J. Phil Thien's Projects

Quote from: Pelallito on January 05, 2008, 10:38:06 AM
Hi Phil,
I just found your forum and love your design. I hope to make a copy for a 5 gal bucket first and later a larger can. I was left puzzled by this item-2-1/2" couble. I am unfamiliar with the term. Could you expand on that please?
Thanks.
Fred
PS Paypal will go out if I am able to makeit work.

I read your description again and figured it out. I know it as a coupling. A normal application for one is to join two pieces of PVC pipe. I will start getting the parts immediately. I think that I will get that 10 gal can instead of the 5 gal I was originally considering. Thanks again,
Fred

Thanks, I edited that.  It now reads:

"The PVC is a 2" female elbow and a 2" female coupler (for the short outlet or vortex finder tube).  These female components are intended to have a 2" PVC pipe inserted INTO them, so the actual I.D. of the parts is approx. 2-1/2"."

Quote from: D Romano on January 04, 2008, 08:40:56 AM
My question is regarding the small diameter of the baffle. In the trash can separator with shop vac sized inlets, the gap around the perimeter is 1.125". I wonder if Mr. Thien has any advice regarding this gap for a 1200 cfm DC.  The large diameter is about 19" or 20".

Also, I think there was a comment somewhere about using greater than 120 degrees for the large radius. What do you recommend?

Thanks and nice job on this design!

David

The 1.25" was arrived at via testing.  I discovered that making it smaller than 1" increased the # of above-baffle clogs (clumps of debris that wouldn't break-up and wouldn't drop through the slot).  1" seemed to allow everything to break-up and fall through, and I added another 1/8" just to make sure.

For your application, 240-degrees of drop (120-degrees of full baffle) has worked great.

Quote from: Rick Potter on January 04, 2008, 02:00:58 AM
I am trying to figure out the best way to hook up the baffle idea to my 3 HP Powermatic DC.  It has an 8" inlet and a double bag setup.  The mounting hoop where the bags attach has a downward slanting flange about 2" wide which helps keep the dust headed down into the clear plastic bags, and not up to the fabric bags.

My thought is to make a baffle a few inches below this flange and put a plywood top on the hoop instead of the fabric bags.  Each one would have a 6" pipe coming out of the center and out the side of the shop.....no filter bags (California).  If it saves 90% or so, I can vent the really fine stuff outside. 

The Wynn filter site shows a setup somewhat like this, but the baffle would make it even better.

Any ideas??

One more question....Why does one bag on my dual bag setup have about 5 times as much dust in it than the other?  One side has about 3" and the other has about 15" full.

Rick Potter

That will probably work better than you'd think.  The very fines that are exhausted through the wall will dissipate quickly.  The only evidence you'll have is the wooshing noise of the moving air.

On the 2nd question, some (I guess newer) four baggers have an adjustment to control the amount of airflow into each compartment.  I take it your model doesn't offer this?  The reason one bag gets more chips has gotta be that side getting more air.

Hi Monte!

I purchase mine at my local Woodcraft and Rockler stores.  They are called Universal Dust Ports.  They both carry the 2-1/2" fittings, but only Woodcraft carries the 4" version (that won't matter until you're ready for your dust collector version.    ;D

Quote from: windmill on January 02, 2008, 10:55:56 AM
I'm impressed a DC that small actually pulls enough air to work, especially with a trash can separator. I wonder - would it be possible to hook two of them up in parallel? I.e. have two outlets on the trash can? That way, you could run a larger pipe for the intake without losing too much velocity.

It may not be that difficult to change the design. A 6" outlet that splits into two 4" branches ought to do it.

Bas.

I guess it is the design of the impeller for one.  It is an airfoil, which is more efficient than a radial vaned impeller.  Also, it is spinning twice as fast.

And I suppose you could run two of them in tandem.  If I did this I'd be inclined to not only increase the outlet size, but add another input, too.  There would be some (minimal) loss from the splits, and it might be kinda loud.

Some time ago I purchased one of those little Harbor Freight mini portable dust collectors.  I got a helluva deal on it ($70 after stacking some discounts).  It is this one:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94029

It sat unused for a while because I was pretty happy with my Ridgid vac-based cyclone.

