I've been doing more belly-crawling this last week or so than I've
done since the days of carrying an M-14 and running, crawling,
slithering through the jungle in a little green suit. I'll tell you,
it's a little more physically demanding to do at 63 than it was at
20-21.

I'm in the process of running 120/240 VAC power as well as low-voltage
signal wiring to an underfloor grid in the crawlspace under my
workshop. I'm tired of tripping over power cables laying on the floor
(I'm a klutz- I admit it) and decided to go ahead with the low-voltage
signal wires when I took care of the power distribution. The signal
wiring is for a DC control system similar to that designed and
described by Robert Reed in Issue 91 (Feb, 2005) of Woodwork Magazine
(www.woodwork-mag.com).

That DC control system is designed to sense the current flow and
automatically turn on the DC when a power tool is turned on. (See the
article referenced above for details.) That is all well and good, but
I'm somewhat lazy as well as being klutzy and would like the DC blast
gate to be automatically actuated as well. Of course, that requires
some kind of actuator.

I'm aware of the EcoGate line of DC products which looks pretty good
(http://www.ecogate.com/blast_gates.htm). But, the MSRP of $85/4",
$149/5", and $248/6" makes me want to investigate other possibilities.
Especially since I've tried to follow Bill Pentz's advice and used 6"
S&D piping (http://billpentz.com//woodworking/cyclone/index.cfm). $248
per gate has a pretty high shudder factor. I'm perfectly willing to
invest sweat-equity to bring the out-of-pocket expense down to a lower
value.

How much lower? shrug I don't know. As low as I can get it. And if
that's still too high, I'll forget it and stick with the "armstrong
method".

So the question (finally) is: Does the wealth of experience and
knowledge resident in this group point to any fairly reliable and
inexpensive actuators that could be used to open/close a DC blast
gate? If so, I'd be very grateful for any advice you'd care to throw
my way.

An electro-pneumatic actuator is possible, but would require a lot
more belly-crawling which makes that a highly undesirable solution. At
first thought, electrically powered linear or rotary actuators would
seem to be preferable. It doesn't even have to be servo-controlled. I
can design and build a simple controller, if needed. Full open/Full
closed are the only positioning requirements.

I'm in the process of running 120/240 VAC power as well as low-voltage
signal wiring to an underfloor grid in the crawlspace under my
workshop. I'm tired of tripping over power cables laying on the floor
(I'm a klutz- I admit it) and decided to go ahead with the low-voltage
signal wires when I took care of the power distribution. The signal
wiring is for a DC control system similar to that designed and
described by Robert Reed in Issue 91 (Feb, 2005) of Woodwork Magazine
(www.woodwork-mag.com).

That DC control system is designed to sense the current flow and
automatically turn on the DC when a power tool is turned on. (See the
article referenced above for details.) That is all well and good, but
I'm somewhat lazy as well as being klutzy and would like the DC blast
gate to be automatically actuated as well. Of course, that requires
some kind of actuator.

I'm aware of the EcoGate line of DC products which looks pretty good
(http://www.ecogate.com/blast_gates.htm). But, the MSRP of $85/4",
$149/5", and $248/6" makes me want to investigate other possibilities.
Especially since I've tried to follow Bill Pentz's advice and used 6"
S&D piping (http://billpentz.com//woodworking/cyclone/index.cfm). $248
per gate has a pretty high shudder factor. I'm perfectly willing to
invest sweat-equity to bring the out-of-pocket expense down to a lower
value.


Had this in the back of my mind, when the blast gate is opened, a window
type burglar alarm sensor opens or closes, (haven't thought that far yet) a
circut to a relay to start the DC. Window sensors are a few bucks each,
relay 25/30$
Close the blast gate, DC shuts down.

"Rick Samuel" said:

Had this in the back of my mind, when the blast gate is opened, a window
type burglar alarm sensor opens or closes, (haven't thought that far yet) a
circut to a relay to start the DC. Window sensors are a few bucks each,
relay 25/30$
Close the blast gate, DC shuts down.

What you are envisioning should work perfectly. The same author I
mentioned before, Robert Reed, had an article in Issue 98 (April 2006)
of "Woodwork" describing such a system. He used mechanical lever/limit
switches but magnetic reed switches should work just as well. That
article has schematics for a system and plans for a blast gate also.

I recall seeing a similar system description in one of the WW
magazines within the last few months that did use magnetic reed
switches, but I cannot recall which issue of which magazine. But, it
should be a simple matter to substitute reed switches for lever
switches in Robert Reed's design.

I suspect that I'll wind up with manually operated blast gates in
spite of my desire to automate that part of the system. Hmmm, wonder
if an automotive door lock actuator could be adapted to open/close a
blast gate. Would mean transforming and rectifying 120VAC to 12VDC and
running low voltage power lines, but that's doable.

Tom,

I installed the low voltage system in my shop some time ago and am very
happy with it. I thought Robert Reed was going to do an article on a blast
gate opening system and had e-mail correspondence with Woodwork magazine
about this. I too think the ecogate system is out of reach for me with 6"
blast gates.
They posted my e-mail in the letters section to see if there was enough
interest in this subject. If there was they thought they might approach Mr.
Reed and see if he could design such a system.
Maybe if you and others contact the magazine we can get something like this
done.

Bob Heveri
Tom Veatch wrote in message
...
I've been doing more belly-crawling this last week or so than I've
done since the days of carrying an M-14 and running, crawling,
slithering through the jungle in a little green suit. I'll tell you,
it's a little more physically demanding to do at 63 than it was at
20-21.

I'm in the process of running 120/240 VAC power as well as low-voltage
signal wiring to an underfloor grid in the crawlspace under my
workshop. I'm tired of tripping over power cables laying on the floor
(I'm a klutz- I admit it) and decided to go ahead with the low-voltage
signal wires when I took care of the power distribution. The signal
wiring is for a DC control system similar to that designed and
described by Robert Reed in Issue 91 (Feb, 2005) of Woodwork Magazine
(www.woodwork-mag.com).

That DC control system is designed to sense the current flow and
automatically turn on the DC when a power tool is turned on. (See the
article referenced above for details.) That is all well and good, but
I'm somewhat lazy as well as being klutzy and would like the DC blast
gate to be automatically actuated as well. Of course, that requires
some kind of actuator.

I'm aware of the EcoGate line of DC products which looks pretty good
(http://www.ecogate.com/blast_gates.htm). But, the MSRP of $85/4",
$149/5", and $248/6" makes me want to investigate other possibilities.
Especially since I've tried to follow Bill Pentz's advice and used 6"
S&D piping (http://billpentz.com//woodworking/cyclone/index.cfm). $248
per gate has a pretty high shudder factor. I'm perfectly willing to
invest sweat-equity to bring the out-of-pocket expense down to a lower
value.

How much lower? shrug I don't know. As low as I can get it. And if
that's still too high, I'll forget it and stick with the "armstrong
method".

So the question (finally) is: Does the wealth of experience and
knowledge resident in this group point to any fairly reliable and
inexpensive actuators that could be used to open/close a DC blast
gate? If so, I'd be very grateful for any advice you'd care to throw
my way.

An electro-pneumatic actuator is possible, but would require a lot
more belly-crawling which makes that a highly undesirable solution. At
first thought, electrically powered linear or rotary actuators would
seem to be preferable. It doesn't even have to be servo-controlled. I
can design and build a simple controller, if needed. Full open/Full
closed are the only positioning requirements.