Experiment #1, Test 1
Not sure exactly what caused my first trial to pretty much utterly fail. I suspect that the hand plane shavings should never have been included while vacuuming the mess up off of my shop floor which has been building up since when I first started work on this endeavor, having the vacuum in various dissembled states. Still, maximum sized chips needed to be tested. These were normal size shavings from a 2" cutting iron that created a major clog and was part of this experimental first running of the Thien Separator that I designed to fit into my 32-year old shop vac - Sears Model No. 113.178081, should you care about such details. More details are shown in the attached drawings and photos.
Placing the completed Thien Separator assembly into the 16-gallon plastic barrel and aligning the vacuum head with its integral intake port and the 2" PVC fitting required some attention, but fit perfectly. By studying the dust pattern around this connection, there is evidence that the seal between the PVC fitting and the molded plastic lid was good. Likewise the weather stripping seals on both the top and bottom of the 9" x 2" filter did their job. Also, the filter did its job as it was quite packed with dust in the creases of the filter's paper folds. Soundly rapping the filter against the inside of the barrel loosened most of the debris but not all of it; I'll need to find somebody that has an air compressor and try blowing the rest of it out before Experiment #1, Test2.
If the schematic is an accurate representation or your build, then it is pretty obvious why you had a major failure. If the inlet elbow sits against or even close to the baffle, the shavings will quickly pile up behind that elbow and cause a clog. The photo of your "major" clog tends to confirm that assessment, there is a pile of shavings clogged up behind the elbow. There needs to be space between that elbow and the separator floor (baffle) to allow shavings to circulate until they are removed by the drop slot.
Quote from: retired2 on June 16, 2020, 09:58:41 AM
There needs to be space between that elbow and the separator floor (baffle) to allow shavings to circulate until they are removed by the drop slot.
@retired2
Not sure if Phil is AWOL, but I'll just let his photos offer another opinion
(http://www.jpthien.com/graphics/cypro3.jpg)
(http://www.jpthien.com/graphics/cypro2.jpg)
Your design will work with smaller waste but not planer shavings. Your not the first person to discover this problem, it has been discussed more than once.
Experiment #1, Test 2
By overtly not including shavings from my Millers Falls 14B hand plane (similar to a Stanley No. 5), and only vacuuming the debris beneath the table saw, Test 2 results were much more encouraging. Principally made up of wood fibers, the sawdust also includes a little bit of chips from PVC pipe and sheet. There were no clogs; however, an appreciable number of fines did escape the baffle and get trapped by the filter above the baffle. What remains to be seen is using this as a normal shop vacuum and under the present configuration of Experiment #1: how frequently the filter will need to be cleaned. Oh and by the way, those hand plane shavings also bollixed up the original, pre-Thien Separator vacuum setup ;)
What many people have done to avoid rebuilding their separator is just take a slice off the bottom of the elbow. Run it through your band saw if you?ve got one. Start with a small slice and keep increasing it till it works.
Oh, another thing I think is troublesome are the spoked ribs under your baffle. The air under the baffle should spin smoothly. The spokes create turbulence that could adversely effect the performance of the drop slot.
Hi retired2,
Thank you for your suggestions. Could you post a photo of what the underside of your baffle looks like without disturbing the dust patterns?
I'm not absolutely sure, but it doesn't look like Phil needed to slice off the bottom of the PVC fitting as it appears to be in full contact with the bottom of the baffle:
(http://www.jpthien.com/graphics/cypro3.jpg)
Experiment #1, Test 2 results did not indicate there to be anything fetched up at the bottom of the PVC fitting, just a little dangling from the edge of the drop slot. See photo (http://www.jpthien.com/smf/index.php?action=dlattach;topic=1368.0;attach=3689)
http://www.jpthien.com/smf/index.php?topic=563.0
You are too focused on the photo of Phil?s early separator. People don?t typically build shop vac separators for planer applications. Attached to a planer, Phil?s separator would clog just like yours. Top hat designs were developed because they solve remove the inlet pipe from the waste stream. I?m sure Phil would be giving you the same advice I have.
Quote from: retired2 on June 16, 2020, 04:10:29 PM
http://www.jpthien.com/smf/index.php?topic=563.0
Thanks for the link to that thread which I have read in its entirety already; however, I don't recall a single image of the bottom of your separator showing any dust patterns.
