J. Phil Thien's Projects

Okay guys and gals, I have seen folks asking about this over, and over again, and I have seen Phil's answer that includes router table, or band saw and special jigs. I wanted to share with you my approach to the construction of a Thien Cyclone Separator lid. I have learned a LOT in the process of building my first one, and now the second is well under way. I hope this write up helps. I should note that this write up is done with the idea that it will be used for a 4" ducted system. If you are not using 4" adjust your sizes accordingly. Like Phil mentioned, there are no "plans" per se, and my solution may not work for your situation, but this is what I am doing to build my separator / baffles.

First things first, you need to obtain the materials to make your separator. I am using 3/4" MDF for mine since, honestly, it's what I have on hand. If had nothing on hand, I would have gone and grabbed some 3/4" sanded baltic birch, or Poplar plywood. For most builds a quarter sheet is really all you need, some need more than that... So here goes the shopping list.

        - 3/4" BB ply, or whatever material you chose. Pine is cheaper, MDF is even cheaper. Take your pick. If you go ply, get sanded, unless you want to sand your arms off.
      - 1/4" - 20 threaded rod. This is best purchased in 6' lengths. You will need to CAREFULLY cut this to shorter lengths making certain the threads are undamaged. Be comfortable with a file and possibly a thread chasing die.
      - 1/4" - 20 stop nuts A.K.A. Nylon insert nuts, nylock nuts, lock nuts etc... You will need 6 of these.
      - 1/4" fender washers. 12 of these
      - 1/4" - 20 standard nuts. 12 of these.
      - 4" S&D pipe nipple, OR 4" Dust Collection Hose Splice.
      - 4" S&D street elbow OR 4" Dust Collection 90 degree elbow.
      - Container. Your dust bin as it were. I am getting good results from galvanized steel trash cans.
      - Hot melt glue for a glue gun (and the glue gun) or clear silicone adhesive sealant.
      - sacrificial strip of lumber, or foam insulation or something to allow bit to cut through and not damage bit or floor. (or benchtop, or sawhorses, or... you get the idea I hope.)
      - 4" Dust collection hose, and clamps.

Next, you will need to assemble the tools needed for the project.

        - Router. Plunge or fixed base doesn't matter. Plunge is easier to start the cut with, a fixed base is a bit more dangerous to start the circle cut with.
      - Straight cutting plunge router bit. I used MLCS item #7751 3/8" dia, 1" cutting length, 1/2" shank plunge cutting straight router bit.
      - Rabbeting Router bit. I use MLCS #8366 9 piece rabbeting router bit, 1/2" shank. Set for a 3/8" deep rabbet cut.
      - Circle Cutting jig. I use the Craftsman branded version of the Milescraft 1203. If you don't have a circle cutting jig / edge guide for your router and want to buy this one, I STRONGLY advise you to immediately upon opening the box throw out the all plastic threaded knobs and replace them with 1/4" - 20 star knobs. I got mine from Rockler no problem...
      - Jig Saw with GOOD wood cutting blades. I have both a junk old Skil jig saw, and junk Black and Decker blades. They work, but are not ideal.
      - A means to sand the INSIDE of a circle. I am using an oscillating spindle sander, you can also use a sanding drum on a drill press to do the same job...
      - Work surface and clamps. I use junk sawhorses for mine and don't care if I cut into them.
      - Clamps to keep the work piece from moving on the work surface. 2 6 inch bar clamps work fine.
      - Hot glue gun if using hot glue.
      - Drill and drill bits.
      - Measuring and marking tools, specifically.
         - Sewing measuring tape. The flexible fabric kind to measure and mark the outside radius.
         - Straight edge with measuring scale. A carpenter's square SHOULD be enough, but might not be long enough.
         - Pencil.
         - LARGE drawing compass, or at the very least, a string.
         
Now that you have the stuff, we move on by measuring the top of the container, outside lip to outside lip. I am again assuming a trash can here.... An example.

   -Measure the outside lip to outside lip of the container in at least 3 different spots. Add those numbers up, and then divide by the total number of measurements to get your average. So for example your measurements are 19.5", 20", and 20.5" for a total count of 60 divide that by 3 for an average of 20. Now divide that number in half to get your radius (the space between the center point and the outside edge. That equals 10. Now that we have a radius, we know we want to overhang the edge just a hair to keep things from slipping in one way or another. Add 1/4" to that number. Now we have a radius of 10.25" right?
   - Measure and mark your sheet material. Say you are using a quarter sheet of MDF. Measure 21" up the long side, and using your square draw a line across, insuring it is square, measure the distances in a couple of locations to insure you have it right. You should have a sort of square, 24" wide x 21" high. Using your square line up the opposing corners of the square and draw a line corner to corner. This gives you the center of the square.
   - Drive the center point nail for the circle jig, and using your square, measure 10.25" from the nail, and draw a line.
   - Set the router up with the straight bit, and circle jig, Connect the jig to the center point, and adjust so that the INSIDE edge of the cutting carbide is touching the outside edge of the line you just drew. Lock the jig down.
   - With the work piece on a sacrificial piece, clamp it down so it won't move. Be careful to keep the clamps out of the path of the router.
   - If using a plunge router, set the plunge depth to 1/4", if using a fixed base, set the bit depth to 1/4".
   - Make your circle cut plunging or lowering the spinning bit / fixed base as neccesary.
   - Repeat the two steps above but adjusting depth for 9/16" depth, and finally 7/8", the final cut WILL protrude through the bottom. This is why we put it on a surface we can cut. This last cut you MAY need to move clamps around to keep the circle piece captive while you complete the cut.
   - Remove circle cutting jig, straight bit, and center point pivot hardware.
   - Repeat the above process but setting the radius of the circle jig to 9 - 7/8" for the baffle piece.
Now to cut the rabbet.
   - Set router up with rabbeting bit, set to make 3/8" rabbet, set bit depth no deeper than 1/2". I personally like doing 3/8" so that the distances are the same.
   - Clamp the circle to your work support. You WILL have to stop, restart the cut to move the clamps.
   - Make your rabbeting cut. I cannot succesfully do this via plunging, I simply sneak up on the cut and go to full depth riding on the bearing.
   - Test fit the lid. It SHOULD be a snug fit, if not, figure out what measurements were off and start over again.

