Where does one place the blast gates??

[Glen Blanchard]

I have been reading some threads about underground/under-floor DC ducting. Although I will not be beginning construction of our new house (with workshop) for another three years, I know I will want my ducting placed in this fashion. However, it just dawned on me (DUH!!) that such an arrangement would place the blast gates near the floor for most stationary machines. Assuming one does not relish the thought of bending over to open or close these gates (and this ONE does not) what can be done to bring them to a more user-friendly height without introducing sharp turns in the ducting or installing an automatic gate system?

[glenn bradley]

My dad has them overhead just after the 6" turns to 4". He's not tall but can reach them easily. I place them where convenient if all ducting leading to the gate is rigid. Otherwise I place them where the rigid changes to hose. I would recommend against gating mid-hose, so to speak.

[Jim O'Dell]

What about making your own "choke cables" to operate the gates? I'd think that it would be do-able. And you conld mount the pull for each blast gate where it would be convenient for you...maybe close to the power switch? Just a thought. Jim.

[Steve Flavin001]

optimum system lies midway.

If I were in such a fortunate position (which I am not), I would install automated blast gates at each of the principal machines. Today's Rockler prices (illustratively) show $5 for an ABS manual gate and $13.5 for an automated gate (package of 3, $40), and they are probably slightly less from Grizzly or comparable. source. In any event these 3 might take care of the major machines, depending of course on how elaborate your shop is, and probably be 80% of all use.

Add a couple of manual for the less used remainder. Generally the manual gates would presumably be in line close to the machine to eliminate bends and as well to eliminate back and forth travel to open/close. Depending on the floor plan, one would envision the manual gates near each other close to the vac source, but that is wide open depending on spread of the system.

I'm sure its my own peculiarity, but I would not want my piping cast in concrete - literally or figuratively - and try for running it overhead as much as possible.

Given all the unknowns in your current thoughts, these are guidelines I would use for my first pass, were I planning one.

[Greg Hines, MD]

I do not have a central vac system, but when I do, I am putting the blast gates onto the tool itself, then attaching the hosing to it. That would put the gate up off the floor where it can be serviced if need be, and would be more convenient for using it.

Doc

[David DeCristoforo]

Every time the subject comes up I feel the urge to suggest looking into the EcoGate system. ( http://www.ecogate.com/ ). Ever since installing this system in my shop, the whole question of blast gate placement, switch placement, remote control, etc. has become moot. You turn on a machine. The blast gate opens. The dust collector fires up. You turn off the machine. The DC powers down. You never have to think about it. The only thing is that the "vibration sensors" are a PITA. Fortunately, they have a current sensor that is very easy to install, is much more reliable and only costs an extra seven bucks per machine.

Disclaimer: I have no interest in the EcoGate company. I just think that this is an excellent product that should be seriously considered as an integral part of a good DC system.

[Cody Colston]

David,

With the Ecogate system is there a concern with the DC cycling on and off with the machines? I normally leave my cyclone running until getting to a point where I won't need it for a while. Somewhere I read not to exceed six on/off cycles an hour.

[Jerome Hanby]

What about making your own "choke cables" to operate the gates? I'd think that it would be do-able. And you conld mount the pull for each blast gate where it would be convenient for you...maybe close to the power switch? Just a thought. Jim.

That make a lot more sense than my first thought, solenoids. I'm an electronics guy, so I guess if all you have is a hammer then every problem looks like a nail:D

[Jason Beam]

David,

With the Ecogate system is there a concern with the DC cycling on and off with the machines? I normally leave my cyclone running until getting to a point where I won't need it for a while. Somewhere I read not to exceed six on/off cycles an hour.

Cody,

David will certainly be able to answer this better, but I think that there's a time-delay before the system is shut off. I think it may even be adjustable so you might have it run for say 3-5 minutes between powering off the tool so as to let you adjust and resume cutting.

[Glen Blanchard]

I guess I worded my initial query poorly. Let me elaborate a bit. If one has their DC coming up from the floor, in order to get the blast gate up to a comfortable position (let's say 48" above the floor) the duct would have to run up this high, a gate placed, and then the duct would have to turn 180* to go back to the machine (near floor level). Of course the 180* turn won't work. So what am I missing here?

[Jason Beam]

Glen, I apologize for going off yer original topic. What i'd do is stick 'em down where it's best on the airflow and then work out various ways to operate them from "human hieght". The clutch cables are a great idea since you get both motions in one solution (opening and closing). Other methods i've seen involve levers that perform a similar task - some i've seen overhead, others i've seen down below.

Another simplistic system is to just extend the "handle" of your gate out to a more reachable location. You still might have to lean down, but you don't have to crawl UNDER things to get at 'em.

I've also seen some folks work up a pair of cords - one to open, one to close. Usually, though, I see these for overhead runs.

