Big/Tiny Variable Dust Separator

by Superbender

44K59221

Intro: Big/Tiny Variable Dust Separator

With my increasing interest in woodworking and the amount of dust created in the process I needed to find a solution for collecting the dust created in my garage without clogging up the filter of my shop vac. There are plenty of solutions posted in the web which vary from buying and assembling commercially available dust separator systems to making your own. Here I am presenting the solution I came up with, that is as usual based on all the good stuff I could find on the web and then some of my own ideas. I went for the simplest possible design which turned out to be able to handle a wide range of machines and dust/shaving volumes with 'Version2'.

In a nutshell, I: (i) Avoided the cone shapes design most separators use and used a simpler design. (ii) Used for the first version a small collection container, i.e. a standard bucket, which worked well for small dust volumes created by a table saw or a miter saw. This version wasn't that great for large volumes though as the bucket filled up way to quickly. (iii) Switched for the second version to a large collection container, i.e. a 55 gallon drum, which worked well for larger shaving volumes created by a router or a planer as well as for small dust volumes.

Credits: The main inspiration, design ideas and grasp of concept came from many weblocations such as this, this, this, this, or this one.

Specifically this instructable by Steliart - Stelios LA Stavrinides sparked my interest in building a low cost separator by using buckets. Once I dug a little deeper, I found this instructable by TabLeft which opened my eyes to the fact that I might be able to build a much simpler vortex type dust separator without actually using a cone. I even found a video, that proved the concept of the design I was going after.

And here you can see what I did.

STEP 1: Materials & Tools

Materials:

List of materials and tools used for this build. I am giving home depot links as an example source of materials, but other hardware stores such as ACE or Lowes carry the items as well.

Tools:

  • Sharpie or other marker
  • Carpet Knife
  • jig saw
  • reciprocating saw
  • hole saw
  • cordless drill & drill bits
  • screwdriver
  • caulk gun

STEP 2: Interface Dust Collection/Dust Separator Bucket

We start with the interface between dust collection and dust separator buckets. The pictures of the building process are pretty much talking for themselves. I'll try to keep my explanations fairly brief:

  1. With the carpet knife cut out the bottom of bucket #1.
  2. Center the bottom of the bucket on a bucket lid and mark its circumference.
  3. Just inside the markings, cut a hole into the lid with the carpet knife. The ideal hole size allows the bottom part of a bucket to sink ~1/2" into the hole.
  4. Place the bucket lid with the hole on the bucket #2.
  5. Stick bucket #1 into the hole.
  6. Find a piece of wood that fits between bucket and the lip of the lid.
  7. Cut the piece into eight 1.5" x 2.5" pieces.
  8. Select a screw of the same length than the wood thickness.
  9. Determine the core diameter of the screw.
  10. Select a drill with slightly lower diameter.
  11. Drill 2 holes into each wood piece.
  12. Stand the bucket on a table, place one spare wood piece flat on the ground, stand another on top of it, and slide it against the bucket.
  13. Drill through one of the holes and fasten a screw from the inside.
  14. Repeat with the second hole.
  15. Evenly space out the remaining wood pieces around the bucket and repeat the fastening process.
  16. Turn the bucket upside down and place the lid with the hole onto it. If necessary, cut away plastic that prevents a good fit.
  17. Fasten the lid with screws on the 8 wood sections, by drilling pilot holes again before fastening the screws.
  18. Seal the crack between bucket and lid with HVAC tape.

STEP 3: Reinforcing & Preparing the Top of the Dust Separation Bucket

In this step we are completing the top of the dust separation bucket, i.e. the top bucket. The idea is to reinforce the top to give it enough stability to hold up the weight of the PVC tubes and the vacuum hoses. The thickness of the wood I had around was about 3 mm (1/8"), so I build my top out of 2 pieces of wood. One that fit inside the rim of the top and one that sat on top of it.