Quote from: retired2 on June 16, 2020, 04:10:29 PM
You are too focused on the photo of Phil?s early separator. People don?t typically build shop vac separators for planer applications. Attached to a planer, Phil?s separator would clog just like yours. Top hat designs were developed because they solve remove the inlet pipe from the waste stream. I?m sure Phil would be giving you the same advice I have.
Who said I had a planer? I don't own one yet, though if I ever do, the Dewalt DW735 sounds like the way to go.
Here's two of the hand planes that I frequently use since earlier this winter:
(https://woodbarter.com/attachments/refurbished-img_20200123_082546-jpg.188728/)
I thought you asked for a photo of the underside of my baffle? That photo is in the first group of construction photos in the link I sent you.
The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference. In fact, the shavings from a hand plane are probably worse.
Quote from: retired2 on June 16, 2020, 05:51:24 PM
I thought you asked for a photo of the underside of my baffle?
Sorry, I wasn't clear. I'm curious about the dust patterns on the underside of the baffle after it's been in use, not prior. I am interested in seeing what they look like on your top hat version.
Quote from: retired2 on June 16, 2020, 05:51:24 PM
The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference. In fact, the shavings from a hand plane are probably worse.
Agreed. I just wasn't seriously planning on hooking up an intake hose connected to my Stanley No. 4 hand plane; however, that said, I must confess of staging something akin to that as a cartoon of sorts! LOL ;D
Experiment #1, Test 3
This test centered in particular on mitigation of turbulence beneath the baffle by covering the support brackets in shrink wrap film. And to much delight, the impact was most noticeable.
One sidebar note, the baffle fits extremely well in the barrel making its removal a little tricky, so much so, that the birch drawer pulls that were originally screwed onto the threaded rods finally just could not hold their threads. Thus, the new metal knobs which had to be re-drilled and tapped to accommodate the #10-24 rods. Works quite well!
Quote from: retired2 on June 16, 2020, 04:10:29 PM
Top hat designs were developed because they solve remove the inlet pipe from the waste stream.
Yes, I get that, and look forward to one day possibly trying to make such a version of the Thien Separator, and with many thanks to yours, and others, work on them.
My original intent was to see if I could, albeit in this crude fashion, introduce this concept of particle separation wholly contained within a regular shop vac. I'm still puzzled greatly by the fact that none of the shop vac manufacturers have not made, at least to my knowledge, a shop vac that incorporates a Thien style separator, or some other means of cyclonic separation. I've written to Dyson, but from their response, gave the impression that they weren't interested in the wood workers' niche, nor in the development of a small self contained vacuum system designed for the small wood working shop. Imagine a highly efficient and powerful Dyson hanging off the back of your bandsaw, or neatly tucked behind your lathe, table saw, etc. The need for elaborate and expensive dust collection systems with pipes and hose run everywhere, up one side and down the other, could all be eliminated. This is what I liked about Hector's neat and modest custom setup under his table saw.
Shop vacs (and Dysons) have high static pressure and low volume. Dust Collectors, by comparison have low static pressure and high volume. Sometimes the ideal solution is both, but there are many tools and machining operations that a shop vac and its low CFM will just not do the job.
Quote from: Kelly Bellis on June 16, 2020, 06:01:49 PM
Quote from: retired2 on June 16, 2020, 05:51:24 PM
I thought you asked for a photo of the underside of my baffle?
Sorry, I wasn't clear. I'm curious about the dust patterns on the underside of the baffle after it's been in use, not prior. I am interested in seeing what they look like on your top hat version.
Never had a reason to look. I'm more interested in seeing what is in the waste drum.
Quote from: Kelly Bellis on June 16, 2020, 06:04:39 PM
Quote from: retired2 on June 16, 2020, 05:51:24 PM
The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference. In fact, the shavings from a hand plane are probably worse.
Agreed. I just wasn't seriously planning on hooking up an intake hose connected to my Stanley No. 4 hand plane; however, that said, I must confess of staging something akin to that as a cartoon of sorts! LOL ;D
I assumed you were going to vacuum the shavings from the floor and your workbench. If not, I'm not sure why you are testing your separator with that kind of waste..
