the one I'm currently building (with a few modifications):

http://www.delorie.com/wood/projects/router/

incorporating some of the dust collection ideas from he

http://www.woodworking.org/WC/GArchi...ohnsrtab1.html

I think it incorporates most of what you are wanting or, if not, can
spark some ideas about how you might want to do it.



On Tue, 31 Oct 2006 04:52:07 GMT, "Keith Carlson"
wrote:

Planning my next router table and thinking about dust collection. My shop
vac works great in my current router table, which is an open stand.

The next router table will have an enclosure for the router, and I want to
add a DC hookup to the bottom of the enclosure to also pick up dust/chips
that come through the bit opening. This made me think of one possible
configuration to use both a shop vac and the DC: Connect the shop vac 2
1/2" hose to the fence dust collection port. Have a 4" Y fitting built in so
that one branch picks up at the bottom of the router enclosure (build
something of a slope into the sides to help funnel chips down to the
opening) and the other branch cobbled into the bottom of the shop vac's bin
to empty it.

My big question is - what would this configuration do to the shop vac? The
normal air flow is coming in the inlet hose, into the bin, through the
filter, and out the outlet vent. With a shop vac connection in the bottom of
the tank, the flow would branch - some going through the filter and out the
outlet, and some going out the DC connection.

Wondering if someone on the wreck has tried something like this. How would
it actually work in practice? Would the DC flow starve the shop vac blower
for air? And if that was the case, would it basically end up being no
different than having the DC connected to the fence pickup through a
reducer? I've read that a shop vac has higher suction, but a DC moves more
air, so it seems that a shop vac would be better suited to pulling chips out
by the fence opening.

Tried a DC to empty a shop vac bin?
 

"Keith Carlson" wrote:


This made me think of one possible
configuration to use both a shop vac and the DC: Connect the shop vac 2
1/2" hose to the fence dust collection port. Have a 4" Y fitting built in so
that one branch picks up at the bottom of the router enclosure (build
something of a slope into the sides to help funnel chips down to the
opening) and the other branch cobbled into the bottom of the shop vac's bin
to empty it.

My big question is - what would this configuration do to the shop vac? The
normal air flow is coming in the inlet hose, into the bin, through the
filter, and out the outlet vent. With a shop vac connection in the bottom of
the tank, the flow would branch - some going through the filter and out the
outlet, and some going out the DC connection.

I've read that a shop vac has higher suction, but a DC moves more
air, so it seems that a shop vac would be better suited to pulling chips out
by the fence opening.


You've read correctly, and when you think about it, you sill see you
have answered your own question. If the vac has more negative
pressure, which way will the air flow at the DC/SV interface? If both
are running, the shop vac will be sucking air out of the DC system,
probably lowering the shop vac inlet suction to close to that of the
DC.

An interesting variation on your idea would be to include a flap valve
that allows flow from the SV to the DC but not reversed. Then when the
DC is running but the SV is not, you would likely remove material from
the SV's tank.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

Tried a DC to empty a shop vac bin?
 

"Andy" wrote:


Also, what if you turned your shop vac on
when your DC was off - wouldn't it start pulling dust from your DC bag?

But that is the beauty of this system! Whichever is full, you just
turn on the other to empty it, so you never have to worry with manual
emptying of either! Right? That would work, right? g
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

Tried a DC to empty a shop vac bin?
 

But that is the beauty of this system! Whichever is full, you just
turn on the other to empty it, so you never have to worry with manual
emptying of either! Right? That would work, right? g

Beautiful! I guess I just wasn't thinking about the "big picture"...
On a similar topic, on my way in to work this morning, I saw a
lawnmower with a "dust collector" on it - not just a bag for
clippings/leaves, but a full 50gal barrel right on top of the mower
deck, with a DC-type fan on top of that, connected by a large hose
coming up from the mower. Hey - sure is faster than raking.
Andy

Tried a DC to empty a shop vac bin?
 

"Andy" wrote in message
ups.com...
I certainly haven't tried it, but my initial response is that your idea
sounds far more complicated than necessary. If a shop vac in the fence
has worked well so far, stick with it unless/until you have problems.
Once you make the router enclosure, you could always vacuum it out once
in a while, or hook up a straight 4" DC port there if you like. It
seems like the hassle and potential useless-ness of an
automatically-emptying-shopvac would be a lot more trouble than it's
worth.
How long does it take to empty your shop vac? I probably spend 3
minutes every 3 weeks on that (at most), so I definitely couldn't
justify spending an hour or several rigging up something that might or
might not save that time. Also, what if you turned your shop vac on
when your DC was off - wouldn't it start pulling dust from your DC bag?

My advice, for what it's worth: keep it simple, and don't fix what
ain't broke.
On the other hand, I'd be sort of curious to hear what happens when
someone hooks up a DC to a shopvac bin and turns them both on, so if
you have the time, go for it and let us know what happens.
Andy, whose shopvac-thru-fence chip collection has been more than
sufficient for his router table work


Yeah, it definitely would be more complicated than necessary, but part of
the fun of a shop is experimenting and trying things out! Seems like it
could be ideal - combine the suction of the SV at the bit, but the high
volume of the DC moving dust and chips out of the inside. And of course, if
you had a shop vac on there, and a DC hose right there, who wouldn't think
"Hmm... why am I empyting this tank?"

If I find a cheap SV on craigslist or even on freecycle I'll play around
with it and see what happens.

Another way of getting past the question would just be to connect the DC
line to the shop vac tank with a blast gate. Leave it closed while using the
router table, then shut off the shop vac (wired to the same switch as the
router), open the gate and let it clean out the tank.