Controlling the Hidden Beast

[McRabbet]

There has been considerable attention by woodworkers here and on other forums concerning Dust Collection. I recently purchased a ClearVue Cyclone (like at least five others here) and I've looked at how others have installed their units and the duct works to rid their shops from all that dangerous dust we produce. In my case, I'll be installing my 8-foot tall beast in a higher crawl space under my 800 SF shop and running 6" PVC ductwork under the floor like Alan in Little Washington. Alan and I share the challenge of controlling our cyclones from a floor away and need to know when the sawdust bin is full to avoid filling expensive filters with more than a trickle of very fine dust. Alan conceived and documented his bin sensor last year in two threads (this links to the second one and it has a link to the first). Mine is not much different, but uses some different components. Here is a schematic diagram, which I'll explain below the graphic.

Here's how it works. 230V power is fed to the 5 HP Leeson motor on the ClearVue through a Fasco H230B 2-pole contactor (common lead not shown), which is Normally Open (NO) in the Off position. 110V power is fed through a remote switch and through the Normally Closed (NC) contacts of a small "ice cube" relay (so named because of its shape and size). When the Remote transmitter closes the remote switch, power is sent to the 110V coil on the Contactor and the Blower Motor starts up and runs as long as coil is energized. OK so far or are you :SLEEP:?? Over to the right side of the diagram, you'll see Alan's small light and photo eye (about $13 at Lowe's) that are placed in the bottom end of the cyclone, just above the bin. When the light beam is blocked by sawdust and chip accumulation -- i.e., the bin is full -- the Red line is energized and it activates the coil in the Ice Cube relay, opening the NC contacts and sending the 110V power to an indicator bulb in my shop space above. And, because the 230V Contactor no longer is energized, 230V power does not get to the Blower Motor and it shuts down!!:jiggy: The switch by the candelabra is used when emptying the bin -- this keeps the photo eye dark and it keeps the blower from restarting prematurely (if I forget to toggle the remote control transmitter off, that is!)

I'm currently in discussions with Jim Murphy (Fernhollowman) and Alan Schaffter (Alan in Little Washington) about improvements in our control circuits beyond this design -- We are looking at options to have a Momentary Contact Switch at each power tool to turn the DC On or Off and delay timers to protect the big motors from overheating due to excessive On/Off cycles (spinning up a big impeller pulls heavy amperage and heat is generated and retained if done too often).

I've built a mock-up and will post pictures when I can -- I have shoulder surgery this next week and so I'm doing arm-chair work these days and for several weeks to come...:wmad:.

By the way -- this will work on about any dust collector with a bin -- you may need a brighter lamp for a big bag unit, but it is ideal for any cyclone. I can provide links for any of the parts for this -- aside from the remote switch which was about $25 at Ames Hardware, the other parts are less than $50, including a good enclosure.

 

[toolferone]

Okay, I really need to build this soon. My cyclone is in a closet off the back of my closet. I have over filled it several times. I will need to mount my eye down on the bin as I have about 4' of pipe from the bottom of the cyclone to the bin and I don't want the pipe filling up with sawdust before the eye catches it. Do you see any problems with that?

 

[Jim Murphy]

By the way -- this will work on about any dust collector with a bin -- you may need a brighter lamp for a big bag unit, but it is ideal for any cyclone. I can provide links for any of the parts for this -- aside from the remote switch which was about $25 at Ames Hardware, the other parts are less than $50, including a good enclosure.

Rob,

As we progress, I suggest that since you have started giving part numbers, we make this easier for others by specifying the terminal connections the various relays need. I had to mind-meld with AlanILW to begin to understand the wiring diagram for the delay relay. It would be much easier for others if we said you can buy a SuperDuper Model XYZ delay relay from InternetElectronics (with url provided) for about $28 plus shipping. You then wire a 120v black lead to terminal 1, jumper it to terminal 2, and connect switch Z to terminals 5 and 6. That sort of thing. OR, on the schematic, provide terminal numbers at each component. OR, both.

After all, we're all here to help, right?

