DIY Shop Vac Dust Collector




Introduction: DIY Shop Vac Dust Collector

 Like a lot of people, after retirement I built a woodworking shop.  I looked at the commercial dust collection systems, and did not like the look of the 4" hose laying all over the shop.  I also did not think I needed the capability of running several machines at once since it's just a hobby shop.   I decided to look at the possibility of using a smaller diameter wall mounted piping system using PVC.  My logic here was that a smaller diameter with adequate CFM resulted in higher velocity, hopefully resulting in similiar performance using one machine at a time.
I also wanted to use my existing shop-vac, knowing from experience that the 5.0(peak) HP unit was more than adequate for the machines I have, as i have used it on each, manually changing the hose.
The last requirement was it had to turn on automatically, I was getting tired of "aw crap", forgot to start shop-vac first!

With all the above, the photos pretty much explain where I went from there.  1-1/2" PVC water pipe with 1-1/2" electrical conduit wall brackets made it easy to setup.  I opted for ball valves instead of blast gates, mainly because it was going to take more work to match fittings for the blast gate.  The standard 2-1/2" vacuum hose did not quite match up to the outside diamater of the PVC, but as always, the "handyman's secret weapon" duct tape, provided the solution.  I wrapped duct tape on the PVC pipe end to the size where I could use a hair dryer to expand the vacuum hose and slide the hose over the duct tape.  When the hose cooled, it made a perfect fit.

I decided early on to use the Dust Deputy cyclone and capture most of the dust and chips before they made it to the shop-vac so that I would not have to clean so often.  The other driving factor was that this allowed me to put the shop-vac above the ceiling.  More floor space and less noise.  The unit mounted easily on the drum lid with six 1/4" metal screws(not included).   I have to say, at $40 I was buying a bit of a pig-in-a-poke, but it truly  works as advertized.  I have half filled the 30 gallon drum with sawdust and have yet to empty the shop-vac or clean the filter.

I decided to anchor the PVC pipe going through the ceiling by using a floor flange for electrical conduit and drilling a clearance hole for the PVC, then gluing the PVC in place.  I also used a pipe clamp above the ceiling on the PVC.

I looked at a few commercial current sensing products to automatically turn on the shop-vac when I started one of the machines, but the cost was about $50 per machine for the remote nodes, plus the controller itself.  I, luckily, have all 5 of the machines I use the shop-vac on, on one circuit, which simplified the automation requirements as I just had to monitor one point.

I settled on a design that did not limit the current in case I did try to run multiple machines, using an Aprilaire 51 current sensing relay that is normally used for humidifier circuits triggered from the furnace fan motor current.  It is only rated for 50 watts so I used it to drive a relay.  When I first prototyped the circuit, the relay was energizing immediately.  After a replacement current sensor gave the same result, I started experimenting with loading, and determined that although the specs said 50 watt max, it should have also said 10 watt minimum load.  The particular relay I used only draws 10ma and measures 5k ohms resistive load, so I added a 2k ohm 20 watt wirewound resistor in parallel with the relay coil to increase the load and keep the relay from a false start.

The system has been running about a month, and works to my expectations, with more than enough vacuum and velocity.  One gotcha in my system is my paper barrel.   I closed all of the valves with the shop-vac on and it imploded.  Nice ad for Shop-vac I suppose.

I'm not good at writing conclusions, or writing at all for that matter, so I end here I guess.  I'd be happy to answer any questions.


Update - 10/30/2012
I was still having trouble after 3 months with occasional false triggers from my garage door opener.  I modified the circuit by replacing the original relay with a single contact relay and replaced the 2000 ohm resistor with a 40 watt light bulb.  It has ran well since then, with no false triggers, but I have procrastinated updating this site.

I also added a wall switch directly across the Aprilaire current sensor to aid in shop cleanup.  The switch energizes the relay to start the vacuum directly, so I can connect a 20ft hose to clean the floor.


Update - 10/24/2014
I added a 25 foot hose to clean the shop floor.  Looking around the one that worked the best was a swimming pool skimmer.  I added another valve and elbow, and this hose fit the inside of the elbow with duct tape where the 2 1/2" went on the outside of the pipe.
Live right I guess.  The hose reaches everywhere in the shop, even the cobwebs in the corners, and standard attachments all fit.


Update - 12/4/2014
Replaced the small dedicated vacuum system on my mitre saw with an extension ran across the ceiling.  The $20 vac has never quite handled the air flow generated by the saw.  I left the valve on the other side of the room, true it's not quite as handy, but can I reach it easy this way and this lets me put the flexible vacuum hose high on the wall for the swivel path of the saw.  I also ran a dedicated outlet on the wall for the saw from the sensed circuit across the room for the other tools on the vacuum system.  Again, since I only use it for one tool at a time, there is plenty of capacity of both the electrical and vacuum system.




