Piggyback a Dust Collector on Your Shop Vac





Introduction: Piggyback a Dust Collector on Your Shop Vac

About: It's said that to perfect a skill takes about 10,000 hours of work and study. If that's the case I've got around 9,000 hours to go. But, like they say, it's not the destination but the journey.

As all woodworkers know, sawdust will clog up a shop vac's filter very quickly. Reduced suction means less sawdust is captured, creating a more dirty and unhealthy work environment. An easy fix is to add a cyclone dust collector to your shop vac. However, that means one more thing to drag around and set up each time you use your power tools. A shop vac caddy built to hold the dust collector solves this problem. I made this caddy for my Ridgid shop vac and an Oneida dust deputy, one of the most popular and affordable units available. If you own a vacuum that isn't well suited for this instructable, use the concept as a template and modify as needed for your equipment.

Step 1: Who Can Use This Caddy?

What brand of Shop Vac do you have?

My Ridgid shop vac, which is the brand sold by Home Depot, is probably about ten years old. So, when I decided to write this instructable I stopped in the store to see if the design had changed over the years. The current Ridgid 6 and 9 gallon vacs have retained the same flat, downward sloping top as my vacuum, so this instructable should easily work with those units.

I also checked out the Shop Vac brand of vacuums at another store. They utilize a bubble shaped top so you will need to get creative when designing a caddy for this brand.

Check out other designs and options online

The good news is you can find a wealth of different ideas and designs online. If this instructable doesn't fit the bill or won't work with your shop vac, that's the place to go.

Note: The Oneida dust deputy can be bolted to the side of any shop vac with hardware that is included with the unit. This is perhaps the easiest option but one that just didn't meet my needs.

Step 2: Build This Caddy in Two Simple Steps

There are only two main steps to building this caddy:

1) Build a box to hold the dust collector and

2) Mount the box to a shell that rests on top of the vacuum


I used 3/4" MDF for the shell and 1/2" MDF for the box, however wood is always a fine choice as well.

Building the Box

If you are using an Oneida dust deputy it's important to note that the bucket is tapered - smaller at the bottom than at the top. For this reason you want the bottom of the box to be slightly larger than the bottom of the bucket. With a properly sized box the sides only need to be about three inches high to provide a good fit and hold the bucket securely. The above photos illustrate the process.

Making the Shell

The shell sits on the top of the vacuum and is nothing more than two long support legs, one on each side of the motor housing. The legs are held together by small front and rear braces, with the majority of rigidity and strength gained when nailing (or screwing) the box to the shell.

Step 3: Making the Shell

As previously mentioned, the top of a Ridgid shop vac, while flat, slopes at a downward angle from the back to the front. Since we need the caddy to be level when sitting on the vacuum this requires cutting the legs with a taper that matches the slope of the vacuum's top.

Photos #2 & #3 show how I calculated the slope of the legs (FYI - make sure the vacuum is on a level surface). In my case I determined that the front dimension of each leg should by approximately 1 1/8" greater than the rear dimension. However, after cutting the leg it wasn't quite level when placed in position on the vacuum. For this reason I would recommend cutting a few test pieces from scrap lumber to verify you get things right before using your good material. I fixed the legs by cutting shims and gluing them to the legs (still not perfect but acceptable).

Anyone who knows how to more accurately calculate an angle such as this please share your knowledge via the comments!

Photos #3, #4 and #5

Photo #3 shows how to mark out the leg on your board. Next, place the angle line of the leg along the edge of a guide board and tack the leg to the guide board (photo #4). Note:the fence should be set at a distance from the blade that is equal to the width of the guide board. When you run the guide board through the saw the angle will be cut while the guide board is left untouched (photo #5).

Step 4: Mount the Box to the Shell

These photos show how the box is mounted on the shell. A few things worth taking notice of are:

Photo #2 shows the unit from the rear. If you look closely notice that I added a rail at the top of each leg to better support the box and give me a larger nailing footprint. You can also see the brace (mentioned previously) at the bottom of the back.

Photo #3 show the front brace at the top of the legs, just under the box.