 

[McRabbet]

The only issue I can think of is false triggering from a heavy slug of sawdust if you are using a floor sweep. If your pipe up from the bin to the base of the cyclone was clear (even if is is clear flex duct), then you could see if there is a clear spiral of dust traveleing down to the bin as there is on a ClearVue. That way, you could place the sensor/light across a segment that remains "clearer" during normal use. Another option is to use a larger/brighter bulb, but I'll warn you that 20W - 40W - 60W chandelier candelabra bulbs don't last very long and they generate lots of heat -- and do not operate them any way except base down (doesn't apply to the 7W ones). Hope this helps.

 

[McRabbet]

OK -- here's a parts list for key components of my schematic and then the wiring details:

1) Allen Bradley 700-HA32A1 Relay: Try http://tinyurl.com/3y6yjd $5-11 + shipping
2) Allen Bradley 700-HN125 Base Socket:http://tinyurl.com/2qj9ro $3.89 + shipping
3) Fasco H230B 2-pole contactor: http://tinyurl.com/2gk4bm $10.18 plus shipping
4) Carlon HW2190 Remote Control: http://tinyurl.com/yu3o3e $24.99 + Tax (Cary Ace Hdwe)
5) Universal Photoeye CP688: http://tinyurl.com/373w5p $12.93 at Home Depot or Lowes (Item 70551 = $12.96) + tax
6) Candelabra Socket: http://tinyurl.com/2dqmwc $2.98 at Lowes (in drawers near fuses).
7) Control Enclosure: http://tinyurl.com/2fh7zg $11.18 at Lowes.

I've also bought Handy boxes for the bin sensor and candelabra, light socket for the shop light and miscellaneous bushings, wire nuts, lug connectors etc. I bought a 6-foot Green outdoor rated light duty power cord and cut off the receptacle end (preserving the male plug) to connect the remote control to the Controls Enclosure.

Drill 10-32 clearance holes in the controls enclosure to mount the H230B and Allen-Bradley Base socket inside the bottom of the enclosure. Drill appropriate holes for 1/2" Romex bushings in left, right and lower sides opposite connections on the two components to feed 5 wires into the enclosure. Then make connections on the Controls parts as numbered:

H230B: Step 1: #10 Romex Black and White wires with Yellow (#10) female spade disconnects slide onto male spade connectors on Contactor end -- repeat on opposite side for 230V line to blower motor. Use wire nut to connect bare common wire (keeping it clear of other connectors). Step 2: Run a single Black #14 wire (I stripped some out of #14 Romex) from pin 4 of the base socket to either coil connector on H230B. Step 3: Run a White #14 wire from pin 5 of Base Socket to the other coil connector of H230B.

700-HA32A1/Base Socket: Step 1: Run the cut end of the Green cord that plugs into the Remote outlet through a bushing into the Controls Enclosure (left side) after stripping 4" of jacket and 1/2" of jacket on the 3 wires. Step 2: Connect White wire to Pin 8 and Black wire to pin 1 of the Base Socket (I used open end screw connectors crimped to the wires). Step 3: Run a piece of #14 Romex wire from shop Indicator light through bushing on opposite side of enclosure, strip as above and connect Black wire to pin 3 and White wire to pin 6. Step 4: Run a piece of 3-wire #14 Romex from box with photoeye at cyclone to controls enclosure, strip each end as above and cut off the Black wire. Feed remainder through bushing and connect Red wire to pin 2 and White wire to pin 7. Step 5: Connect the ground wires in this paragraph together with a wire nut.

I used a second small extension cord to feed the 7-watt candelabra, again cutting off the receptacle end. Black or hot side connects through a bushing in the handy box to a small toggle switch (in the cover plate)and other side of switch is connected to the candelabra base Black lead. The same incoming Hot or Black lead from the power cord is also connected to the Black side of a #14 Romex line run to the photoeye handy box. White leads of incoming power line and candelabra are connected together to White Romex wire with a wire nut. At the photoeye handy box, the three White leads (photoeye, and two Romex wires) are wired-nutted together, Black from Candelabra wire connects to photoeye Black and Red from Photoeye connects to the Red wire in the #14 3-wire Romex going to Controls Enclosure (remember to cut off the black lead in this wire). And be sure to connect the ground wires to the handy boxes and to incoming ground wires.