  1. Place the top of the bucket on a piece of wood.
  2. Mark around it with a pen.
  3. Cut it out with a jig saw or other saw.
  4. Mark another piece of wood from the inside of the bucket.
  5. Cut it out with a jig saw or other saw.
  6. Select screws that fit to the thickness of both wood pieces combined.
  7. Select drill according to screws.
  8. Place smaller wood disk in top of bucket top.
  9. Place and align larger wood disk on top.
  10. Turn everything around.
  11. Drill a few pilot holes into top & wood and fasten them to each other.
  12. Determine center of assembly.
  13. Drill hole with 2 1/2" hole saw through wood. Stop when you reach bucket top.
  14. At the same location, cut a hole of the same size into bucket top using the carpet knife.
  15. Measure distance from outside of lid/bucket to inside of lid/bucket. This was 1 cm in my case.
  16. Add 5 mm and mark the distance from the outside of the wood disk.
  17. Drill a second hole with the 2 1/2" hole saw so that that outside of the hole is on the mark.
  18. At the same location, cut a hole of same size into bucket top using the carpet knife.

STEP 4: Complete the Dust Separator Top With PVC Tubing

In this step we are mounting the PVC pipes onto the top of the dust separator bucket. Note this 2" piping has an inner diameter of 2".

  1. Measure the depth of the protruding part of the 90 degree bend, for example d = 2 cm.
  2. Measure the thickness of your wood/lid top assembly, for example t = 1 cm.
  3. Cut a piece of 2" PVC pipe with the length l = (2 x d) + (1 x t) - 0.5 cm = 4.5 cm using the reciprocating saw.
  4. Use a knife to deburr the edges of the pipe inside and outside.
  5. Put PVC cement on the inside of the 90 degree bend and the outside end of the pipe.
  6. Quickly press the pipe into the bend.
  7. Let it dry according to the instructions for the glue.
  8. Stick the short tubing piece through the hole at the outside of the top.
  9. Glue the tube to a second bend, arranging the bends as shown in the pictures so that:
    1. the bend that will end up inside the bucket would blow air in a circle around the bucket.
    2. the bend that will end up on top of the bucket will point away from the center of the bucket.
  10. Cut another 4.5 cm, two 6 cm, and one 25cm piece of 2" pipe and deburr them.
  11. Glue the 25 cm piece to the coupling and let it dry.
  12. Glue the 4.5 cm piece to the other side of the coupling and let it dry.
  13. Stick the short pipe end through the center hole from the inside of the top/bucket to the outside.
  14. Glue the third bend onto the pipe and let it dry. Note that I used an extra coupling and pipe length in my pictures. These are not necessary. You can go straight to the bend. Also make sure you are pointing the bend in a direction that is convenient for placing your shop vac. I used a 90 degree angle between bends.
  15. Glue a 6 cm piece of 2" pipe to each of the bends. These are for the hose attachments.
  16. Last not least, put some beads of silicone around the pipes at both the outside and the inside of the bucket. Let them dry overnight.

STEP 5: Hose Assembly

In this step we finalize the small version of the dust collector.

  1. I bought a new/second vacuum hose for this separator. It came with three hose termination options. Attach the smooth termination option to the hose.
  2. Attach one flexible 2" coupling to the hose and the PVC pipe that comes out of the center pipe / outlet of the dust separator. This hose attaches to the shop vac inlet.
  3. Attach the second flexible 2" coupling to the hose and the PVC pipe that comes out of the other pipe / inlet of the dust separator. This hose attaches to your saw, router, planer, whatever. In the picture this hose is the new shiny black one.

STEP 6: Test of "tiny" Version

It works.

  1. For once, clean up your workshop and sweep up a pile.
  2. Turn on the vacuum and suck the dirt through your assembled dust separator to the vacuum.
  3. Once the pile is gone. Check where it went.
  4. In my case it ended up in the lower "dust collection" bucket and nothing in the shop vacuum. Yeah.

However, I realized quickly that the "tiny" Version is great for the table saw and the miter saw. But for the router and the planer the volume in the bucket was too small. So I moved on to the "BIG" version.

STEP 7: Upgrading to the "BIG" Version

To upgrade you need (i) another bucket (or use the dust collection bucket of the "tiny" version), (ii) a 55 gallon drum that has plastic top (craigslist), (iii) silicone glue.

  1. Mark the bucket 1 -2 " below the widest rim.
  2. Cut the bucket along the marking.
  3. Take the cut off top part and center it on the drum's top.
  4. Mark the circumference.
  5. Cut a hole at the inside of the marking.
  6. Fit the bucket into the hole. Carefully shave more material off until the bucket top fits tightly.
  7. Put silicone beads on the inside and the outside of the bucket/drum top connection and let dry overnight.
  8. Done. Woodwork away.

