Thien Dust Separator - tablesaw test

[@Davospace1]

Thanks for the vid. You've just given me the confidence to build one myself. I couldnt work out how I was going to do the cone part and now I find that it's not necessary at all :-)

[@dyc9124]

Cone part for a cyclone. This a Thien baffle.

[@moonolyth]

Great good to see it working for designed factor. You may be able to heat and bend the elbow so you can direct it closer to the wall and narrow the air, again nearer the wall as the pipe would be flatter.

[@johnisnot]

Note that you aren't seeing *air* going down into the slot, just debris... The bulk flow of the air is all above the plate, with mixing at the slot due to turbulence.

[@randsipe224]

I knew from experience mine was working extremely well but it’s fun to see it live.

[@johnisnot]

It works great with my "lunchbox" style thickness planer. I even vacuum up handplane shavings with it when I clean the shop. Sometimes a long wispy shaving will get tangled around one of the threaded rods that holds it together, but it has no problem separating larger material from the airflow. Using the planer, I actually filled up the collection barrel, and half filled the top separator, and still nothing went through.

[@Gidjoiner]

Hi, finally found a container suitable to make one of these, experimenting a bit for now but cobbled together a quick version of yours this Sunday afternoon & i was very surprised at how good it worked, Thanks seeing your see-through version has inspired me to build one in the first place & now I'll take it further, :-) ps I've put a crappy vid on my channel to show :-)

[@1AXMRDR]

I realize that this video is old but the visual it provides is very cool. I built a larger diameter version similar to this but did not include the lower baffle. The cavity is around 30" tall and works perfectly. By not having a lower baffle the time is extended for the debris to sling out and 'settle'. If you still have this unit give that a try.

[@johnisnot]

I think the baffle helps prevent finer dust from being picked up again once it's settled into the lower container, but I don't think it helps at all with initial separation. A little height in the upper section is helpful for settling, as you suggest. I do still have this unit, and even though I thought it would be a prototype when I put it together, it works so well I don't really see the need to do another version, although I probably will one day as an experiment.

[@johnisnot]

I'm *very* sure you don't want the outlet below the plate. The idea is that the area down below has low air velocity, so that lighter particles stay put. This is just a simple cyclone separator, except instead of a long cone to separate the collection barrel from the moving air, it just has a flat plate. The physics are pretty well worked out, and the air basically spirals toward the central outlet like a whirlpool in a bathtub. You can visualize it when long (eg. handplane) shavings get in.

I knew how they work, but I've never seen a transparent one. Very interesting! :D Thanks for sharing!

[@sampark1922]

The Baffle could be rotated clockwise about 30 degrees, so that the pile on the far side doesn’t form. You can see in your setup, the flow of dust going around 1 full time and more landing on that side.

[@johnisnot]

It's just a flat piece of 1/16" thick polycarbonate, about 9 inches x 40 inches, rolled into a short tube. It's very flexible.

[@johnisnot]

I don't know. I haven't compared, and the answer depends on your criteria. For particles as big or larger than fairly fine sawdust, I don't think there's anything better because I've seen zero of that stuff get through. For very fine dust, some other cyclone design might be better, but I don't think any cyclone is good enough to capture the really tiny particles that are hazardous from a health perspective.

[@carmelpule6954]

It is quite impressive for a demonstration of the dynamics both those favourably required and those that shows imperfections. The input bend rear part offers a rather big obstruction and deflection for the swirl and there is a location where the change of momentum on hitting the rear of the band will cause some particles to be sucked up after bouncing off it. Also please do not underestimate the turbulence generated by those innocent looking three vertical rods , they are not as innocent as they look and they could have been installed on the outside rather than the inside, Also the flat face on the rear end of the slot is causing turbulence and the rotation is forming a little hill at some distance after the end of the slot, That flat part at the end of the slot could have been flared much more efficiently to incoming flow. I think that instead of the bend one could have used a straight pipe coming in through the top at a gradual angle and so the swirl would not have anything to hit on full circulation. Flow dynamics are so fascinating.

[@johnisnot]

+Carmel Pule' Good points. One of these days I'll fabricate a new one with it's own integrated side inlet. I like your idea about putting the three rods on the outside. I'm not so sure about the sloping inlet pipe from the top though. That would blow against the plate and stir up things that are trying to settle into the gap.

[@timduncan9835]

Carmel Pule' m

[@rjbiz9120]

Yep I get

[@marichari5637]

Carmel Pule' 7

[@marichari5637]

Carmel Pule' - Demerit revere3 3

[@johnisnot]

Well, a mixture of air molecules and tiny wood bits comes out the end of that bent pipe on the left at about 2.5 meters / sec. Those particles want to keep going straight (Newton's 1st) but we get a separation effect because the mixture hits the curved plastic surface and the air is deflected more easily than the wood particles.

[@dustextraction3589]

Dust is very harmful for health. Very well demonstrated video on cleaning of all dust and debris accumulated in table saw cabinet.

[@riverdobsonwallace]

Excellent! All it need now is a pleated filter at the top of the build.

[@johnisnot]

Google "thien separator". The incomplete slot around the outside is part of the design. I haven't tested it myself, but the idea is that the plate decouples the airflow above and below, preventing the collected debris from being picked up again.