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    34 Discussions


    Question 5 months ago

    Do you feel your shop vac has enough suction to handle the length of tubing you have? I am thinking about using a 6.5 hp Craftsman and a dust deputy but concerned if it will handle it. My run will be 30-35 feet before connecting to tablesaw etc. Also I am thinking on putting vacuum in a noice preventing cabinet. Do you feel it will over heat?


    11 months ago

    I currently use the Dust Deputy atop a 5 gallon pail before going to my shop vac. I recently bought the HF 2 HP dust collector system. I really like your set-up. Would the HF be TOO MUCH power to use your type set-up with the 1 1/2" PVC and putting my DUST DEPUTY atop a 55 gallon drum? I guess what I really need to know is would 1 1/2" PVC and the DUST DEPUTY work with HF 2 HP dust collector or would I need to use larger diameter piping. and press on with building a Thien separator or baffle as some call it?.

    For a hobby wood shop, I wanted to start my shop vac with a remote. I don't do electrical and didn't want to spend a lot of time and money on this. Amazon carries now a lot of outlets with remotes, but my shopvac is 15amps, 6.5 HP. I finally found a wireless remote switch system at Harbor Freight for $20 and it's rated for 15amps. Comes with 3 separate outlets (labeled 1,2,3) and a remote with 3 buttons to operate these outlets individually. Works through walls and other obstructions.

    The Harbor Freight link won't paste here. Search for Indoor Wireless Remote System 3pc. Item 62575. I found this through a youtube video where the person went to HF and found a Stanley brand equivalent, but I had no luck finding that online or at HF so settled for the house brand.

    Anyone on this post have any input regarding DWV vs Schedule 40? Any reason one couldn't use DWV?

    nice set up by the way how many ball valves did you use

    1 reply

    I used five, one each for 6" joiner/planar, 13" surface planar, shaper, sander, & bandsaw. Would have used more if shop were bigger, since you only open one at a time.

    Awesome. Thanks so much for this. Exactly what I was looking for. While I'm comfortable with electronics, I have some old X10 outlets with a remote. I may just try that for awhile to switch on the vac. Thanks again!

    The ball valves work well as a vacuum seal, but once in a while they get stiff and hard to close completely. WD40 loosens them back up. Probably fine dust on the ball is the culprit. How do the costs compare?

    1 reply

    Thank you for responding.

    The 2" PVC pipe and fittings (elbows, wyes, couplings, etc.) seem to be less than 50% of the cost of similar components for 2.5" dust collection systems (from Rockler & similar vendors). The PVC ball valves do cost about 25% more than the "better" 2.5" blast gates (which still aren't very good). Total cost of a PVC system would be less, and the components are available at any home improvement store.

    A common complaint of the 2.5" systems is that they tend to leak, as the pieces don't fit together nearly as snug as with PVC. The 2.5" pipe is expensive and comes in 3' sections, so there are likely to be more joints to leak. (I will say that it is kind of neat to be able to see dust moving through the clear 2.5" pipe.)

    In my opinion, it appears that the advantages of PVC (stronger, seals better, easier to find parts for, less expensive, available in longer lengths) are enough that it makes sense for me to go forward with PVC.

    Thank you for writing this instructable! I am in the planning stage of building a basement workshop. I have a few pieces of the clear 2.5" pipe and fittings from a small setup that I used at my previous home and initially planned on expanding on this system. However, the more I research and think about it, it seems that using 2" PVC would be better and probably less expensive.

    How well do the ball valves work for dust collection? The commercially available 2.5" blast gates seem to be almost universally disliked, and the PVC ball valves seem like a much better option in theory. Thank you!

    Could u give some more info on the dust collecting chamber itself? What did u use to put it together are there any baffles inside?

    1 reply

    If you are referring to the barrel where the sawdust ends up, it is just a 30 gallon paper barrel with a metal lid that lifts off. There are no baffles inside at all. I suppose most people would use a metal barrel but I had this one and it is much lighter.

    If you are referring to the barrel where the sawdust ends up, it is just a 30 gallon paper barrel with a metal lid that lifts off. There are no baffles inside at all. I suppose most people would use a metal barrel but I had this one and it is much lighter.

    Really outstanding. I have never gotten around to much beyond building a DIY cyclone thing, but I have every intention of getting on it when it gets warmer...


    Most of the stuff was in my junk box. The Aprilaire 51 current sensing relay was on ebay, think $15 or so, same with the RIBU1C(ebay). I could have built cheaper by not using the heavy electrical box(Menards- don't remember the cost). But I don't think I have over $60 in it.

    Could you list the make/model/part number for the vacuum relay? I'm looking to built the automatic vacuum toggle part of this project and want to make sure I'm looking at the right parts.


    2 replies

    Sorry for the procrastination. Look over the schematic and pics again, I had updated the circuit but didn't get around to updating this website. I think the relay you want is the R1BU1C, I'm sure I got it off of ebay.

    Make that RIBU1C from Functional Devices.