Your last set of photos that includes the one "continued fetch......" should be all the evidence you need to trim off some of the bottom of the inlet elbow. There is still waste accumulating there, and that is how clogs start. That elbow causes turbulance even before clogs start, but attached waste makes it worse. So, with the end of the drop slot just behind this turbulance it is not surprising that waste would start clinging to the end of the drop slot. None of you photos give me a good view of the ends of the drop slots, but from what I can see they are pretty blunt. The should be nicely rounded looking down on them and then the top and bottom surfaces should be rounded at the end of the slot, not sharp corners anywhere.
Quote from: retired2 on June 16, 2020, 08:05:44 PM
None of you photos give me a good view of the ends of the drop slots, but from what I can see they are pretty blunt. The should be nicely rounded looking down on them and then the top and bottom surfaces should be rounded at the end of the slot, not sharp corners anywhere.
Last, before turning out the lights, and before hearing back from you, I modified the end of the drop slot which had only been filleted (0.25r). I'll let you know how Experiment #1, Test 4 goes. For the time being, at the beginning of the drop slot I'll leave as is; i.e., filleted only without further change.
Quote from: retired2 on June 16, 2020, 07:48:51 PM
Quote from: Kelly Bellis on June 16, 2020, 06:01:49 PM
Quote from: retired2 on June 16, 2020, 05:51:24 PM
I thought you asked for a photo of the underside of my baffle?
Sorry, I wasn't clear. I'm curious about the dust patterns on the underside of the baffle after it's been in use, not prior. I am interested in seeing what they look like on your top hat version.
Never had a reason to look. I'm more interested in seeing what is in the waste drum.
Well, thanks for considering my request anyway.
The purpose of Test 1 and the inclusion of the whisper thin shavings was simply to what would happen; just for the science and fun of it.
Quote from: retired2 on June 16, 2020, 07:52:30 PM
Quote from: Kelly Bellis on June 16, 2020, 06:04:39 PM
Quote from: retired2 on June 16, 2020, 05:51:24 PM
The shavings from a hand plane and a power planer have the same problematic features, and separators don't know the difference. In fact, the shavings from a hand plane are probably worse.
Agreed. I just wasn't seriously planning on hooking up an intake hose connected to my Stanley No. 4 hand plane; however, that said, I must confess of staging something akin to that as a cartoon of sorts! LOL ;D
I assumed you were going to vacuum the shavings from the floor and your workbench. If not, I'm not sure why you are testing your separator with that kind of waste..
Quote from: retired2 on June 16, 2020, 07:46:42 PM
Shop vacs (and Dysons) have high static pressure and low volume. Dust Collectors, by comparison have low static pressure and high volume. Sometimes the ideal solution is both, but there are many tools and machining operations that a shop vac and its low CFM will just not do the job.
I agree with you on that, and I may simply have to bite the bullet and buy a big dust collection system some day. My primary goal of integrating a Thien Separator into my Craftsman shop vac is to see if doing so will improve its performance and reduce the number of times that I need to clean the filter. If I'm able to use it in conjunction with my table saw and bandsaw, then that will be great! And I won't have to buy a big dust collection system.
Quote from: Kelly Bellis on June 17, 2020, 04:55:40 AM
Quote from: retired2 on June 16, 2020, 07:48:51 PM
Quote from: Kelly Bellis on June 16, 2020, 06:01:49 PM
Quote from: retired2 on June 16, 2020, 05:51:24 PM
I thought you asked for a photo of the underside of my baffle?
Sorry, I wasn't clear. I'm curious about the dust patterns on the underside of the baffle after it's been in use, not prior. I am interested in seeing what they look like on your top hat version.
Never had a reason to look. I'm more interested in seeing what is in the waste drum.
Well, thanks for considering my request anyway.
The underside of my baffle is not in plain view even whenI pull the waste drum out for emptying. I need to get down on my knees and look up with a flash light. At age 75, I don?t do that unless there is a reason to, but next time I empty the drum, I?ll look. Not sure how long that will be since I am not doing work in the shop these days due to unrelated medical treatments.
That's okay, don't give it another thought. I appreciate your response, thanks.