Make the cutout for the baffle.
       - Using the sewing measuring tape, measure the outside circumference of the circle, divide by 3, and mark the start and end points on the outside edge of the disk.
      - Using your square draw a straight line from the marks you just made to the center point of the disk.
      - Measure, and mark 1.25" from the outside edge up on each of the lines you just drew.
      - using a compass, or string, pencil, and nail, draw an arc from the center point, around the long way to each of the 1.125" in marks you just made.
      - Using your jig saw, and possibly the drill / bits for starter holes, cut out the large radius notch.
      - Clean up with a sander if neccesary.
      
Cutting holes in the lid for the plumbing.
        - Center the pipe nipple / hose coupler and use it to draw the outline of the center hole.
      - use elbow and line it up to be as close as is comfortable to the edge close to the rabbet.
      - Use drill bit and create starter holes.
      - Use jig saw and cut out your holes from the lines you just drew being careful to stay inside the lines.
      - Using a spindle sander, or similar arrangement, "sneak up" on the fit for the plumbing so that you can just slide the plumbing through.
      - Sand the right side of the outlet of the elbow so that you can turn it in as close as possible to the side of the can.
      - Line up the baffle with the lid, and insuring that the holes and supports will not interfere with the plumbing, drill the 3 1/4" holes through both pieces at the same time. (This insures alignment.)
      - Insert elbow, align to get as close to the side as possible without touching, and hot glue in place, filling any gap between elbow and its mount hole with hot glue for a complete seal. Insure at least 1-1/2" protrudes for the hose to clamp to.
      - Cut threaded rod to 3 7" segments, clean threads on the ends. Install 2 normal nuts on each end, and a washer, allowing enough space to pass through the work pieces. Pass through from the inside, from the outside install washer, and lock nut.
      - When all 3 spacer rods are installed, adjust the nutsso that the distance is equal, and the elbow barely touches the baffle.
      - On the inside, screw the 2 nuts per side together in a "jam nut" configuration. This keeps it from backing off.
      - Insert nipple / hose coupler adjust to where the end is 2" from the baffle.
      - Hot glue the nipple / hose coupler in place the same way you did the elbow.
      - Connect inlet hose to elbow, clamp in place. If you are using S&D fittings, the fit will be snug, slip the clamp on, then work the hose onto the fitting and clamp it down. You are good to go. Same applies below.
      - Connect outlet hose to outlet, clamp in place.
      - Test.

On the web page http://www.jpthien.com/cy.htm I have two questions aboyt the photos:
1. There appears to be a wing nut in the center of the baffle on the underside. What is that for?
2. The baffle appears to be offset from center on the lid. Is this correct, or is it just a funny camera angle when the photo was taken?

In regards to #1. The wing nut. While that is Phil's photo, that wing nut isn't really part of the design per se. I believe the reason he has it there is simply to plug a hole in the hardboard he used.

In regards to #2. YES the orientation of the baffle to the inlet bend is important, and that is NOT an optical illusion. You want the solid part just starting as the air comes out of the inlet so it can ride around a bit before stuff drops into the can. I have seen (read I messed up and oriented it wrong) this done backwards, and scrubbing becomes a very real problem very fast...

Quote from: dbhost on June 30, 2009, 01:18:12 PM
...
In regards to #2. YES the orientation of the baffle to the inlet bend is important, and that is NOT an optical illusion. You want the solid part just starting as the air comes out of the inlet so it can ride around a bit before stuff drops into the can. I have seen (read I messed up and oriented it wrong) this done backwards, and scrubbing becomes a very real problem very fast...

I am confused by some of the pictures as well.  However I think that rfcomm2k's comment is based on a picture where the camera is not lined up with the center of the baffle AND lid.  So, it appears that the center of the baffle is not at the center of the lid OR the trash can.  This would result in an aperture (hole where the dust falls to the bottom of the trash can) that would look like 2 half crescents and some sort of hard to describe arc.  Bizarre.  This is most likely incorrect.

I think the center of the lid AND the baffle AND the trash can are all the same.  I think the aperture looks like a ~1 inch 240 arc.  The arc appears to start about 200 degrees after the inlet pipe and ends about 40 degrees before the inlet pipe.

Do I have that right?

-thanks everyone for contributing!

You are close to right. Yes the center of the baffle is indeed the center of the lid, and yes it is over the center of the trash can, drum, or whatever your vessel is.

The elbow in question empties out at the start of the solid part, not the drop slot, or aperature as you called it, so that they loaded air is slightly deflected away from the shavings / dust below.

The slot / aperature is 1-1/8" wide. I do not know why Phil designed it this way, and if it needs to be adjusted for larger sizes. For my HF 2HP DC I made the drop slot 1-3/8" wide by sheer measurement mistake and it still worked fine. On the one I am building for the 55 gallon drum, 4" pre separator the drop slot will be 1.25" wide. Right or wrong that is how it will be made.

Hope this helps, and sorry about the slow reply. I didn't notice your post for the longest time...

Quote from: dbhost on September 11, 2009, 01:06:50 PM
You are close to right.
...
The elbow in question empties out at the start of the solid part, not the drop slot, or aperature as you called it, so that they loaded air is slightly deflected away from the shavings / dust below.
...

Good thing you took your time as it gave me a chance to finish up my dust collector.

My inlet elbow starts at the beginning of the solid part (where the bottom plate meats the side of the container) but the opening is actually about 1/3 the way past that.  It looks just like the picture except I am using 4 inch S&D pipe and a 20" (approx diameter at top)  recycling can.

I believe it is doing a fine job - but wished it was trapping more of the fine dust.