Note that since I finished this separator I have routed, planed, cut, ripped, cleaned and sanded for hours. The drum still isn't full, but the shop vac is still empty. The "BIG" device is maybe a little spacious but otherwise an awesome addition to my shop. Pick your own size and let me know when you build one.

STEP 8: Update Step: Adding Wheels

After some time of successfully using the drum as a dust separator I followed some friendly advice and added wheels to the setup. Though the drum never really got as heavy as I thought it would, the wheels sure make it much easier to move the setup around.

Materials & Tools:

4 casters: $3.49 (on sale), Harbor Freight. Note that the brakes of these casters have a poor design. From 12 casters, a total of 4 had dysfunctional brakes. Otherwise the casters were fine.

Screws: #12 x 3/4, Home Depot or Lowes

Washers for #12 screws, Home Depot or Lowes

Wood screws: 2" long, Home Depot or Lowes

Plywood: 600 mm x 600 mm, 3/4" thickness, Home Depot or Lowes

Leftover wood pieces, e.g. 2x4 pieces

Saw

Drill

Drill bits

Step-by-Step:

  1. Measure the diameter of your drum. Mine was just smaller than 600 mm.
  2. Cut plywood to size using any available saw appropriate for the job.
  3. Sand the edges.
  4. Place casters on corners and mark hole locations for screws.
  5. Determine core diameter of screw and select drill bit of slightly smaller size.
  6. Drill 16x pilot holes.
  7. Fasten casters with 4x screws and washers.
  8. Turn setup around and place drum on it. Note: You could stop here. The drum was stable and not slipping, but I did a few more steps to prevent the drum from sliding.
  9. Cut four pieces of wood to a length of about 6".
  10. Sand the edges.
  11. Lay one piece next to the foot of the drum and mark the size of the lip on the board. Width and height of the lip of my drum were 7 mm and 10 mm respectively.
  12. Set your table saw (or router) to the same height, i.e. 10 mm.
  13. Remove the measured amount of material from the edge of your wood pieces, i.e. 7 mm x 10 mm.
  14. Place the wood pieces (i) with the groove down, and (ii) the groove toward the drum on the four corners of the plywood.
  15. Slide the wood over the groove and fasten it with the wood screws. Drill pilot holes as needed.
  16. Ensure that the drum is safely secured to the plywood.
  17. Done.

Now if you feel brave, put on a helmet, hold on to your drum, jump on the plywood and roll down a hill... all on your own volition and responsibility of course. If you don't feel brave, you may now go crazy with your vacuum in your shop and clean up for once. In any case, enjoy the setup.

21 Comments

dgood3 7 years ago

this looks great, very informative, organized, and easy to follow, just alot to digest. i will be making this in the near furture have some projects to finish for a craft show but this is my next build i hope i can ask ?'s if i get confused as i build thanks and awesome build

Superbender 7 years ago

Hi dgood3,

Sure. Ask away. I'll do my best to help. Just as a motivation, I absolutely love that separator. Works great and I use it all the time. Much more than I thought I would. Well worth the time spent on it.

schroeder1235 9 years ago

Looks great and I am going to be making one in the next week but I am stumped trying to figure out what is the advantage to keeping the 5 gallon bucket in the large version? Couldn't you just put the two pvc hookups directly in the lid for the 55 gallon drum?

Superbender 9 years ago

Hi schroeder1235,

I am pretty sure that the build would work as well without the separation between 'dust separator bucket' and 'dust collection drum'. I have listed one link in my write-up that uses a system with the same diameter for collection and dust separation, which is essentially a one drum system. However without having tried this and just thinking about the involved physics I think that you'd loose some of the effectiveness of the device when going to the large diameter drum only.

1) These type of vortex systems are based on a centrifugal effect that keeps the heavier dust particles at the outside of the rotating air stream. In the eye of the vortex the 'clean' air is sucked back out to the shop vac. The higher the velocity of the vortex the stronger the centrifugal effect. Smaller bucket = higher velocity. This is to my understanding the reason why many builds include a cone. Reducing the diameter keeps the velocity high even though less gas is actually rotating in the lower section because gas is entering the exit.

