Rebuilding My Dust Collector Homemade Machines & Jigs

When I bought my dust collector, I thought it would be perfect for the kind of work I do in my shop. It was portable and I could just move it where needed and quickly connect it to the tool I would be using. As it turns out, that was actually a lot more inconvenient than I thought, especially in a small shop with limited walking space and always a bunch of stuff on the floor. About the only thing I regularly connected it to was my thickness planer. Mostly I just used it to vacuum the floor, during my all too infrequent clean-up sessions.
The model I bought was inexpensive and the specifications say it’s capable of 350cfm, which is probably a little low for the kind of dust a table saw can pump out. When cutting dusty material like MDF, I would often connect it to my table saw to let it catch the fine dust. It worked well for that, drastically reducing the amount that got into the air.
Since I have so many shop organization projects happening, I decided to rebuild the dust collector and make it stationary. The table saw and miter saw are the two most used tools in my shop, so I figured I could put it close to those and connect it directly to both. The idea is to catch the fine dust that these two tools produce, while leaving the heavier dust to the passive collection systems that are already in place. Along with that, it can be switched on to clean the air in the shop while I’m doing some other operation, like sanding. Also, by adding a port for the 2-1/2″ hose, I can still use it to vacuum the shop floor.
I have to say that I wasn’t 100% certain that doing this would be successful, so I rushed through it without much planning, just to see if it would work as I thought it would. Of course, I made some mistakes that could have been avoided if I had
spent a bit more time at the drawing board. In the end, it turned out better than I expected. Even with building it on the fly, I don’t know that I could have done much better, performance wise.

One of the biggest problems with the type of dust collector that I had is that everything that gets sucked in has to pass the impeller. That’s fine, if all that goes in is saw dust.
As I was using mine mainly to clean up, it would suck in all kinds of things, including this countersink:

make a dust collector better impeller

That’s where it was! I found that while taking the unit apart to do this rebuild.
This kind of abuse takes its toll on the impeller and housing, which is quite dented.

To get started, the first thing I have to do is adapt the metal centre section of the collector (the part where the filter bag will attach) so that a cabinet can be built around it. To do this, I cut two pieces of 3/4″ plywood into equal parts, then put them together and drew a circle that is equal to the outside diameter of the centre section:

make a dust collector better

I then cut out each half on the band saw and fitted around the centre section:

make a dust collector better
make a dust collector better

The collar is a good, tight fit.

Polyurethane construction adhesive is used to attach the two halves. It is probably the best glue to use for this, since it adheres to both wood and metal and can easily fill any gap between the two:

make a dust collector better
make a dust collector better

I’ve cut blocks to prop the collar up high enough to get the filter bag back on afterwards. Clamps hold it until the glue dries.

make a dust collector better

To make sure this junction is as airtight as possible, I used more of the construction adhesive to caulk the joint all the way around.
Even though I wasn’t sure that this new configuration for the collector would work well, I still took the time to make sure that all of the things that should be done, were done.

The next part goes at the bottom of the centre section and divides it from the collection bin below. It is a typical Thien baffle with a slot cut three quarters of the way around to let the dust drop through to the collection bin:

make a dust collector better
make a dust collector better

To attach it, more construction adhesive is applied to the rim of the centre section.

The glue needs several hours to cure, but before leaving it, I make sure the two parts are lined up correctly.
I then left it to dry overnight.

make a dust collector better

The next day, I put the filter bag on and found that the collar was not quite big enough. The clasp sticks out past it:

make a dust collector better

Lack of a detailed plan and trying to make this as slim as possible are to blame for this mistake.

To fix it, I added solid wood strips to the edge:

make a dust collector better
make a dust collector better

With that little problem solved, I could move on to assembling the collector cabinet. The sides and back are 1/2″ plywood, glued and screwed to the centre section. Here I’ve attached one of the side panels.

Then the other side was put on. This one had to be cut for the inlet pipe:

make a dust collector better new housing

The back is put on. Overall, a fairly simple design to build, with no complex joinery – just butt joints, glued and nailed:

make a dust collector better
make a dust collector better

I used 3/4″ plywood for the top and bottom.