I would say my Thien separator is removing about 75% to 80% of the saw dust generated from my table saw. The reset, I think, is ending up either on the floor of the filter box (which is about 4 x 2 x 2 feet - a really massive space) or on the filters them selves.   But this fine dust is really hard to quantify let alone collect.  (The generous space in the filter box was for a set of mini cyclone filters that I never implemented - as that design got more and more complex.)

As for the fine dust collection problem - I have noticed patches of fine dust clinging on the top of the bottom Thien plate.  I think I have see the same on pictures here of other people's Thien separators.  There seams to be a space of low turbulence on the way to the exhaust or outlet connection.  Is there a way to exploit this and remove the fine dust?

I was thinking of cutting yet another circle about 6" wide (in my case) in the bottom Thien plate and raising it about an inch.  This might give the fine dust travelling to the exhaust an opportunity to drop into the collection bucket.  But I think all this will do is create turbulence in the lower part of the bucket doing more harm than good.  Perhaps if this second opening could be isolated (a bucket with in a bucket) there would be no chance of additional turbulence.  Of course, my Thien design just got all that much more complex.  If I have any success with this idea I'll try to post a follow up.

Sorry for my dribble...  Is there a better thread to talk about modifications?  Or are you all ok w/talking about it here?

-thanks everyone for working and putting thought into this project.

I would probably start a new thread, and perhaps ask Phil directly about that issue with the underside of the baffle. I noticed it on mine too.

Yeah, 1/3 is the solid part, 2/3 is the open part...

I am a bit concerned you are only removing 75% of the dust though.... Is it just not getting picked up and ending up on the floor / on your saw (that would be a dust hood problem, or insufficient CFM etc...) or is it ending up in the filter / filter bag? (or whatever you are using if not using an off the shelf single stage DC).

As far as I can tell, and I have never asked phil about his concept here, but it seems like the idea is to keep the air spinning long enough for debris, and dust to fall out of the air stream, air smashing against the sidewalls of the container should do that... In turn the solid center section keeps the stuff that has already gone into the dust bin from getting sucked right back up into the filter.

You will always get some ultra fine dust that goes through your separator, but it shouldn't be much...

Unless I overrun my dust bin, I generally get about 1/2 cup of fine dust up into the filter / vac on my shop vac based setup for every 10 gallons of fine dust and mixed material I pick up.

My shop vac filter is pretty well caked too.... I use it primarily for cleaning the shop floor, and for my palm and RO sanders, so LOTS of fines get sucked up. I'm thinking a smaller diameter separator could help.

Quote from: dbhost on September 11, 2009, 03:17:48 PM
...
I am a bit concerned you are only removing 75% of the dust though.... Is it just not getting picked up and ending up on the floor / on your saw (that would be a dust hood problem, or insufficient CFM etc...) or is it ending up in the filter / filter bag? (or whatever you are using if not using an off the shelf single stage DC).
...

My set up is custom all the way and is built around a old AC 110 volt powered GE furnace "squirrel cage" fan.  I wired it up for both cooling and heating speeds. So I think the fan's CFM is not an issue.  I am seeing dust on the 2 20x20 high efficiency filters and on the floor of the (way over sized) filter chamber (which is about 16 cubic feet).  What I should do is tune up my Thien separator.  I used the original can's latching lid which now has to sit proud of the can because of the added wood.  Some weather stripping run around the inside rim should fix that.  Also, the can has drain holes I only taped over.  I suspect they are leaking and should be silicon sealed.  Last, I have to find a better way to mount the 4 inch S&D pipes.  They are currently fiction fitted and are "kind-of" staying put. After the tune up, I'll do a thorough cleaning of the system (which is quite large - my bad) so as to easily identify any new dust collected past the Thien separator.  Maybe I'll get better results then.

Quote from: dbhost on September 11, 2009, 03:17:48 PM
...
Unless I overrun my dust bin, I generally get about 1/2 cup of fine dust up into the filter / vac on my shop vac based setup for every 10 gallons of fine dust and mixed material I pick up.

Wow - really?  I definitely need to tune my system up!

BTW - where is most if not all your dust from?  I have been cutting plywood which tends to make fine dust.  I was thinking once I get my router table running that would produce larger dust and chips which may be easier to separate (i.e. I am expecting the Thien separator to work really well with the router dust).

Quote from: CharlieL on October 03, 2009, 10:04:59 AM
While air leaks are obviously not good, even after you do fix those leaks don't expect the seperator to get 100 percent of the dust, especially the fine stuff. Even the cyclones that are built for the masses don't get all the dust, especially the fine stuff. In my opinion, a seperator, and or a cyclone is designed to get the big stuff so the blower doesn't have to deal with it, and it cuts down on bag changes due to being full.

Yes, I understand this.  And I really appreciate the elegance of the Thien's design as I've tried to make my own cone shaped separators. My dust set up is totally home grown and I am (subjectively) seeing (actually feeing at the exhaust) some issues in air flow reduction due to clogged filters (about 800 sq inches of higher end furnace filters - I don't remember the MERV (spelling?) of the filters).  I haven't settled on the overall design so I haven't had a chance to clean everything out and install new filters to see if "tuning" my Thien separator will make a significant difference.

Right now I have a huge cavity in front of 800 sq inches of flat filters.  I was going to put my separator in there, but the dimensions of the "let's quickly put a Thien garbage can separator together to see if it really works" exceeded that of the cavity.  The cavity is about 2x3x4 feet.  Any suggestions would be appreciated (i.e. put a second smaller Thien separator in there, two tandem Thien separators in the cavity and get rid of the big one, where to get a 2x2 foot garbage can, ect...)

-thanks

Question on the plans: Exhaust air ducting...

Ok, the exhaust air leaves in the center of the 'top' of the baffle, that is the center of the 'lid'. 

How far down does the exhaust air duct extend below the top of the baffle or how much room is required above the bottom of the baffle to the duct to make sure it all works well?