Experiment #1, Test 4
The terminus of the drop slot was modified to provide a 20? bevel, tempered with a liberal soaking of CA glue and allowed to fully cure over night. Also, the tiny nub at the foot of the PVC fitting was sanded off. Test 4 also ran a little longer, sucking up more of the contents on the sawdust box than in previous tests which revealed 1) an interesting looking sawdust strata from past projects, and 2) unfortunately a greater amount of debris that made its way to the filter. All of which has me thinking of returning to the drawing board before conducting Test 5.
Throughout these past four tests, small, but noticeable charges of static electricity has been observed. For example, the dust patterns displayed, or when I placed my hand into the barrel right after conducting the test, the wood chips are attracted to my fingers like iron filings to a magnet. This leads to the question: what role, if any, does static play in keeping small particles afloat? Just a thought. I believe that these charges are created by the plastic barrel being continuously rubbed by the wood bits and pieces.
I would not recommend beveling the end of the drop slot, knife-like edges grab waste material and hang on to it. This is where clogs start. I would recommend you round-over the learning edge and make it as smooth as you can.
And if you are really interested in improving the performance of that separator, cut a slice off that inlet elbow and get on with it!
Quote from: retired2 on June 17, 2020, 02:17:51 PM
And if you are really interested in improving the performance of that separator, cut a slice off that inlet elbow and get on with it!
Nothing is being caught under the pipe r2, so why cut the pipe?
Alternatively, would increasing the height between the pipe bottom and the lower disc be satisfactory, say by 0.5"?
Quote from: retired2 on June 17, 2020, 02:17:51 PM
I would not recommend beveling the end of the drop slot, knife-like edges grab waste material and hang on to it. This is where clogs start. I would recommend you round-over the learning edge and make it as smooth as you can.
Okay, thanks. I'll try that on the next one presently still in design.
Quote from: phil (admin) on November 25, 2007, 03:10:54 PM
... the 120-degree portion starts back at the bend of the elbow. So the particle travels along all but approx. 2" of the 120-degree portion. I found this design worked best to reduce turbulence at this critical point.
D'oh! I missed this earlier. I'll definitely include this design criteria for my next go at it! Thanks Phil!!
r2 - I found this nugget from Phil.
Quote from: phil (admin) on July 16, 2009, 06:43:12 AM
Leaving some room between the elbow and the baffle will prevent dust from packing in between the two. 1/2" to 1" is sufficient, depending on the type of materials you work with (softer pine, with stringy shavings, needs a little more room so I'd go 1" if you work with a lot of it).
Quote from: Kelly Bellis on June 17, 2020, 03:15:50 PM
Quote from: retired2 on June 17, 2020, 02:17:51 PM
And if you are really interested in improving the performance of that separator, cut a slice off that inlet elbow and get on with it!
Nothing is being caught under the pipe r2, so why cut the pipe?
Alternatively, would increasing the height between the pipe bottom and the lower disc be satisfactory, say by 0.5"?
Raise the pipe or slice it off, either works. And you do it not just to eliminate clogs, but to help smooth out the air stream.
Quote from: Kelly Bellis on June 17, 2020, 03:37:17 PM
Quote from: phil (admin) on November 25, 2007, 03:10:54 PM
... the 120-degree portion starts back at the bend of the elbow. So the particle travels along all but approx. 2" of the 120-degree portion. I found this design worked best to reduce turbulence at this critical point.
D'oh! I missed this earlier. I'll definitely include this design criteria for my next go at it! Thanks Phil!!
Now that I start to try and draw this, I'm less certain what you meant here Phil. Is the drawing below in agreement with what you meant?
@Phil - Alternatively, and what I had to begin with was the drop slot terminus coincident with the centerline of the vertical axis of the elbow, as seen here:
Funny Story
Test 5's new lower baffle was laid out, drilled, and on the router jig when I heard back from Phil with his answer to go with A in regards to the drop slot terminus question posted above. Because of the drilled hole's location for the router bit, I couldn't quite get it to A's position, but got it as close as I could ::)
Experiment #1, Test Series all have a straight pipe outlet. Experiment #2, still only in the planning stages, will feature the bell mouth style outlet. The geometry for the elliptical bell mouth pipe, plus the design criteria of its vertical position, plus retired2's comment of increasing the height between the bottom of the inlet pipe and the lower baffle, then all contributed to Experiment #1, Test 5. Also seen in Test 5 besides an increased gap between upper and lower baffles: no support brackets beneath the lower baffle; three spacers separating upper and lower baffles instead of 6; and lastly, lower profile wooden knobs with embedded nuts. The knobs are a critical bit of kit as the upper baffle sits quite snugly in the plastic barrel when properly seated along its scribed line.