That's it. Questions?? :laugh:

 

[Alan in Little Washington]

Somehow I missed this thread. Since the original thread got a little geeky and long, I have been corresponding with Jim and Rob via e-mail. They have done a great job with photo documentation, identifying parts, and drawing schematics.

One minor change to Rob's schematic I suggested is to put a (the) safety switch between the black are red sensor wires, bypassing the sensor. This will keep the Allen Bradley 700 relay energized and and ensure the blower won't turn on when emptying the dust bin. The switch adjacent to the candelabra light will turn off the light, but it might be possible for stray ambient light to (de)activate the sensor and allow the blower to run if the main switch/remote is inadvertently left on.

As you may know, my DC system does not use a remote- I figured that I would put it down and not be able to find it :BangHead: like scores of missing pencils or the occasional tool, but I can start my system from one of many button locations and turn it off from that or any other location. There are a number of methods to achieve this. In addition to my method you can use relatively inexpensive (pulse sequencing) relay that will allow you to fully control your DC from any location using only one momentary SPST push button at each location. One push of any button will turn the system on, while the next push of any button will turn the system off. When I get around to it I will post these schematics and parts lists.

I am also working on an inexpensive homebuilt electro-pneumatic automatic blast gate and will post pictures when I achieve a reliable version.

 

[Alan in Little Washington]

The only issue I can think of is false triggering from a heavy slug of sawdust if you are using a floor sweep. If your pipe up from the bin to the base of the cyclone was clear (even if is is clear flex duct), then you could see if there is a clear spiral of dust traveleing down to the bin as there is on a ClearVue. That way, you could place the sensor/light across a segment that remains "clearer" during normal use. Another option is to use a larger/brighter bulb, but I'll warn you that 20W - 40W - 60W chandelier candelabra bulbs don't last very long and they generate lots of heat -- and do not operate them any way except base down (doesn't apply to the 7W ones). Hope this helps.

After a year using my dust sensor, I have had maybe two false shutdowns using a 7W bulb- once when vacuuming up a pile of MDF dust, the other when a bulb burned out. The dust is just moving too fast and is spread out no longer in a "slug". Also, the cyclonic flow actually continues down into the dust bin and keeps the sensor clean. A future upgrade might be if a suitable LED can be found to replace the candelabra light.

 

[Alan in Little Washington]

Okay, I really need to build this soon. My cyclone is in a closet off the back of my closet. I have over filled it several times. I will need to mount my eye down on the bin as I have about 4' of pipe from the bottom of the cyclone to the bin and I don't want the pipe filling up with sawdust before the eye catches it. Do you see any problems with that?

Tom- sorry I am slow posting to this, but the sensor should really be mounted just above the bin where the cyclonic air flow will keep it clean. I believe previous attempts at optical dust sensors failed because they tried to put the sensor in the bin and/or did not use a supplemental light source. The dust is carrying a lot of static charge and will stick to and obscure the sensor and bulb, long before the bin is full.

Filling up the tube a little is no problem if there is a few inches of duct extending into the bin. In operation the dust will fill the bin until it reaches the duct extension, then, unlike water, will fill the extension only. The extension gives you free space at the top of the bin where the dust in the duct can drain. This also makes it easier to carry and empty the bin. Here is the sketch of this concept from my thread from last year.

 

[junquecol]

Alan, why not use a SSAC current sensor in the panel box to control the DC. When a machine turns on, DC comes on. By adding a delay on off timer, DC can be made to run after machine shut down. This allows for clearing the pipes. You only need to run one leg of a 220 circuit through the sensor. It can handle about (6) #12 wires through the coil. A sensor that is controlled by the blast gates opening/ closing, means that the gates will have to be operated before and after each cut. The only remote in my shop is for the hanging air cleaner.

 

[McRabbet]

Bruce, I considered using current sensor circuitry for mine as well -- there was a very good version published in Woodwork magazine a year or so ago. I've found that I try to leave my DC on (since it is under my shop, the noise is not troublesome) so that as I move from process to process, I only need to adjust a blast gate here or there. I keep my remote control transmitter pinned to my shop apron on an old Orvis "zinger", so it is always handy. If I do need to shut it down, I can at any time. I'm also concerned with motor overheating in cases where the blower has been cycled on and off too frequently and it hasn't had time to cool off a bit. Lets face it, a 15" impeller made of 3/16" steel has some weight that the motor has to spin up quickly and that generate heat.