Photos #2 & #3 show a 3 inch square hose holder I added to the side of the box to keep the hose under control and out of the way.

Step 5: Time to Make Some Sawdust!

Once you've finished making your caddy just roll your shop vac in place, hook up the exhaust hose from your saw to the dust collector and start making sawdust. The money you save replacing vacuum filters will help pay for your dust collector in short order. And, since the caddy can be made out of any extra material you have laying around, it may end up costing you no more than a little of your time.

Happy Woodworking!



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    18 Discussions

    KentM your projects are elegant and instructables are clear; bravo! You must be an engineer of some sort. The PiggyVac would be viable as a cottage industry for you if you vacuum formed it from ABS or polycarbonate. You'd have a great time making the forms and jigs out of wood or MDF, and I'm sure could figure out a universal mounting system. Then everyone could enjoy better dust collection easily. Myself I want the Dust Deputy but until I get one have done all right by just putting a white bucket between the vac and the wand. Even without a cyclone, large chips and especially water drop into the bucket and never reach the vac & filter.

    Well what about the motors exhaust port on the top of the shop vac? I have a similar rigid shop vac; mine seems to blow a lot of hot air out the top the motor. Wouldn't this design of yours block that exhaust?

    1 reply

    I've never had a problem since the unit sits slightly above the top of the vacuum. The openings in the front and back seem to allow for a reasonable amount of air circulation (in my opinion). Also, I shut off the vacuum between cuts or when changing the tool setup so the vacuum generally runs for only short periods of time.

    Love your concept, Kent. The question I have is twofold. I didn't notice that you stated how you attached the box to the top of the vacuum. It looks like it might slip off when rolling around. Also, does the unit tend to tip easily? It appears to visually be a bit unstable, especially if pulled via the hose. Thanks for your many great instructables & ideas.

    1 reply

    I sized the box to fit snugly around the raised motor housing on my Ridgid shop vac. It is very stable since the weight of the unit is centered directly over the shop vac. For a different brand of vacuum you may need to get more creative (like gluing sandpaper to the bottom of your dust collection box). I appreciate your kind words. Thanks to you too!

    I thought you would discuss your cone device. I think I missed that section totally. the rest is interesting.

    1 reply

    The cone device is a commercial product, called "Oneida dust deputy". That wasn't built as a DIYdevice.

    One thing I'd be curious to know a little more about is the grounding system you seem to have set up with the wire and washer that's touching the ground.

    1 reply

    That was recommended in the instructions that came with the dust collector. The wire connects to an adhesive backed metal tape that runs from the top of the cyclone to a screw where the cyclone attaches to the top for the bucket. Apparently to prevent static build up and minor shocks??

    Thank you for telling where you got I appreciate it!

    I thought you would discuss your cone device. I think I missed that section totally. the rest is interesting.

    1 reply

    The dust collection system used in this instructable is sold at Woodcraft, Amazon and numerous other retail or online stores. Just Google "Oneida Dust Deputy" for more information. I bought mine on sale for $79.99. I hope this helps.

    I thought you would discuss your cone device. I think I missed that section totally. the rest is interesting.


    2 years ago

    Thanks for the suggestions. I've used templates before but particularly like the idea of using a framing square on this project. If I had set the framing square at the base and measured up to the top I could have easily determined the difference between the low and high spots. Thanks again for your thoughts.

    I like to make templates for odd shaped things, or really anything with cardboard. You can get the profile with a razor knife then use a level on the top and to plumb the ends. Then you only cut good material once.
    You might even be able to use a framing square off the edges where the base and top meet, I don't have one in front of me here but just a thought.

    I like the vertical version instead of horizontal since it saves space on the floor for smaller shops.

    BTW, you missed an opportunity: Piggyvac instead of piggyback.

    1 reply

    Great play on words that could be a good product name. I may have to create a website and start selling these online!

    I have the exact same dust deputy and I can say it works extremely well. I have my vacuum setting on a two wheel dolly with the dust deputy bucket setting on top of the vacuum secured with bungee cords. l hope to build something like this instructable someday.