HF claims 914-CFM and 9.4" of SP.  We know that the CFM is nonsense, though.  It has a single 4" inlet.  According to BP a 4" pipe can carry about 400-CFM.  My somewhat scientific testing (using two different anemometers) seems to indicate that this unit pulls about 370-CFM.

This unit is only twenty pounds but achieves some pretty impressive specs by using a universal motor spinning a small airfoil type impeller at 6400-RPM (typical DC's use radial impellers spinning at half that speed).

So I decided I'd build a larger cyclone separator and start using it.  I started w/ a 30-gallon can and an MDF top.  Added 4" fittings and my baffle and did some additional testing.  I was happy to discover that adding the cyclone lid only causes an 18% hit to my CFM.  That is pretty spectacular by cyclone standards.

I also had a chance to try connecting the entire assembly to my router table's downdraft box.  I had to do this with a 2.25" reducer to a 2.25" hose, so NOT optimum.  I was stunned to discover that airflow through the tiny (1.5"?) aperture in my router lift was sucking plenty of air.  I had always imagined that real dust collectors would have difficulty moving air through such small holes, but this clearly isn't so, plenty of SP here.

I did limited testing with actual dust because I only have the stock (30-micron) bag filter for the DC at this time.  It was able to separate 98.7% (by weight) of the dust I fed it (mostly fines from machining MDF and hardboard).  It was perhaps a little better but I did have difficulty gathering all the dust from the garbage can when I was done with the test.

I had previously posted that the DC is noisy.  It still is.  Part of that is the noise form the air movement, but certainly part of it is the universal motor, too.  Still impressed with what a $70 machine can do, though.  While this still doesn't provide the 600-800 CFM that some say is needed for fines collection, it is providing over twice the CFM of my current solution and is still compact enough to use, so it will become my new DC until I can make my giant separator lid with 6" outlet and twin 4" inlets, and run 6" PVC to my tools (yeah, right).

Quote from: windmill on December 30, 2007, 10:33:15 PM
I'm using a big trash can (40 gallons). I don't want it to fill up all the way, since it will be too heavy to carry out.

Isn't that what wives are for?   ::)

One common question I get is, "how do you make your circles."  I've just posted a preliminary page with instructions on my Thien Router Table Circle Jig.  This jig was born from a need for lots of large, [preferably] perfect circles.

To make my cyclone tops, I check the diameter of my target garbage can across three different axes (they are never perfectly round).  I average these together and make my top that size.  Then I use a rabbeting bit to cut a relief (notch) so the top sits down into the can about 1/4".  The fact that the cans are always a little less than perfectly round allows the top to "snap" into the can (basically the top brings the can into round).

http://www.jpthien.com/jpthien/cj.htm

Quote from: Twister on December 30, 2007, 06:08:55 PM
Your lid design result is impressive.  I was wondering if you considered, or tried, running your inlet pipe through the baffle plate to dump chips out below the baffle?  This would move the inlet particles away from the outlet port entirely and give you a relatively quiet area between the lid and baffle for the outlet port.

Twister

Yep, here is what happens in that case:  The high velocity of the inlet stirs up the chips in the bottom of the can like mad.  The air from the inlet has to climb over the baffle to exit via the outlet, and in doing so, carries with it chips that have been stirred.

By having both tubes ABOVE the baffle, we give the airstream a chance to "fling" the particles and than make a clean getaway up the output tube.

Quote from: Hobkirk on December 29, 2007, 07:12:11 PM
I thought the IN port outlet was supposed to line up close to the start of the 120 degree extension, but I see that Phil's new design doesn't either.

The elbow should be under the major radius of the baffle to prevent turbulence from picking-up dust from the bin (especially as the bin approaches capacity).  Bas (Windmill) probably could have extended the large radius from 120 to 160-degrees given the size of his fittings.  Perhaps someday when he has time he can experiment and let us know.

Quote from: Hobkirk on December 29, 2007, 07:12:11 PM
You also have a lot more "breathing room" than Phil, which might make it a little easier to construct.

Also reduces SP.  Separators are all about tradeoffs.  More room on top means less room on the bottom (for chips).  But it also reduces the CFM hit.