2) A strong shop vac will help for the same reasons as under 1).

3) The further the distance between the dust at the bottom of the drum/bucket and the end of the straight tube piece the better. For my setup the dust is rotating even inside the drum. That's due to the shop vac I am using. However, the more you stir up the dust, the more might end up in your shop vac. So it's good to have some spacial separation between the outlet and the dust.

In the end you'd need to try if such a setup does what you'd like. If if doesn't work you could always add the top bucket afterwards. In my case, I am very happy with the performance of the drum/bucket combination.

Good luck with your build and please let me know what you decided and how it went.

the_tool_man 9 years ago

I just finished a dust separator, built with just a 55-gallon drum. As you say, without the 5-gallon bucket on top, it is still just as effective...when empty. But as the drum fills with dust and chips, they eventually start getting sucked into the vacuum (or fan in my case). It happens surprisingly soon; with the drum only 1/3 full. I plan to use a "Thein Separator" to allow complete filling of the drum. But I see no reason why your bucket design wouldn't work nearly as well. Just thought you'd want the extra info.

schroeder1235 9 years ago

I made one now. I used the baffle and love it. I rigged it up with blast gates and have 3 inlets. Works great. Only thing I would have done differently is not used glue. The pipes for together plenty tight on their own and now I am S.O.L. if I get a clog.

Superbender 9 years ago

Great. I still love mine. Post a picture of yours if you find the time. I'd love to see one.

And so far, no clogs for me. I honestly wouldn't know what I'd have to do to create one, given my hose diameter and powerful shop vac.

Superbender 9 years ago

Awesome. I'd love to see a picture of it. I think a "Thein Separator" would help, although I seem to have good luck due to the sheer height of my separator.

the_tool_man 9 years ago

Great write-up. I would suggest that if you plan to fill up a 55-gallon drum with dust, that you put wheels on the bottom of it, or place it on a dolly. At some point you have to move it to dump it! Thanks for posting.

Superbender 9 years ago

Hi again,

Please see the added Step 8 to see how I added some wheels to the setup. It is a good improvement to the setup. Thanks again for the suggestion.

the_tool_man 9 years ago

You're welcome. I noticed your comment about how some of them didn't work well. For future reference, I've found the Chinese casters at the big box stores are better than the Chinese ones HF sells. They cost a dollar more. But it's worth it. With either one, it helps if you lubricate the swivel with a little grease, too.

Superbender 9 years ago

That is a great suggestion. It's half full right now and getting heavier by the day. I actually have some wheels around that I could use. Watch for an update in the the next month or two :)

OutlawKtulu 9 years ago

Excellent Instructable! I have a two bucket design using 5 gallon buckets, but my lathe likes to fill those up fast. I am going to have to upgrade to the 55 gallon design! Thanks for posting this!

Superbender 9 years ago

That's a quick switch when you have the plumbing done already. The hardest part is to find an affordable drum on craigslist or so. Good luck.

OutlawKtulu 9 years ago

I've seen the ones like you used at a local farm supply store for rather cheap.

agulesin 9 years ago

Nice 'ible, thanks!

just one question/point: Couldn't you continue with the hole saw? it would cut plastic as easily as wood and give a better finish than a knife. Better idea: Start from the plastic side so that the wood below will support the hole saw's center drill.

13. Drill hole with 2 1/2" hole saw through wood. Stop when you reach bucket top.
14. At the same location, cut a hole of the same size into bucket top using the carpet knife.

Superbender 9 years ago

Hi agulesin,
yes in theory that should be possible, however, I was afraid the plastic could rip since it was only fastened with a few screws. So I did choose what I thought was the safest path.

jayawilliams 9 years ago

I need one of these, but I'm confused by how it works. The confusing part for me that it seems the shop vac is pulling air from the center pvc in the bucket that reaches to the bottom... I would think that it would pull the dirt/dust into the vac after a short period of time. Is that the reason for the 55 gallon drum? Would the design work as well with a shorter piece of pvc in the center and then swap the connections on the top to pull air through the bucket from the s shaped pvc?

jayawilliams 9 years ago

I have now read more about the 'how' it works. Oops. Sorry.

tomatoskins 9 years ago

I've seen a few of these over the last few months. I think that I need to build one at some point in time. Great 'ible! Very detailed.

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