Dust collection barrel window?

[Joe Shinall]

Has anyone here added a plexi glass window to their dust collection barrel (separator or cyclone) to see how much dust is in the barrel?

I am about to do it to mine but was wondering how you get the plexi to curve with the barrel without cracking? Also what thickness plexi did you use? I would guess the thinner would flex better. I will be using CA glue and through bolts and silicone the crap out of it...

[Ken Krawford]

I added a window several years ago. I didn't worry about curvature much. I just sealed with silicon and fastened with a couple of screws. Just be aware that you will get "static cling" on the plexiglass so your window will give you a peek but maybe not what you might envision.

[Andy Giddings]

Joe, unless you are totally locked into the window, you might consider a level detector? There's a relatively low cost build thread here that's dead easy and very effective http://www.sawmillcreek.org/showthre...n-Level-Sensor

[Jim Becker]

Yes, I have a window in the top of my barrel...'been there for years. But I'm considering getting a sensor because having to constantly open up the closet to check the bin when I'm doing a lumber milling session can be a bit of a pain and it only takes a moment to fill too far.

[Jamie Buxton]

I built a window into my dust collector bin. Works like a champ -- no moving parts, no batteries, just does the job.
I didn't buy a barrel for the bin. I just made it from scrap plywood. It has flat sides, so adding a window was easy. It is quarter-inch plastic, screwed on in a few places, with caulk for sealing. On your barrel, I'd make the window fairly narrow -- like a couple inches -- and mostly count on the caulk to deal with the curvature issue.

[Tim Bueler]

Mine came with a window but I'm thinking of adding a level sensor. It turns out if you don't look at the window the dust collector can still overfill. The big question is am I smart enough to notice the bright red flashing strobe light?

[Andy Giddings]

Mine came with a window but I'm thinking of adding a level sensor. It turns out if you don't look at the window the dust collector can still overfill. The big question is am I smart enough to notice the bright red flashing strobe light?

Don't think you can miss it, Tim. Even when it's out of your sight line, the light is powerful enough to be noticed

[Joe Shinall]

I had thought of the sensor, but I have heard before about the sensors going off prematurely. I'll look more into that, because it will be in a different room so it would be great to not have to go in there. And height restrictions have got me only being able to use a 20 gallon barrel so when I'm surfacing, especially during cutting board runs, it's going to fill quick.

Thanks guys!

[John K Jordan]

The big question is am I smart enough to notice the bright red flashing strobe light?

The one ClearVue sells will flash a bright strobe, sound a very loud audible alarm, and turn off the dust collector. I put the cyclone in a closet for noise reduction but the controls and alarm are in the main shop.

JKJ

[Andy Giddings]

Joe, the low cost build has never gone off early in my case - I think if you look into the thread you'll see it's reliable. Also, the wire to the strobe can be any length you like by extending it

[Tim Bueler]

Don't think you can miss it, Tim. Even when it's out of your sight line, the light is powerful enough to be noticed

I was wondering about that. Good to know, thanks!

[Alan Schaffter]

I had thought of the sensor, but I have heard before about the sensors going off prematurely. I'll look more into that, because it will be in a different room so it would be great to not have to go in there. And height restrictions have got me only being able to use a 20 gallon barrel so when I'm surfacing, especially during cutting board runs, it's going to fill quick.

Thanks guys!

That is better than the opposite condition- if your alarm doesn't go off you risk having excessive dust pass through the cyclone to and clogging the filter.

Even with a window you must remember to check it. If the cost of a retail alarm is a bit much and you are not into heavy DIY, try a day-night lamppost sensor installed in your drum window or in the flex from the cyclone to the drum. Many years ago I designed such a system with off-the-shelf hardware store parts that worked well for years until I replaced it with a dedicated purpose IRLED high dust alarm. Here is a link to the SMC thread about it.

[Bob Falk]

That is better than the opposite condition- if your alarm doesn't go off you risk having excessive dust pass through the cyclone to and clogging the filter.

Even with a window you must remember to check it. If the cost of a retail alarm is a bit much and you are not into heavy DIY, try a day-night lamppost sensor installed in your drum window or in the flex from the cyclone to the drum. Many years ago I designed such a system with off-the-shelf hardware store parts that worked well for years until I replaced it with a dedicated purpose IRLED high dust alarm. Here is a link to the SMC thread about it.

Alan, don't the chips flying by interupt the light beam and trigger off the system?

[Alan Schaffter]

Alan, don't the chips flying by interupt the light beam and trigger off the system?

No, not at all- the dust moves too fast, is too fine, and not dense enough to block the light (until the level of the settled dust is high enough to totally block the light.)

Years ago, Bill Pentz reported that his early attempts to build an optical (photocell-based) system weren't successful. Being a skeptic and tinkerer, I did some testing and determined that the sensor did not receive enough illumination. When I added a supplemental light source, all was well. In a post on his website and/or here, Bill subsequently reported that quite a few folks eventually adopted my design and were quite happy with the performance (and cost <$20 vs $100 to > $200). It was really a simple, inexpensive (elegant?) solution. If you can wire a outlet, lamp, etc. you can build it. The output is a 110V (present when sensor no longer detects light) so it can be used to power almost any alarm device- simple light, flashing light, strobe, horn, or by adding a relay that has a set of normally closed contacts, it can be used to break the coil circuit on a DC power contactor, so the DC turns off. I used it like that to break the low voltage coil latching circuit on my DC contactor.

* The only gotcha, depends on the type of sensor and mounting location. Unfortunately, to prevent false alarms and flicker at dusk, many of these sensors have a built-in, fixed time delay that can range from a relatively short 2 min. all the way up to 5 min. If you mount a sensor with a really long time delay at the very top of the bin or in the flex hose connector, and are generating a lot of dust (using your planer to hog off a lot of wood per pass), dust can quickly build up to a point where in starts passing through the cyclone to the filter before the DC turns off. For that reason, I used a sensor that did not have a time delay. You need to read the package carefully. I never had a false alarm. But on the contrary, it is fail safe- the sensor reacts when there is no light- one time my DC turned off when the supplemental light source bulb burned out! (I eventually switched to an LED). That is much better than if it just stopped working!

There are tons of inexpensive replacement photocell sensors on the market. I used a "Summit Lighting CP688" from Lowes. Their current model is the S688 available from Amazon for $10. The listing doesn't mention a time delay so I don't know if it has one or not. It is easy to test. A short delay might be totally acceptable.

Black- hot (110v)
White- neutral
Red- switched power to your alarm device (hot when sensor no longer detects light)

Pretty simple, yes?

(actual item is slightly smaller than photo)

[Lee Schierer]

I am about to do it to mine but was wondering how you get the plexi to curve with the barrel without cracking?

Bending acrylic or polycarbonate is easy (polycarbonate is much stronger). It softens at about 275 degrees. You can do it in your oven for a small piece. If you make a form for the curvature you need out of wood, you can lay the form in the oven with the plastic on top and heat both at the same time. Watch through the window. When the plastic sags onto the form, turn off the oven and open the door. Let the part cool on the form. I would suggest drilling any holes you need before bending.