Nice job.  I hope you'll keep us updated with your observations from continued use!

Quote from: Garasaki on December 28, 2007, 08:30:49 AM
Hi Phil,

(1) basically placed approximately flush with the bottom of the inlet elbow??

(2) Also, have you tested the results of tilting the baffle at all?  Perhaps "downward" with the inlet elbow being the highest point?

(1) Bingo.  Just minimizing the room at the top to maximize room for debris at the bottom.

(2) I've done all sorts of baffle tests, tilted, weird shapes (even using Frisbees of various sizes).  The design I've listed here is a pretty good compromise between pressure loss and separation efficiency.

Quote from: siliconbauhaus on December 11, 2007, 09:29:32 AM
Phil,

I have a small 3hp cman vac. I have the lid form the rockler link attached to a 5gal bucket with a bit of weather stripping on the inside of the lid to try and seal it up.

I don't get any debris in the vac but it does gets full of fines. Overall it sort of does the job but not very well. I empty the bucket and vac when I think about it. I cant say as I notice any difference wether its empty or half full. The filter I use is the one below the hepa as they didnt have any hepa filters when I bought the vac. The filter gets caked with fines and is a pita to clean.

How do I go about getting the info to build one like yours? I'd rather pay you the cash than some company.

I don't have any drawings done yet but there is enough information in the pictures and text here to duplicate my work.

I hope to have some drawings soon (as soon as work lightens up a little).

Quote from: eccentrictinkerer on December 09, 2007, 07:11:05 PM
I saw your original post on bt3central.  I really like your design and am anxious to try it soon. I'm in the middle of a major re-do of my shop so I can't start it immediately.

You mentioned that you have a modded BT3xxx. I'd be interested in your mods. I just got a Wixey digital fence gauge. While testing it I found that the Dark Angel of Shim Death had visited me. I have a Sears 21829 that I thought was immune.

I'm a newbie to the BT3000 and clones, and I'm really impressed with this inexpensive saw. I put a $60 blade in it and impressed my cousin no end.

Well, I'm off to order parts. Thanks for your well thought-out design and forum. I hope to compensate you for your efforts.

J.D.

I saw your shim post at bt3central.  I am surprised you'd have this problem w/ the zip code version of the saw.  But I guess it is the exception that proves the rule?  In any event, replacing shims will allow you to become one with the saw.   ::)

There are some posts of my saw mods at bt3central, you can search my handle.  Basically, they are an extended-length left-side miter slot, a right-side router table, and a support "truss" that holds the entire saw solid as a rock.  I should really write something up for at least the support truss, but here is a link to the appropriate post at bt3central:

http://www.bt3central.com/showthread.php?t=24309

Quote from: knauftj on December 09, 2007, 03:34:57 PM
Phil,

This looks like a great simple design for the small user.  I have a basement workshop and due to space limitations a shop-vac works best for me.  I have a few questions on the details of the baffle as well as the garbage can.  On the baffle what size/type of pvc fitting did you use.  Is it a 2 1/2 inch 90 degree elbow?  On the garbage can I was wondering what the diameter is.  I'm having problems finding steel garbage cans in my area.  I live near you (Madison) and we have mandatory recycling with required plastic garbage cans.  I'm thinking of trying a heavy duty fiber drum since those I can find in all sizes from 1 gallon - 75 gallon.  They also have a steel top that has a locking band included in the construction.  Any thoughts on using a fiber drum?

Regards,

Jon
Madison, WI

The PVC is a 2" female elbow and a 2" female coupler (for the short outlet or vortex finder tube).  These female components are intended to have a 2" PVC pipe inserted INTO them, so the actual I.D. of the parts is approx. 2-1/2".

I just checked my can and it is a Dover Parkersburg 10-gallon can (item #910) that I purchased at my local Ace hardware.  You may find this size is common for people to use with used charcoals.  Maybe check a local Ace?

The diameter of the top is 14-5/8" and it is 17-3/4" tall.

I think the fiber drum would be fine.  Plastic is a no-no as far as I'm concerned because it easily collapses and the static that is created from the circulating air causes problems w/ separation.