Experiment #1, Test 5
After vacuuming up the dust from using the router on the hardboard and other operations, I went back to the box under the table saw still quite full of saw dust; maybe five minutes in total of vacuuming. The results weren't as pretty as was hoped and tend to suggest that the lower baffle was not being held stationary with its 120? edge tight against the barrel. This may possibly be attributed to the amount of flex observed in the assembled structure in spite of efforts which included epoxying the threaded rods to the lower baffle and snugly tightening the nuts on the three spacers.
I did not take the time to look at your dimensional information, but don?t be surprised if the bellmouth results in more by-pass. I have often cautioned about the use of bellmouths in small diameter separators. The flange brings the exhaust air stream much closer to the circulating waste stream and picks up waste before it has separated out. This advice has always been given to top hat builders, but I think it is still valid for your application as well.
Thanks r2. If I get that far with these tests, I'll not be surprised, but so far, all of my tests have indicated that getting the same kind of performance that users of the trash can lid type Thien Separator get (with a straight pipe) is difficult, at best.
One element that's potentially exacerbating my efforts of getting the Thien Separator inside the Craftsman shop vac to perform well is static electricity. It isn't a large quantity, but it has been consistently present in all five tests so far.
Home Depot was out of the regular variety of hardboard, but had in stock what is known as Eucatile and is made in Brazil. I bought a 4' x 8' sheet and that's the type of hardboard that I've been using. "Eucatile is a scored surface melamine based and infra-red cured top coated hardboard" according to the manufacturer, Eucatex (http://eucatex-antigo.aatb.com.br/en/hardboard/product?id=138).
After the vigorous scrubbing over the melamine surface, then there is the plastic barrel's walls being rubbed against at high velocity. I couldn't find an HDPE stamp or any other indicator on the barrel, but am guessing that it some form of high density polyethylene.
I do not know how much of an effect any of this has, but it is none the less observable and worth mentioning.
Here's the label that's on the back of the sheet:
I can?t help you with the static cling. I get a little fine dust that clings to the plexiglass walls of my separator, but in operation the static has no effect. If anything, the circulating waste stream keeps the walls from accumulating anything but the finest dust.
For now, I've called a truce with the sawdust having just now reassembled the Sear Craftsman Wet Dry Vac Model No. 113.1768081 back to its original configuration. I'm not admitting defeat, just that the saw dust has been smarter than me in this little dust up that's been going on for the past two weeks.
I've ordered the Dewalt DW735X planer with its much celebrated chip ejector and I plan to build a Thien Separator for it, though I'm thinking maybe of using sheet metal for the inside walls instead of clear polycarbonate or acrylic.
Don?t underestimate the value of clear walls, it is much more than a novelty, unless of course you put the whole thing in a soundproofed enclosure..
Quote from: phil (admin) on November 25, 2007, 02:55:30 PM
There is another reason to avoid plastic pails, though. And that is to avoid static problems. I'm not concerned with the chance of explosion, but rather have noticed that static charged plastic can interfere with the operation of the cyclone.
Amen.
Without any dimensions, I can't really tell, but it appears that you have built down into the collection area of the bucket (bottom) so deeply with the separator, the vortex doesn't have sufficient room to slow and drop the debris below the baffle. My guess is the airstream is moving the waste through the slot and then picking it up again on the way to the filter - scrubbing. It's the reason most waste containers with separators sitting on them, have to be emptied about 1/2 to 3/4 full.
Quote from: 1Architect on July 18, 2020, 05:38:57 PM
Without any dimensions, I can't really tell ...
The dimensions are provided in the original post.
Quote from: 1Architect on July 18, 2020, 05:38:57 PM
it appears that you have built down into the collection area of the bucket (bottom) so deeply with the separator, the vortex doesn't have sufficient room to slow and drop the debris below the baffle. My guess is the airstream is moving the waste through the slot and then picking it up again on the way to the filter - scrubbing. It's the reason most waste containers with separators sitting on them, have to be emptied about 1/2 to 3/4 full.