In the pictures it looks like it is not even with the 'top' baffle and sticks in about half way between the 'top' and 'bottom' part of the baffle/lid.

TIA... Jack

That's about right. On my shop vac sized unit, the tube extends 1.5" down from the top, on the 55 gallon DC model, the tube extends 2.5" down. I did not measure super careful or anything, Just kind of shoved the nipple in there until it looked right and applied silicone sealant...

Phil,
I saw your article 2 days ago on how to build a cyclone separator.
It was exactly what I wanted for my shed/garage arrangement.
I was so incensed that I have modified it and built it and it is FANTASTIC!
Thank you so much for making my life so much easier, love your work.
My modifications:
I used 50mm PVC fittings for the lid - none of them are glued as they are a tight fit (for the moment) and that allows for a great deal of versatility. I may have to glue some pieces as it ages, but we will see.
The distance from the top plate to the lid is 120mm, to suit the fittings.
I have used a couple of swimming pool pipe fittings (Australian type) to allow rubber fittings at the tools and the vacuum.
I have also used a 60 litre steel drum as the waste receptacle, these are easy to come by from old oil drums.
The rest is pretty much your design. A great idea.http://www.jpthien.com/smf/Smileys/default/smiley.gif
I have attached a few photos to show how it was done.
I look forward to any criticism or comments and other worthwhile projects.

Hi Guys again - this is a veritable Pandorra's box! Since making my 1st top entry Thien Separator and then read quite a bit of the other related threads, I want to put a question to the forum after a little bit of preamble.
The Thien Separator does a wonderful job and I see no dust or chips entering my wet/dry vac.
1.   Given the separator is so efficient why wouldn't a non-filtered tophat unit be fitted to a can and directly vented to the outside air?
Comments please?

Oz... 
Venting to the outside is certainly a viable option.   However there are a few things to consider. if none are applicable, then it is your best solution... 

1) Legal.  While a private homeowner can open his garage door and spread his dust and chips to the atmosphere, few municipalities allow a commercial business to do so.  The SCAQMD (Los Angeles), requires a permit for ANY duct that exits a building (even passive chimney hoods).  It MUST be filtered, and you must document any emissions or contaminants contained in the exhaust.  Since California has Prop 65 which requires disclosure of any materials which containing carcinogens and most hardwoods will give you cancer if you eat over 12 boardfeet a day, you are technically spewing cancer to the community.  Fortunately, there are only a few isolated cases of enforcing these laws, but it is coming... 

2) Good neighbors.  That exhaust duct will also emit sound as well as air.  How close is your neighbor's bedroom window?  Or, your sleeping infant? 

3) Winter's are cold (even in SoCal).  For every CFM you exhaust, another CFM has to enter your workspace.  If you are conscious of the cost of heating or cooling your workshop, your utility money is blowing out the duct.  With a 600cfm blower, a 20x20x10' workshop gets the air replaced every 6.5 minutes.   

4) Ooops!  The Thien Separator works so well, you tend to forget it.  I assume that most of us have let their separator overflow at some time or another.  When that happens, 100% of your debris goes out the exhaust.  Will that become mulch in your flowers?  Or, did you just spray your neighbor's driveway?  (with his new Harley parked downwind...) 

If none of these factors come into play, then count yourself as one of the fortunate few who have a system that is simpler and cheaper to run than most! 

Hope this helps!
Jim

Thanks so much for your reply Jim, some interesting points that I had not considered.
Although I do appreciate the issues you raised I have to add a little perspective however, I write this from the most isolated city in the world, Perth, Western Australia (WA). Some say that the time difference here is directly proportional to the years behind the rest of the civilised world (tongue-in-cheek) and that WA means "Wait Awhile"!
Fortunately we do not have these over-zealous bureaucrats and restrictive laws, yet, relating to venting and filtering externally.
My workshop is in one half of my garage in my residence so it is not a commercial concern and the winters here are not anything like you experience. Min temperatures here in Winter average 8 deg celcius (46 degrees F).
I have found that the separator just works magnificently, I'm very pleased to have come across the design and have been able to construct it so simply and cheaply.
More power to the forum - well worth the effort to join and contribute.
Warren

I don't see the measurement for the Thien slotted baffle is it the same diameter as the inside diameter of the trash can except for the slot and how much space between the slotted baffle and the bottom of the lid?  Thank you .

Hi tvman44, the diameter of the baffle is the same inside diameter as the can, and the baffle is placed approx 100mm below the lid. This arrangement is working very well although I do get some very fine dust through to the vacuum filter when I hook it up to a fine sander. Maybe a fine filter (stocking?) over the inlet to the vacuum may help?? Thanks for your feedback. Cheers

Has anyone tried paint scrapings and dust as a souce?  I am considering having this or something like it between t he HEPA filtered vacuum when using a paint shaver  (Paint SHaver Pro) and sander that have a vacuum hose attachment.  Dealing mainly with painted siding on a >100 year-old house but will also be using it indoors.  Thank you.

I used the Metabo version of the paint shaver.  The volume of paint isn't that great.  I'd suggest using a good quality bag (drywall bag), and HEPA filter.  I did my 2-1/2 car garage and filled one bag about 1/3 full.

A word of warning perhaps about the removal of paint from a 100 year old house.
There may be "lead based" paint underneath all those coats of paint.
Please use all necessary precautions when working around this paint.
Cheers

Quote from: ozwaz on January 04, 2012, 03:17:06 AM
A word of warning perhaps about the removal of paint from a 100 year old house.
There may be "lead based" paint underneath all those coats of paint.
Please use all necessary precautions when working around this paint.
Cheers

When I did this, I used the drywall bag and the HEPA filter, and I oriented the vac's blower port so it was blowing away from people.  I also wore a mask.

A couple of times after I started the process, I used some of those little lead detection sticks to see if I was getting lead on my mask, tool, hands, vac, etc., and could find none.  I know the paint contained lead, as I tested it before removal.