I have revised my Controls Circuit schematic incorporating a suggestion that Alan made -- I added a toggle switch near the photo eye to insure that the relay coil remains energized when I'm emptying the bin after an automatic shut off. If the remote was left closed and light gets to the photo eye, it would re-start prematurely. This version also shows the pin connections on the small control relay. I've made a mock-up of the circuitry on a piece of plywood and it all works fine.

 

[junquecol]

I think this over heating from frequent starts thing is a crock. Any respectable manufacturer will design his fan / motor assembly for cycling. Think about how many times a saw, or air compressor starts per hour. In over five years of operation, my Cincinnatti Fan unit hasn't complained one bit. If it did over heat, the thermal over load would shut it down.

 

[ptt49er]

A future upgrade might be if a suitable LED can be found to replace the candelabra light.

You're LED idea has my brain working...

You could use one of your old cell phone chargers that puts out a steady 12V DC to power a cluster of small LED's.

It wouldn't be too difficult to wire them up....

ANOTHER project for me to try, I'll let ya know how it goes ;-)

 

[Jim Murphy]

I think this over heating from frequent starts thing is a crock. Any respectable manufacturer will design his fan / motor assembly for cycling. Think about how many times a saw, or air compressor starts per hour. In over five years of operation, my Cincinnatti Fan unit hasn't complained one bit. If it did over heat, the thermal over load would shut it down.

Go here: http://www.ralphpill.com/calculators.shtml

Scroll down midway and find a table based on NEMA std. 10-MG which allow calculation of the MAX starts/hour for larger motors. Both NEMA and the individual motor mfrs. provide a MAX starts per hour. The 5HP Leeson in the CV system is rated at 6 starts per hour. As installed, the only motor I cannot access and remove singlehandedly is the DC motor. Why tempt fate?

 

[PurpleThumb]

Good Luck on the Pyranees neccessitated surgery if I don't talk to you before. I'm through the "pain" to the "sore "part of mine.
Thanks for the diagram and the sharing of info by you, Alan, and so many others. This truly is a GREAT site.

 

[Joe Scharle]

I trust that when you guys get this design finalized that you'll put in into a download area. When I finally get around to setting a DC up, I'll probably not be able to find this thread.
Good work & thx,
Joe

 

[McRabbet]

Go here: http://www.ralphpill.com/calculators.shtml

Scroll down midway and find a table based on NEMA std. 10-MG which allow calculation of the MAX starts/hour for larger motors. Both NEMA and the individual motor mfrs. provide a MAX starts per hour. The 5HP Leeson in the CV system is rated at 6 starts per hour. As installed, the only motor I cannot access and remove singlehandedly is the DC motor. Why tempt fate?

I agree, Jim -- In my case, I'd rather not go outside my shop on the east side of my house, traverse the full length of the back of my house through my natural (i.e., thorn-infested) area to the crawl space door and then come back 60 feet to climb up a ladder to press the thermal overload button -- it will be enough trouble making this trek to empty the bin when it fills! That is why I'm also trying to design a pre-separator that will handle the chip outputs of my planer and jointer to reduce the CV to true dust collection. I plan to avoid multiple on/off motor cycling.

 

[McRabbet]

Good Luck on the Pyrenees necessitated surgery if I don't talk to you before. I'm through the "pain" to the "sore "part of mine.
Thanks for the diagram and the sharing of info by you, Alan, and so many others. This truly is a GREAT site.

Jerry,

I've been meaning to call you, but I've been busy with our WNCWA meeting this past Saturday, tinkering on DC stuff and getting ready for the rotator cuff surgery I'm having -- I'm glad you are through the hardest part following the knee replacement and will be diligent with your PT so you can get back to full throttle soon. My shoulder procedure is much less invasive, but I'll have similar phases -- mine is outpatient because it is arthroscopic (LOML wondered when they'll install a "drive up" window at the hospital!!) and they send me home the same day.

I uploaded the pictures I took of your ClearVue installation to my Dust Collection Album and will post a few pics later for everyone's benefit.