Yes, building the separator in the bucket was the whole idea from the beginning. The depth into which the separator descends is illustrated and the related dimensions are given in the original post.
Static electricity was created by the high velocity particle stream rubbing on the plastic barrel and because there isn't an easy way to run a ground to Earth with this particular variety of vacuum, I abandoned the original idea of incorporating a Thien Separator into the Craftsman 16-gallon shop vacuum. The vacuum was returned back to it's regular duties with the bonus of having gotten a super duper cleaning from top to bottom, plus a new KoPach Filter - https://www.kopachfilter.com/ which fits perfectly! I also splurged in getting a Filterpal bag and am so glad I did as the combination has been exceptional over the past month or so of daily use.
I scaled the depth under your baffle and it appears to be about 9". When you used it to suck up a modest pile of shavings and dust, all of a sudden you have reduced the working space to 7" or less. From your previous pictures, it looked like there was at least 2" of debris in you bucket. In any case, it doesn't leave much "working" room for the vortex to loose speed, drop the debris, leave it there (!), and return to the baffle chamber.
I built my Top Hat separator with lots of view panels to see what is happening. One looks into the 20" deep waste container under the baffle. I am certainly not comparing my separator to yours, but in mine, I can see a serious storm occurring in my waste can under the baffle - even when no dust is being picked up, just running! I can certainly see why scrubbing occurs when the surface level of the debris climbs to half full or so.
Glad you renewed the life of your original shop vac. I don't have a fancy bag for my shop vac filter, but a few years ago, I swiped an older pair of panty hose from the boss, and from a one of the legs, cut a section, and stretched it over the filter. It worked surprisingly well, but certainly not like your fancy bag. With the hose in place, just pinch a section of the stretchy fabric, pull it away and let it "pop" back in place. The dust falls away. I was impressed, the boss wasn't.
I am curious. In your last post, you introduced a static electricity problem with the plastic waste can, when the shop vac was used as a separator. Do you not currently have the same static electricity, when currently used as a normal shop vac?
Yes, that is correct, the static charge was only present when the waste stream in the Thien Separator cyclonically rubbed the plastic barrel. Most interesting was how long the charge was held.
(http://www.jpthien.com/smf/index.php?action=dlattach;topic=1368.0;attach=3767;image)
(http://www.jpthien.com/smf/index.php?action=dlattach;topic=1368.0;attach=3769;image)
Your statement made me think... (rare).
You said, "Yes, that is correct, the static charge was only present when the waste stream in the Thien Separator cyclonically rubbed the plastic barrel."
My question became, using your shop vac in normal mode, doesn't the debris still cyclonically rub against the plastic barrel? Why doesn't the plastic barrel still get charged? And then, maybe it doesn't rub cyclonically!
So, using your existing shop vac in normal mode, if you deflected (turned 90 deg) the stream of air entering the plastic barrel so that it was directed along a wall, instead of just pouring straight into the plastic barrel, wouldn't that set up a vortex in the plastic barrel that would be similar to a separator? Just think of a separator without a baffle.
Centrifugal force would pull the larger pieces to the wall and gravity would pull them down... Let's see... a piece of cardboard and some duct tape will make a dandy deflector.
But it is possible the space in the plastic barrel may be so tight, the airstream speed is to great, and the larger debris won't fall out of the stream. You never know.
The stock inlet for the 16-gallon Sears Craftsman wet-dry vac (113.178081) bifurcates the debris stream upon entry into the main collection barrel and as such doesn't form a coherent air stream, cyclonic of otherwise. Attached are a couple of shots from early June when I entirely disassembled the vacuum, washed all of the plastic parts and cleaned the motor assembly.
"Bifurcated" is a new word to me. Sounds naughty, or maybe something you do after eating too many hot dogs.
OK, forget the cardboard and tape and the deflector in my previous post. It's even simpler now. If you put a cap over one of the bifurcated inlets, the remaining inlet would create a vortex, would it not? However, I suppose that would change your Bifurcating vac into a furcating vac!
Seems the Bifurcation is aiming one airstream at another and destroying any possibility of a vortex. Just for fun, why not try plugging up one inlet and seeing if the vortex develops and some of the larger particles are separated. I would guess only you will be able to tell the difference, if any.