So I'd suggest being safe and test for lead before you start, and test a couple of times during the process to make sure you're containing the lead.  And don't let the kids play nearby while you're doing this.

Hi Folks,

I am very new to dust collection, and fairly new to woodworking (6 months). I needed to do something about the dust in my shop. I am spending 30% of my time cleaning up with the shop vac. One day when I finished, my nose and throat felt very sore.

So I finally purchased the Harbor Freight 2 HP dust collector.

I would really like to install dust collector with the Thien Cyclone separator. My problem is I don't have the skills or the tools to make the wooden baffle/separator. Is there a place where I can buy one ?

Also, the HF machine comes with 2  4"  intake connections, I would like to use 2 connections, Can the garbage pail have 2 connections? Or, canI put a 6" intake to the can, then split the6" to 2 Y's ?

For now I am going to install it as is, but with the Cartridge filter.

Thanks
-Fred

hi there fred
you wont be able to buy one of phils designs.
phil doesnt mind people building them for there own use but wouldnt like someone making money building them.
the beauty of a thien baffel is that it is easy to make with a few tools and can be made in many different ways.
i wouldnt be bothered building one with all the bells and whistles just yet. build a basic version that works. that way as your skills grow you can rebuild with all those extra bits.
a basic version should be a less stressfull build and easier to build with less 'skills'(dont underestamate yourself)


what tools have you got. im sure we can help you come up with a design that fits your needs.


i built my seperater using layers of mdf. i cut them 24"x 24"
i then jigsawed out a circle out of each layer. i cut a line at a tangent to the circle  and another the width of my transition
i sanded that layer to the corect shape and then screwed the next layer to the sanded one.
i then used a bearing guided flush cut router bit to make the layer the same as the one below it.
i glued and screwed al the layers on one at a time .
it worked great
i put a layer of plastic on the top of mine with a mdf layer with holes in it. you wouldnt need this. a solid mdf piece would work just a s well
the bottom and baffel are cut out of one piece. i glued and screwed it to the bottom of the built up  section.
i then drilled a hole and routed around with the bearing flush bit leaving the solid part of the baffel
i then measured out the 1.25" and jig sawed ou the rest of the slot
i put a slot to sit onto my barrel. im sure a few scrap pieces put around the top of the barrel would allign it well enough. some foam weather stippping seals everything


i fi was to rebuild it in the morning with the fewest tools posable i think i could get away with a jigsaw,router and flush bit, and cordless drill

I built my first Thien separator (a top hat) using a hand-held jig saw, a hand-held belt sander and a battery powered drill-driver. The beauty of the design is that it is so darned effective and yet so stupid simple to build.

The plans suggest 3/4 inch material, but I don't know if this was a selection made by convenience or if there is a structural thing I'm not recognizing.  I started out wondering if 1/2 inch Baltic birch wouldn't work as well and at 30% less weight.  Then I read about the desirability of the surface being slick.  Now I wonder if a melamine finish (or even high pressure laminate) yields benefits worth the extra effort. 

My question: Does a Formica clad half inch Baltic birch plywood baffle make sense or is it overkilled but out of spec?

Now  a weirder question.  Has anyone built, successfully, (or tried and scrapped the idea) of inlaying acrylic viewing windows into upper and lower baffle members, in-line, so you can look straight through into the can?  I say inlayed because if properly executed, there should be no turbulence resulting from a "really smooth inlay" (if such a thing is possible).  I briefly explored making the baffle members of acrylic until I learned the cost of acrylic.

the slicker the surface the less resitance there will be. formica or melamine will really help.

i inlayed in 3" windows into the top of the plates that seal up the rings on my dc blower. i put 3/4" mdf top and bottom. then a pipe to out side through one of them.
i holesawed a hole then rebated it . i siliconed in a plastic disk. on the dc blower they are flush to the inside so that the air is forcing them against the rebate. if you did this on the seperater the sucktion would pull them in.

the best option would be to go with a full layer of clear plastic . i did that on my 6" seperater , i put a 3/4" mdf ontop and cut holes in that

there is a build during the wek where it has a clear top and baffle plate

Thanks, Alan.  What do you think about the other part of the question, using 1/2 inch stock?

I don't understand your last sentence, "there is a build during the wek where it has a clear top and baffle plate."

some one during the past week posted a thread about a seperater that has a clear top and clear bafffle plate.


1/2" ply should be easily strong enough.

Thanks for your help.  I'll find the thread and see if I can learn where he got the polycarbonate or acrylic and whether or not I can afford it.

Is the width of the drop-slot related to the diameter of the lid/container? If I understand correctly, the plans refer to a container diameter of about 20.5" with a 1.25" wide drop-slot.  I am making a separator that will fit into a drum with a diameter of just under 16". Should I reduce the width of the drop-slot proportionally?
This is my first build. Browzing through the forum, I assume that it will not be my last, as I continue to learn, that is, make mistakes and try to figure out what went wrong. Thanks for your help.

the width of the drop slot should be constant.
althow it is a compromise between wide for the biggger material but less efficient and smaller but only allows down smaller chips.
if you wanted the seperater only for sanding or mdf ect you could reduce down the slot to 3/4" and try that.
its easier to widen later than to narrow

Just recently fired up my 30 gal trashcan I threw together over a year ago
I used  5/8 inch partical board - 2 layer for the top - used standard 4 inch stove pipe  elbo- and exit(straightened)
close fit and bonded with liquid nails , for the baffle I used 3/16 masonite and supported by small wires ,  hanging about 4-5 inch gap , I had to add a small 1-1/4 foam block at center of baffle to keep baffle from side of trashcan.. I never could decide on a blower, but  have now directly top mounted my old sears leaf blower on the center pipe and currently expel back into shop ( I do little sanding ) plan to filter later....
I'm amazed how well this is working ( a 32 gal shop vac ) I see nothing being expelled , but I'm sure fine dust is.
I'm running a window fan(sitting on floor) with a furnace filter attached on slow speed to   to catch some of the fine stuff.  The can in now 1/2 full of jointer and table saw  and floor shavings ....
Problem is now the bearings in my 40 year old leaf blower are going  bad ....
Again I must say my CLUDGE is working great,  then again maybe I just got lucky.......