With the bulk of the cabinet done, I had to figure out how to mount the blower. I decided to keep it simple and just let it sit up on top of the cabinet with the inlet pipe coming down through to hold it in place. To make this as airtight as possible, I added a ring of 3/4″ plywood to the blower housing that provides a flat mating surface:

make a dust collector better

I used my compact compass to draw the right size hole:

make a dust collector better compass draws circle
make a dust collector better

A bead of construction adhesive seals and fixes the ring to the blower housing.

make a dust collector better motor

Another 4″ hole is cut through the top of the cabinet for the inlet to come though.
At this point, there is no gasket between the ring and the top of the cabinet, since I wanted to make sure that this was going to be an effective arrangement before going much further.
If the pressure drop proved to be too large, I could always put a bigger blower unit on top, just by lifting off this one.

Time for a quick test. To seal the filter bag compartment, I just held a piece of 1/4″ plywood over the front and turned on the blower. I was pleased to see that it sucked in tight to the cabinet and stayed in place. Airflow through the inlet was strong, also, in spite of the bottom compartment being wide open:

make a dust collector better
make a dust collector better dust filter

With the blower turned off and the plywood removed, I looked to see how close the filter bag is to the sides after it was fully expanded. I could have been a bit more generous with how much space there is, but it seems to be working well and the bag is not actually touching the sides, so air can still flow reasonably well.

Next, I added cleats to attach the front panel:

make a dust collector better without gasket
make a dust collector better with gasket

I then put peel and stick foam weatherstripping around it to make an air tight seal.

The front panel is screwed in place, just tight enough to compress the weatherstrip to get a good seal:

make a dust collector better

To close the bottom compartment, I made a panel from 3/4″ plywood that is glued and nailed in place. This bottom compartment is where the dust will collect:

make a dust collector better
make a dust collector better

Another test was to vacuum up a pile of sawdust and small pieces of wood to see how well the Thien baffle works. A look inside the centre section afterwards shows it is performing very well, with nearly nothing left. I expect the few ‘crumbs’ fell back down from the filter bag, after the blower stopped.

To empty the collection bin, an access door is needed, and I cut an opening near the bottom in the front panel:

make a dust collector better

Inside is the sawdust I vacuumed up.

The door for the opening is 3/4″ plywood, fitted with cabinet door hinges and a weatherstripping gasket:

make a dust collector better door
make a dust collector better door installed

The door overlays the opening by about 3/4″ on all sides, providing a place for the weatherstripping seal.

To hold the door tightly closed, I made a simple latch using a hanger bolt, wing nut and fender washer:

make a dust collector better
make a dust collector better

When closed, the door seals tight to the front panel.

In order to conveniently empty the collection bin, I decided to lift the collector up off the floor high enough to get a garbage can under it to scoop the dust into. To do this, I made a simple stand with spruce legs and plywood stretchers.
The corner gussets are cut from the circle left over from cutting out the ring for the centre section:

make a dust collector better

I can drive screws up through these into the bottom of the collector to attach the stand.

Here I’ve got it put where it will be in the shop, right next to the chop saw station:

make a dust collector better
make a dust collector better garbage container

The perfect height for the garbage bucket I have. This will really be a time saver over the original setup, and hopefully a lot less messy.

I removed the power switch that was on the blower unit, since I could no longer reach it. In its place, I ran a wire down the side of the cabinet to a switch mounted at a convenient height:

how to improve a dust collector
how to improve a dust collector

Easy to quickly switch it on before a cutting operation. I just used an ordinary light switch to do this.

Next up, the ducting, and I’m using 4″ PVC. To join the tee to the inlet, I cut a short length of pipe as a coupling:

how to improve a dust collector

The pipe is a tight fit over the inlet and I just screwed that in place using sheet metal screws.

