The Thien Separator Inside A Craftsman Wet Dry Vac

[retired2]

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.

[retired2]

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.

[retired2]

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..

[retired2]

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.

[Kelly Bellis]

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.

[Kelly Bellis]

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.

[Kelly Bellis]

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.

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..

[Kelly Bellis]

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.

[retired2]

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.

[Kelly Bellis]

That's okay, don't give it another thought. I appreciate your response, thanks.

[Kelly Bellis]

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.

[retired2]

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!

[Kelly Bellis]

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"?

[Kelly Bellis]

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.

[Kelly Bellis]

... 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!!