Ok, I may be missing something, but are there COMPLETE plans for a separator using a 5 gallon bucket ?

Quote from: tommitytomtom on April 24, 2014, 09:26:13 PM
Ok, I may be missing something, but are there COMPLETE plans for a separator using a 5 gallon bucket ?

Nope, it has been done 100 different ways.

Ok, since it's been done a 100 different ways, has there been a study on how efficient certain designs are versus others ?

 This is a site that encourages independent though, experimentation and sharing results not just plans. There are a lot of builds here with ideas and results from various designs. I wonder if you have read enough of this fabulous web site? With respect that is the only way you are going to understand enough and get the full benefit. It is great fun.
Hope it goes well and please let us know about your build and how well it works.

I'm ok with the independant thought and experimentation. I can build it, and I have cruised around this site. I will gladly post my designs as soon as possible. My approach will be from a certain ".ca"'s perspective. Looks like I'll build the cyclone at some time too.

Great news. Go to it.

I would like to thank all the contributors of this topic.  I got a HF DC on sale total ~$160.  Turned it on it's side, used the Wynn filter, made the trash can baffle and now have a decent dust collector.  All of the construction ideas was from this site, except for a few minor tweeks. Works well and I am pleased.  Keep up the experimentation. 

New to this group, been away from woodworking for a while, but starting up again.  I have a Delta 50-760 DC with 5 micron bag.  Now that I'm starting up again, I'm upgrading my DC.  I had a 35 gallon fiber drum that I wanted to use as a separator for many years, but never set it up.  Then found the Thien baffle. I had a couple of 4" connectors from Rockler, but never used them.

After discovering the Thien, I bought a 30 gallon drum, installed a baffle and mounted the drum on the cart with the DC.  Will post some pictures.

Next upgrade is to add the Wynn 1 micron cart.  Hope to have it this week some time.

Hello all. Brand new here. Discovered Mr. Thien's baffle through of all places, YouTube! lol I've been an avid woodworker for 40 plus years, but had quite a spell where I just didn't have the time to do anything. I'm getting a shop back together now, upgrading/modifying some of my tools, building jigs, etc, etc. Just like so many others. I will post a help question in the next day or so, and hope you experienced folks can help me. Before I discovered the "Thien baffle" and all the separators built on it's design, I found a dust collector build on YouTube that looked appealing to me, and from the video I watched, it looked like it worked well also. So I ordered a fiber drum, and built it! Made a couple boo boos, corrected them, and finally thought I was done. Let me add also, that I don't own a DC, but rather use a 16 gal, 6.5 peak horsepower shop vac for my workshop cleanup tasks. I just didn't know any better! I can't really afford a DC right now anyway. OK, having said that, the vac works fairly well for what it is, and I get nice airflow through my new fiber drum collector/separator. But what I'm finding now, is the shop vac is "scavenging" some dust/planer shavings/debris, from the bottom of the drum, even when the hose is just laying on a clean floor, and not actually being used to suck up stuff. It's not extreme, by any means, but it's more than I think it should be. So I'll post some pics of my build, and ask for y'all to help me,and give me guidance/suggestions. Like any other subject with which we are unfamiliar, I'm learning so much, and have become fascinated by this whole "dust collection" subject. I appreciate all the hard work and experimentation you all have put into this, and hope to be able to contribute myself someday, to help others. Ok, enough introduction. Thanks for having this discussion group! 

I am sure a Thien baffle will sort out the scrubbing. Can you give us a link to to the "U" tube build?

Hi. Thanks for the reply! Yes, here's the YouTube link: https://www.youtube.com/watch?v=lNDc66V1_64
I also just realized I put my intro in the wrong place. Not totally sure how I screwed that up so bad! lol Anyway, I'll copy and paste it where it goes. I also have pictures ready to upload for a new thread I'll start for my help question.

I am truly impressed by Phil's efforts and the efforts of those that attempt to beat back the dust dragon.

Myself I think that the one thing some of us might have going for us is simplicity. In my case, much of my woodworking activity involves hand tools. I make chips more than I make dust and I make them in a way that allows me to clean then up without much trouble. My power activity is restricted to anything from dust to very fine dust and power tools that are not handheld are two only. I can feed dust from the handheld power tools into a simple dust collection system without much trouble fortunately and my actual tool drops are few and close by each other.

But this dust collection thing is such a complicated area of endeavor. Once you bring multiple drops over distance and different types of workshop materials for cleanup into the picture, the ability to suspend in air the really small dust particles long enough to get them into the spot where you want them collected, combined with things as large as wood chips is a tremendous challenge it would seem. In addition, it does not appear to me to be an environment where larger or more powerful in terms of blower is necessarily a big part of a solution. We would like to think we can always brute force our way through something. But it appears to me that particularly given the need to suspend really tiny dust particles, the right size blower for a particular system vs the largest is not just better but critical.

In my case, I have this Woodstock W1049 lid well sealed on a 30 gal. can for a separator and it works remarkably well. I fully expected that it would not work at all frankly. Yet at least to date, in a rather small sample size, everything that I am making with power appears to be finding its way to the bottom of the can under the lid. Now I have to believe that some very fine dust is up in my canister filter. But cranking the cleaning arm on the filter has yet to drive it down into the bag. My bag is still empty and everything appears to be in the garbage can.

So the things that have to be responsible for my good fortune to date are:
- proper sealing of fittings
- very limited number of drops (basically one 4" tool port and 1 drop to a hood which I also detach and midify for haldhelds)
- very short runs of hose (4" in and 6" out of the separator to the DC)

Honestly I just don't believe that my stretch of good luck will last much longer. So I am going to build a simple Thien in the sense of having it suspended inside the can as opposed to a top hat or I am going to build the simplest top hat version that has plans I can use. I am going to try to retain my 4" in 6" out approach to the hose. I suspect the difference between the two is helping to encourage the dust into the garbage can instead of heading for the impeller and filter of the DC. So I want to try to keep that I think.