I then extended the pipe over to the chop saw station. The pipe meets the side at an angle and I also want a blast gate here, so I need to make an angled box to fit:

how to improve a dust collector
how to improve a dust collector

The blast gate is just a piece of 1/4″ plywood with a stop on the inside, to keep it from sliding all the way out.

how to improve a dust collector

I cut the right size hole through the side of the chop saw station and screwed the box on from inside.
This is a little higher than the middle of the hooded area and works well to draw out the airborne dust from using the miter saw.
When I want to increase suction at the table saw or to use the hose, I can close the blast gate.

For the table saw, I needed to figure out the best place to put the inlet. Looking inside, I saw that most of the dust is thrown downward off the front of the blade into the bin at the bottom. I figured that the best place to capture the fine dust, is right there, at the front of the saw:

how to improve a dust collector
how to improve a dust collector

I marked and cut out an opening in the front panel of the saw. Easy enough to do with a zipcut blade in the grinder.

I then cut out a piece of 3/4″ plywood to fit:

how to improve a dust collector
how to improve a dust collector

Then made a scoop with more plywood and cut a 4″ hole in the bottom for the pipe.

Completed and screwed on:

how to improve a dust collector
how to improve a dust collector

The pipe then goes across the floor beside the saw.
There will be lots of people suggesting that this is a dangerous trip hazard, but for those of us that have some real world experience, and actually pay attention to what we are doing, this won’t be a problem.

Another blast gate stops flow from the table saw, and that is just below the inlet for the hose to vacuum the floor:

how to improve a dust collector
how to improve a dust collector

The completed project.

I have to say that at first, I thought I would not use this for some cuts, but find that every time I get ready to make a cut, I immediately turn the collector on. It is extremely effective at keeping the air free of dust while I’m making cuts, and has proven itself in the short time since I finished it. A project well worth the time and effort, transforming the nearly useless dust collector that I had into a valuable shop tool.

I made a short video going through the build, plus a brief demonstration at the beginning:

December 2014 Update

Well, it’s exactly one year later and I have decided that this type of dust collection is not what I need in my shop. Over the last year I’ve used the dust collector less and less, and eventually not at all. The fact is, the two tools it is connected to have very effective passive dust collection and really don’t need this large unit. The only time I would switch it on was for an extended cutting session on the table saw, and those events are fairly rare.
I came to this conclusion after a reassessment of the layout and tool placement in my workshop. There are a few things that I will be changing over the next month or two, and the dust collector is the first to go.
I made a video showing the work and in it I talk a bit about what I have in mind:

All of the parts will be saved and reused, including the plywood it was made from and the blower unit. I may experiment with a smaller, more portable design, something that is small enough to wheel around the shop for cleaning.

With the dust collector out of the way, I was able to move the miter saw station a bit further down the wall, and raise it up about 4″ higher. I’ve always found the working height to be a bit too low, so this will make it more comfortable to use. It also works with the new belt grinder stand that I will be building very soon, in that it increases the amount of space beneath the top of the stand. This will allow me to use that space to put another tool on a pull out shelf. My thinking is that it would be the perfect place to put my surface planer, since the stand for that is another project that has not worked well in my shop. But that’s at topic for another day.

Going forward, I will work to improve the passive dust collection on the table saw and may use another smaller shop vac for fine dust control. It would be wired so that it will turn on when the table saw is started. The vac would only work to capture the fine dust inside the saw housing, creating negative pressure to pull air into the saw whenever the saw is used.
The miter saw is very good as it is, but can be improved by closing in the hood as much as possible. I may look at making something that will capture the fine dust inside the hood, but right now that’s not a priority.

I should say that the collector did work well, but was not well suited to the situation. My shop is not used constantly, very little in fact, and dust control is not a big issue. The few times when I would create a lot of dust can be handled with the trusty broom and dustpan.
I’ve come to the conclusion that to have any kind of large scale dust collection in a small hobby-type shop occupies too much space and may be overkill. Much better to do what you can to capture the dust at the machine and have a small air cleaner running constantly to filter the airborne dust. Having the air cleaner turn on with the lights would mean it’s working while you are in the shop, and this is something I will be doing in the near future.