[@JackWilson327]

Nice video! That pretty much clears it up for me! LOL! Seriously, I think this is the way to go.

[@UberAlphaSirus]

Thanks for the upload. seems to catch just as good as the cyclone shape ones. Nobody is going to win on the fine fine dust, so lets all give up and have a fine filter for that. I was thinking, seeing these are based on velocity and vacuum and gravity. Gravity seems to work on this fine. what would happen if you had the vacuum end a bit higher and just behind the input pointing opposite to the debris end with a slight tilt to aid gravity. Faster spin perhaps but less center vacuum.

[@johnisnot]

I did try installing another baffle, held up on the all-thread, mounted just below the inlet elbow. I was interested in seeing what was happening above and below the plate, and thought maybe it would provide even better isolation between the upper airflow and the collection can. Bottom line is it worked better without that plate, and I think a little distance is a good thing - it just makes the unit a little taller.

[@ядриломудрило]

А если прикрепить к различным местам ниточки, то можно будет видеть распределение направления движения воздуха внутри объёма..

[@Gidjoiner]

Hi do you think this would work ok with thicker material from a thicknesser,like small shavings, would the slot to the collection area be big enough? all the demonstrations concentrate on finer dusty particles. Prob gonna try building one anyway but as you already have a clear one it'd nice to know Thanks.

[@1873Winchester]

Looking at the dust spiral, I wonder if you could achieve better efficiency by rotating the baffle a bit clockwise. Looks like there's a little bit on the end that misses going down into the dustbin.

[@Gidjoiner]

Thanks

[@LeosTueftelei]

Excellent work !

[@freshpootube]

That 90 degree bend for the inlet seems to work great. Lots of other versions, people go to great lengths to create a curved angled inlet on the outside of the cylinder. This shows it may not be necessary?

[@johnisnot]

I definitely don't think it's necessary from a separation perspective, although fewer elbows = less friction = more volume = better dust collection. I plan to build a side-inlet version... someday when I'm bored.

[@freshpootube]

Mathias Wandell was experimenting with a side entry one he's built and (I think) he found he actually got better performance by introducing some turbulence. Yours works great.

[@Bobbyl007]

I was wondering if you had done any experiments with the spacing between the collector cover and the baffle. I've notice Thein and several others have the cover and baffle much closer together than your design. If you have was there any difference in fine particulate efficiency?

[@DistrictWoodworking]

Great job, How did you get the plastic from a sheet to be a circle?

[@rcdc128]

I was waiting for a finger to funnel itself through there XD

[@stephboeker7835]

What is the clear plastic tube you're using?

[@Bue2]

Does it seem to work better than deeper, conical versions?

[@projectlemming3496]

Does it matter what direction the cyclone spins? Does the height of the box have an impact?

[@johnisnot]

+Project Lemming No, it doesn't matter which direction it spins, unless you're in Australia where the coriolis force means it has to go the same way your toilet works. Just kidding. It doesn't matter. The height does have an impact. I put a second baffle in to make it shorter at one point, and it was not as effective, but I haven't tried to optimize it. I think having some clear space below the inlet elbow and above the plate is a good thing. The elbow hanging down makes the flow turbulent which mixes up the dust you're trying to separate. Probably, taller is better within reason. The baffle just defines a break between the spinning separator portion and the non-spinning collection bucket.

[@marichari5637]

Project Lemming - Demerit 2

[@marichari5637]

Project Lemming - Demerit l

[@jsteifel]

Whats the name of the second 2 motor extractor?

[@paulmanno5679]

How did you bend the plexiglass?

[@paulmanno5679]

+Paul Manno Nevermind! Reading the blog...

[@gfw1973]

Does anyone know if a Thien baffle will still work if the airflow is pushed into it vs sucked out of it? My planer exhausts it's own chips. If I were able bodied I'd simply build one and see, but I'm disabled and building things is difficult so looking for input and/or experience with this. Also any 'bad' design flaws to avoid? Thanks

[@dlwatib]

George Woodworth It shouldn't matter. What you need is a lower pressure at the outlet than the inlet, and it doesn't matter how you generate that pressure difference: compression on the inlet side or vacuum on the outlet side, or even a combination of the two.

[@gfw1973]

Thank you very much for the info

[@johnisnot]

dlwatib True, although I would try to not to have the inside of any filtration system at a higher pressure than the surrounding space for a couple of reasons. 1. contaminants inside want out - any little crack will spew dust in this case. 2. You'll have to fasten everything together much better. When the inside is under vacuum, it pulls all the joints together with quite a bit of force. My separator is just sitting on the trash can, with no mechanical attachment. If it were pressurized (like from the outlet of a planer) it would require some buckles or something to hold the top on, because it definitely won't function right if you get leaks in the lower collection chamber. In industrial systems, you always have all dirty airflow under suction for as much of the system as possible, so that even if there is a leak, it's just clean air leaking into the collection system, instead of dirty whatever blowing out for workers to breathe.

[@Kekec_Sun]

If you would push air into input port hard enough adding any consistent material that is not in form of dust into it through input port and if it would have small opening at the center of the bottom and inserted tube with opened ends at the top, the input material would be shredded to dust falling out of the bottom hole. At the top hot air and water vapor would escape.

[@jjs24h]

Entrance for top is bad