I do have a question about the baffle. I saw one proponent of the Thien system who claimed that the baffle drop should be half the diameter of the inlet. So a 4" inlet would make a 2" drop. However in reading posts here, if you are producing mainly dust to fine dust there is the view that a smaller than standard drop is better. Is that anecdotal information or do you guys that really have a basis in information and experimentation agree with that view? If so, is there a size for the drop that makes the most sense? I have seen 0.75" forwarded as a possibility.

Again, I am never going to have a complicated system of multiple drops over distance. So the very reason this most simplistic solution that I have now works at all should also help me make a Thien work more reliably giving me more confidence that I will be surviving on more than blind luck......I hope.

I am going to modify my HF dust collector based on the Thein baffle. I plan to exhaust my >5 micron dust outside via a dryer vent set up rather than using a cartridge filter. Has anyone done this and is there a problem with this as long as I knock out the big stuff (saw dust, wood chips, wood slivers etc.)? I don't want anything but 5 micron or smaller dust going through my DC impeller anyway. I was working on ways to do this and researching when I found the world of info on the Thein baffle and HF DC modifications. Thanks Phil and all you other folks that have used Phil's baffle design and so graciously shared your experience, photos, plans, materials lists and so forth.

Quote from: dbhost on September 11, 2009, 01:06:50 PM
You are close to right. Yes the center of the baffle is indeed the center of the lid, and yes it is over the center of the trash can, drum, or whatever your vessel is.

The elbow in question empties out at the start of the solid part, not the drop slot, or aperature as you called it, so that they loaded air is slightly deflected away from the shavings / dust below.

The slot / aperature is 1-1/8" wide. I do not know why Phil designed it this way, and if it needs to be adjusted for larger sizes. For my HF 2HP DC I made the drop slot 1-3/8" wide by sheer measurement mistake and it still worked fine. On the one I am building for the 55 gallon drum, 4" pre separator the drop slot will be 1.25" wide. Right or wrong that is how it will be made.

Hope this helps, and sorry about the slow reply. I didn't notice your post for the longest time...

Is there a "rule of thumb" for the size of the slot in the baffle?  I'm thinking that the area of the slot should be similar (larger?  smaller?) to the inlet or outlet area.  This information would help in scaling the design to other duct and drum sizes.  I expect that the angular dimension of the slot at 240 degrees is fixed so the only available variables are the slot width and the diameter of the drum.  Any comments and suggestions welcomed.

The width of the slot is set to suit the material being handled. The narrower the slot the finer the material separated and the wider the slot the coarser it may be.

Clearly if you are separating wide long strips from a thicknesses then the gap needs to be wider - on the other hand if you are separating dust from a sander only then it needs to be narrower.

Note the start and end of the slot is critical straddling the inlet rectangle (pipe). So it ends just before the inlet and starts again on the other side so leaving a "platform" spanning the space under the rectangle. The leading edge of the slot needs to be tapered down so that big shavings don't catch on it.

I hope this helps and it would be good to hear how you get on.

Quote from: jgarner101351 on March 08, 2016, 01:33:11 PM
I am going to modify my HF dust collector based on the Thein baffle. I plan to exhaust my >5 micron dust outside via a dryer vent set up rather than using a cartridge filter. Has anyone done this and is there a problem with this as long as I knock out the big stuff (saw dust, wood chips, wood slivers etc.)? I don't want anything but 5 micron or smaller dust going through my DC impeller anyway. I was working on ways to do this and researching when I found the world of info on the Thein baffle and HF DC modifications. Thanks Phil and all you other folks that have used Phil's baffle design and so graciously shared your experience, photos, plans, materials lists and so forth.

The biggest problem aside from adding dangerous sized particles to the outside air and contaminating it (we are trying to clear the air right?) that I can see behind unfiltered outside venting is you will be moving heated or cooled air away from your workspace at 1K + CFM. You'll never be able to effectively heat or cool your shop making it, depending on your climate of course, a nasty, miserable place to work. I wouldn't (and didn't) go that route for just that reason.

DB & JGarner -
If you are fortunate to live in a climate where you can work in your shop most of the year without heating or cooling, you are tempted to discharge outdoors.  Our primary task in dust collection/filtration is to keep the particles out of our lungs.  Overall environmental cleaning is a noble idea, but idealistic if not unreasonable.  Releasing 1 micron particles into the atmosphere is not considered by regulating agencies because its dispersal is so great that it becomes irrelevant.   We would be better off trying to regulate pollen and hay-fever sources because they are much more harmful to human lungs. 

However, dust concentrated within an indoor space, is extremely important - which is why our dialogue on this website continues. 

Since my primary concern is to keep those dust particles out of my (and my co-oworkers) lungs.  I am sometimes in situations where I cannot collect the dust and chips and fumes into my DC.  At those few times, I simply place a HEPA filter over a box fan and blow it from behind us across the dust source(s).  This keeps a supply of clean air for us to breather while the particultes are blown away.  Once the dust settles, we can remove our filter masks.  Later, we suck it up into a shop vac with a Thien separator installed.  All clean!

Many Thien baffle enthusiasts have been searching for methods & modifications that might improve in the separation of fines/"wood flour".  In researching my own build, a possible solution has occurred to me:

In many pictures and videos of Thien separators—especially those that make use of transparent acrylic &/or polycarbonate—very fine sanding flour can be seen 'sticking' to the separator as a result of electrostatic forces.  This is hardly surprising, since high velocity particles rubbing against either of these materials is reminiscent of the static experiments many of us did in school, rubbing an acrylic rod with wool in order to demonstrate a negative static charge.

My idea is to exploit the electrostatic properties of these plastics in order to exaggerate this effect and remove a higher percentage of sanding fines during dust extraction.