Glad you're feeling better! :yes:

 

[McRabbet]

I trust that when you guys get this design finalized that you'll put in into a download area. When I finally get around to setting a DC up, I'll probably not be able to find this thread.
Good work & thx,
Joe

Count on it!

 

[Alan in Little Washington]

I finally got around to drawing up my DC control circuit. Here is my CAD (crayon alternative drawing) :-D:-D:-D:

My circuit is similar to Rob's but uses multiple pushbutton control stations vs a remote- a personal choice. Here are the differences and features-

• A 3 pole contactor with 24V coil. Extra set of contacts is used for a "latching circuit."
• Full "START" and "STOP" using any of an unlimited set of spring loaded, momentary contact, pushbuttons located throughout the shop. This function allows starting the DC from any station and stopping it from that or any other location, and visa versa.
• This schematic shows only one set of "START"/"STOP" pushbuttons, however any number can be added and wired the same as the set shown.
• No remote- It could be added (with some difficulty, however)
• The "additional START" represents a normally open (N.O.) micro-switch or magnetic reed switch mounted on a blast gate. Having a blast gate start the DC is desired, but I do not want a blast gate to turn it off due to motor cycling issues. I could incorporate a "delay on off" relay but that would make the circuit more complex especially since I want the buttons and high dust circuit to cause immediate shut down.
• The SPST relay depicted as part of the high dust circuit can be any 110V relay (e.g. DPDT) with at least one set of normally closed (N.C.) contacts.
• A high dust condition breaks the "latching circuit" and turns off the blower. The blower will not restart without pushing a start button (or opening a blast gate if I equip the gates with start switches)

Operational description:

(The schematic illustrates an "OFF" circuit state.)

• To start - momentarily press any START pushbutton.
• This action completes a 24V circuit which temporarily energizes the main contactor coil.
• The contactor contacts close and provide 220V to the DC motor through the top two sets of contacts.
• The bottom set of contacts provides 24V to the contactor coil (via the latching circuit) and keep it self-energized. (this function is identical to the magnetic starters on most WW machines)
• Momentarily pressing any STOP pushbutton, breaks the latching circuit, which de-energizes the main contactor, cutting power to the DC motor.
• When a high dust condition breaks the light beam to the sensor, the sensor provides 110V, via the "RED" lead, to the coil of the relay. A set of N.C.contacts in the relay open and break the "latching circuit" so the DC turns off. (Even if the high dust condition is resolved while dumping the bin, the DC will not automatically restart; a start button must be pushed.

Many different circuits can be used to control a DC and the choice depends on your needs and how much you want to spend. One alternative START/STOP circuit uses only two wires and a single button at each control station to provide full START/STOP control from each of any number of locations, using a "Pulse Sequencing" relay. It is easy to wire. I won't even get into using a PLC (programmable logic controller) base system similar to what is used by the EcoGate and similar systems.

Since there has been so much interest lately in DC matters, maybe Steve could add a "Dust Control" forum to NCWW.

 

[McRabbet]

Control Circuit with On/Off Service Switch

Well, I hope this is the last revision I need to make to my bin sensor circuit. One of the concerns that I had is premature restarts to the dust collector during servicing of a filled bin. Since my design uses a remote transmitter to control the 30 Amp DC Contactor, if it is not shut off, then the unit could restart easily. Alan Schaffter suggested a latching circuit modification, but I have been concerned about burning out the photoeye with his design (conjecture on my part because I didn't test it -- but I think this new plan is just as good). Here is the revised circuit:

The wiring next to the Photoeye has been altered with the addition of a Single Pole, Double Throw (SPDT) switch with a center "Off" position. In the position shown here, the sensor is in normal operating position; when the bin fills, light is blocked from the photoeye and the relay shutting down the DC is tripped along the Red wires and the Shop Indicator Light is turned on. When servicing the full bin, the switch is moved to the Down position, feeding 110V from the hot side of the circuit to the same relay, keeping the DC off and the photoeye is disconnected. In the middle position, the bin sensor is deactivated all together and only the remote control operates the DC. Obviously, you don't want to leave it in this position or continued dust collection could lead to clogging filters.

Jim, now you know what I planned with that "Monster" switch! :rotflm: For the rest of the readers, the SPDT switch is a very petite toggle switch measuring .34" x .25" x .32" and with a .4" long toggle!