Sensing dust level in dust collection bin

I have an opaque 5 gallon steel drum beneath a ClearVue Mini cyclone that I use for dust collection for my small router that has worked well for several months. Today, I forgot to empty the bin so overflow went to my shop vacuum forcing me to replace its bag. In addition, I've emptied the 5 gallon drum many times when it was only partially full. Sure would be nice to have a dust level sensor in the drum. (BTW don't want to get a larger drum because it won't fit into my enclosure.)

Oneida sells a somewhat pricey solution at $148. I wonder if anyone has come up with a DIY solution.

Here's a link to what Oneida sells: http://www.oneida-air.com/pdf/Dust%2...eet%202012.pdf

Here's a photo:

Maybe a weight sensor? Any optical solution (even an infrared one) seems like it would be subject to false readings because of dust over the sensor.

You could even try just a simple bathroom scale or something under the drum.

Our large unit at work has a small acrylic window at the top...when I see the chips swirling past the window I know its time to dump it....




...not as cool as a digital readout tho :).

semi-transparent bucket? Even a regular 5 gal bucket I think you can see the level if you use a flashlight held up against it.

How about a series of vertical slots down the side of your barrel with clear acrylic glued over the slots? Then you could see what the dust level is thru the acrylic covered slots.

Don

Put a large washer on a stick and drop it in the bucket from the top. You could mark it on where you want to empty it. Just have it pulled up and when you want to check just drop it down to see how full it is.

I am impressed that an IR type sensor could work with a dust system. Perhaps the IR lets it see through the cloud of dust somehow.

I probably would have suggested using an ultra sonic setup, as those will work even with foam on top of liquids.

If your container is opaque (which it is) then you could have a cadmium photocell(Or ultrasonic sensor pointing down) near the top of the barrel that point towards the lid of your container. Then on the lid you'd have a few smaller LEDs.
When the resistance in the sensor decreases from being covered in dust and not being (partially) exposed to the light then the resistance in the sensor would go down. So you'd need to find a schematic for something that can turn say a buzzer off when the resistance is at a certain level, that can be tuned a bit with say potentiometer.
That or spend under $25, then buy an arduino clone, photocell, and a piezo speaker.
Then you could just write a quick sketch, mess with the amount of resistance/voltage needed to trigger the sensor, and the time needed at the level to trigger it to avoid false alarms.

Thanks for your help.

Cutting a window into the 5 gallon steel bin is a good idea and I'll do that soon. But since the bin is generally out of sight (behind and beneath my machine), I think a remote sensing system will be helpful too. I only found a couple of happy "Dust Sentry" users online but went ahead anyway and ordered it from Oneida.

I'll post my experience with it in a few weeks.

Along the lines of what jm82792 was suggesting, Parallax sells a small 'Ping' sensor that is really a rangefinder, and it easily connects to any microcontroller.

PING))) Ultrasonic Distance Sensor

It works from 2cm to 3m, and it may even be able to detect the dust when the vac is running. I suspect that it would be less sensitive to powder contamination than an optical sensor.

Cheers!

Ultrasonic is very poor on something fluffy or energy absorbent, I think it would not work well.

I remember a similar thread somewere and someone suggested a simple light bulb type source on one side, and a simple light sensor on the other side. That will tolerate most swirling airborne dust pretty well, but finally when the sensor is buried deep enough in dust it will be "fully dark" and trigger the alarm.

Quote:

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Originally Posted by RomanLini

Ultrasonic is very poor on something fluffy or energy absorbent, I think it would not work well.

I remember a similar thread somewere and someone suggested a simple light bulb type source on one side, and a simple light sensor on the other side. That will tolerate most swirling airborne dust pretty well, but finally when the sensor is buried deep enough in dust it will be "fully dark" and trigger the alarm.

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Sounds like the easiest option.
You could mount the sensor on the underside of the lid and an Led (as doesn't produce heat to speak of) on the side wall at the level you want. Dust gets above that level and completely covers the led and the sensor trips.

Quote:

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Originally Posted by pippin88

Sounds like the easiest option.
You could mount the sensor on the underside of the lid and an Led (as doesn't produce heat to speak of) on the side wall at the level you want. Dust gets above that level and completely covers the led and the sensor trips.

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Thanks for the great idea! I think that I can omit the LED by cutting a window in the side of the dust barrel to view the dust level. I could then mount a sensitive light detecter in the barrel lid to determine when the window is blocked by dust. For this to work, I'll need to replace the transparent (plastic) ClearView Mini cyclone with an opaque (steel) dust deputy cyclone.

Since I already ordered it, I'm going to try Oneida's "Dust Sentry" first.

Cut three 2" holes in my 5 gallon drum. (filed down sharp edges)

Prior to doing that I bent some 1/4" acrylic over the drum. (this was easier that I thought it would be... just covered a cookie sheet with aluminum foil. Placed the acrylic on two wood blocks. Heated in my electric oven set to a calibrated 270 degrees until soft. then pressed the plastic over the drum to make the exact shape. wore work gloves and used wet towels to speed cooling of the plastic. the plastic did not burn or smell. SWMBO had no objections to this project done in the kitchen!)

Glued the acrylic to the drum using silicone seal. Used tooth picks (removed later) so that the seal would be fairly thick.

Last photo shows first test ... barrel is a little more than half full ... seems to be working well.

photos:

I found that my dust collection system is really quite handy. Even though I have a vacuum outlet in the front of my router, I became frustrated when I needed the vacuum in another part of my shop.

I was inspired by a photo from Oneida's website showing their dust deputy attached to a 10 gallon steel drum installed in a cart. Here's a photo:
Attachment 181231

I really didn't want to use an exposed (fragile) plastic ClearVue cyclone so I upgraded to a steel Dust Deputy. There was no reason to use only a five gallon drum so I upgraded to ten gallons. I also didn't want to drag an electrical cord and vacuum hoses around the shop.

Here are some photos of what I came up with:
Attachment 181232Attachment 181233Attachment 181234Attachment 181235

The first two pictures show the front and back of the cart. The third picture shows the electrical and vacuum connections inside the cart. The third photo shows the electrical and vacuum connections between the cart and my router.

The cart is on two wheels so it is moved around like a dolly. (I think I'll replace the wheels with larger ones because the bottom corner catches a small rug I have in my workshop.)
All wires and hoses are contained in the unit so it can be more easily moved to my router and other places in my shop.
I used antistatic hoses and antistatic couplings (I filed down the powder coated Dust Deputy to make an electrical connection)

Attachment 181237Attachment 181236Attachment 181238Attachment 181239

The 10 gallon drum that I got from Oneida used a stiff clamp to secure the lid. My old 5 gallon drum uses a bolt on clamp which I found easy to use with my battery powered drill and adapters which I store in the cart.

I haven't cut a window into my drum yet. Since it's now 10 gallons, that may not be necessary.