This could be trialed very easily by temporarily fixing something like a wool buffing wheel to the EXTERIOR of the separator assembly, where it would create an initial negative static charge on the plastic surface.

Theoretically, this would result in MORE of the fines adhering to the inside of the plastic—in turn, creating a small amount of additional turbulence—which might further exaggerate the effect by slowing the cyclonic air path.

Of course, the fines wouldn't be expected to drop through the Thien baffle until the collector and 'static generator' is turned off, at which point the mass would drop under its own weight, or with a gentle tap.

If this worked, it might permit a more versatile dust collection solution, where a conventional Thien baffle is used for coarse material, and where the 'static generator' is employed on the exterior of the otherwise UNMODIFIED Thien separator during tasks like sanding, where a higher quantity of fines is expected. 

...Wondering if anyone might be in a position to test this concept properly?

Just a thought.  I am most grateful Phil's generous design offering and everyone else's contributions.

Has anyone tried to use the separator design to modify their shop vac directly? Seems like one could save a lot on filters if it was useful.

Yes, I realize that this is not the way a dust collector works usually.

But, I use my vac mostly as a vac. My shop area is small and I don't use it enough to rig up an actual dust collection system. Or, if I did, I'd just hook up the vac directly.

Any thoughts welcome.

Thanks,

Dave

This should probably have been posted as a new thread, but I'm not able to create a new thread. Probably because I'm a new user on this forum.

I'm planning a build of the cyclone, but have had trouble locating a suitable trashcan. I've found no suitable trashcans in locally.

I had been thinking of using an empty oil barrel. But I guess those are a bit too heavy to move around for emptying.

I've now found the Brute trashcan online. As many people seem to use this trashcan, I have a question for you.

Can someone who has either the 55 gallon or 44 gallon version please measure the outside diameter of the trashcan?

I ask because I need to know the outside dimensions before ordering. I need to make sure it is smaller than the door opening to the room where my dust collector is.

I found the following info on the web, but it doesn't say if the measurements are taken on the inside or the outside:
55 gal  208.2 L
Diameter:   26.4 in     67.0 cm
Height:     33.2 in     84.3 cm
   
44 gal  166.6 L
Diameter:   24.0 in     61.0 cm
Height:     31.5 in     80.0 cm
                               
32 gal  121.1 L
Diameter:   21.9 in     55.7 cm
Height:     27.8 in     70.5 cm

The largest one will probably not fit through the door opening.  I hope the 44 gallon one will fit.

I'll build a 6" separator. I think both the 32, 44 and 55 gallon trashcans are large enough for this. I read, somewhere, that the minimum diameter should be inlet size * 3. For me that would be 6" * 3 = 18". All of the trashcans are larger than this (assuming the measurements are the inside diameters).

Can this be scaled up to 48 inch diameter with a twenty inch inlet, and still work ok?

Quote from: bennybmn on September 11, 2009, 05:36:52 PM
My shop vac filter is pretty well caked too.... I use it primarily for cleaning the shop floor, and for my palm and RO sanders, so LOTS of fines get sucked up. I'm thinking a smaller diameter separator could help.

I switched to a 5 gal bucket for the separator section to keep the air velocity up.  So far it seems to work better,  But experience is limited,

These systems always run by applying a vacuum. Can anyone tell me if the reverse is applicable?
Can you run the powered exhaust from a DeWalt 735 thickness planer into this system?  With, or without using something like an enhanced Harbor Freight collector?

Quote from: deancrozon on February 12, 2017, 11:44:40 AM
Can this be scaled up to 48 inch diameter with a twenty inch inlet, and still work ok?

Dean -
I can't imagine why you haven't had many responses to your request!  ;)
If you browse through the posts about building a Separator, you will find that a 5hp system is huge among our builders.   :o
I have a very large one ahead of a 20hp bag house.  But it has a 14" duct and should have been scaled smaller to be more effective.  I can't calculate how much horsepower you would need to drive such an enormous air mass at a speed fast enough to create the centripedal force to pull clean air out without debris. 

If you have a system that is that big, I have two suggestions:  8) You need a professional engineer to get the benefit out of such a large system; Or, you need to make smaller subsystems closer to the source of your debris generation. 

Otherwise,  Good Luck!  :D

Quote from: retired5 on February 17, 2018, 06:53:36 PM
These systems always run by applying a vacuum. Can anyone tell me if the reverse is applicable?
Can you run the powered exhaust from a DeWalt 735 thickness planer into this system?  With, or without using something like an enhanced Harbor Freight collector?

Yes!
Use the Search function and you will find at least one system for the Dewalt planer that does not use an external blower - just the planer's internal blower. Here is a good one:
http://www.jpthien.com/smf/index.php?topic=809.msg4539#msg4539 (http://www.jpthien.com/smf/index.php?topic=809.msg4539#msg4539)

OK

Built my lid for a 32 gallon galvanized trash can.

Testing yielded the following:

10 gallon volume of  dust, shavings and chips in the can; 3 cups of dust in the plastic bag of my ShopFox...

Used a new bag and felt for the test. 4" Hoses.

Ran the following:

14" Bandsaw
10" Cabinet saw
13" Planer
Router Table
8" Jointer

Handled everything perfectly.

I have a Harbor Freight dust collection system that I wish to modify with a Thien baffle.  I plan on using a 31 gallon galvanized garbage can for the dust collection system using the lid with holes cut into it to fit the inlet and outlet.  My question is should there be a distance between the bottom of the inlet elbow to the baffle or should it be resting on the baffle.  It would seem there should be separation from the bottom of the elbow inlet to the baffle to allow air to circulate around/below it.  Thanks.

@rosenw - FYI - Probably best to start a new thread when asking a question, even if the question is frequently asked.

You are correct, consensus seems to say there ought to be enough clearance between the bottom of the inlet's elbow and the top surface of the baffle to allow the chips to fly without getting hung up between.