Another possibility is the EcoGate system that David mentions. It's a great way to avoid any and all gate troubles - just stick 'em where they need to be.

I think the answers you're getting do somewhat address your needs... either you do have to be horribly inefficient and run the duct up and back down to bring the gate to a point you can reach it - or you put the gate where it makes sense and find a different way to operate it.

[Glen Blanchard]

I'll probably go with the Ecogate solution as it will address my concerns and add convenience as well. I have known about these things for quite some time, but have never done any investigating. What I don't understand is how they sense that a machine has been turned "on". David???

[Jason Beam]

Since I seem to be lurking around, I'll keep babbling :P

The sensing systems that are used are one of two styles that I know of: Vibration or Electrical. The vibration ones have a little thing that you stick to the motor of the tool (i think) and it feels the vibration of the motor kicking in. The electrical method is wired in and senses the current draw for a given tool. I'm not sure if it goes between the power supply and the tool itself, or if it's just t'd off it but I hear that this method is the most reliable over the vibration ones.

[Doug Shepard]

What about making your own "choke cables" to operate the gates? ...

Maybe something like a reverse application of these?
http://www.sawmillcreek.org/showthread.php?t=58586

[Chris Padilla]

Since I seem to be lurking around, I'll keep babbling :P

The sensing systems that are used are one of two styles that I know of: Vibration or Electrical. The vibration ones have a little thing that you stick to the motor of the tool (i think) and it feels the vibration of the motor kicking in. The electrical method is wired in and senses the current draw for a given tool. I'm not sure if it goes between the power supply and the tool itself, or if it's just t'd off it but I hear that this method is the most reliable over the vibration ones.

It is usually just an inductive coupling to determine if current is flowing in the wire so there is no direct tap of the wire. Recall that current flow in a conductor produces a magnetic field around the wire. A piece of ferrite material around the wire will pick this field up thus creating a current and this current may then be sensed.

[David DeCristoforo]

"With the Ecogate system is there a concern with the DC cycling on and off with the machines?... I read not to exceed six on/off cycles an hour."

I have been using this system for six years now and I have not had any problem with it. My system might cycle on and off way more than six times an hour or it might only cycle six times a day. Depends on what I'm doing. But so far...no issues. It's is so much nicer to be able to forget about it. I used to leave it running because it was such a PITA to have to be turning it on and off all the time but the noise... my god the noise! Now my DC is housed in a "wart" I built outside the shop and the biggest "issue" I have is remembering to empty it out!

"...The electrical method is wired in and senses the current draw for a given tool. I'm not sure if it goes between the power supply and the tool itself..."

The "original" current sensor was a coil that you passed one "leg" of the power cable through. It was very small and would fit inside most switch boxes. The "new" ones are designed to simply clamp onto the power cord so they are very easy to "install". The vibration sensors bite big time. I was always having my DC power up every time I plopped something down on a saw table. Or the stupid things would pop off and not work at all (they were attached with "sticky backed" velcro). The current sensors are much more reliable.

[Jason Beam]

It is usually just an inductive coupling to determine if current is flowing in the wire so there is no direct tap of the wire. Recall that current flow in a conductor produces a magnetic field around the wire. A piece of ferrite material around the wire will pick this field up thus creating a current and this current may then be sensed.

Aha!

That's much more logical ... I always forget about magnets. I seem to have a mental magnetic blockage.

[Tom Veatch]

.... Today's Rockler prices (illustratively) show $5 for an ABS manual gate and $13.5 for an automated gate (package of 3, $40)...

Steve, after seeing this, I was ready to write my check for half a dozen blast gates. However, looking at them on the Rockler site, I see that the "automated" part only turns the DC on and off when the blast gate is manually operated. Since they still require manual manipulation of the gate, I don't believe they would satisy the OP's (or my) concern. Shucks!

Haven't looked in a while, but the last time I did, the best prices I could find on an automatic actuation blast gate for my system (6" duct) was in the neighborhood of $300/gate (IIRC). :(

I see where Grizzly's website is listing the "old style" Ecogate type 4" gates for about $50 each. That would be doable, but they don't show the 6" gates. Amazon has the old style Ecogate marked as "unavailable from manufacturer". I guess Ecogate has converted production to the new style. Wonder what that does to the price/gate.

[David DeCristoforo]

Call the EcoGate guy. He is very helpful and can answer any questions. I can tell you this though... the blast gates are only part of the system. You also need the control box and the sensors. Otherwise, you don't have an automated system. I do know that the "starter kit" which includes everything you need to set up a fully automated system with four machines (expandable) is around $400.

[Jim O'Dell]

Jerome, I've even read where someone used compressed air to run air solenoids to operate the blast gates, so electrical solenoids would work too. Nothing wrong with that idea. I just read the original post as saying he didn't want to do electric, so I was thinking of something low tech. ;) Jim.