Piggyback a Dust Collector on Your Shop Vac

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.

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.

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

Materials:

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.

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).

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.

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!