Jet DC1100A Thien Conversion to 2 stage system

[Mad Dog]

I, like almost everyone who is reading Phil's blog are trying to find a way to improve our dust collection capabilities without breaking the bank or taking up half our valuable work space.  When I stumbled on Phil's design, I thought for the first time there was an affordable solution that just might work for my small shop.  While my interpretation isn't a break though in dust collection or even unique for that matter, it is a way to utilized off the shelf components and readily available used equipment to create a really good dust collector with great suction that doesn't clog.

I was able to purchase a gently used Jet DC1100A for a reasonable price.  Like most single stage systems, the motor and impeller and fan shroud are reasonably well built and provided a good base to start with.  In order to maximize CFM and SP, I wanted to minimize unnecessary hose length in the system keep the system size to a minimum.  I also felt removing the bulk of the ingested material from direct contact with the fan would be a positive move.  Because the top hat design has shown promise with others, utilizing the single stage collection ring seemed like a good reuse of existing components to achieve similar results.  I have included a somewhat generic 3D drawing of my design.  The basic concept should be convertible to most single stage systems but as always, your mileage may vary.

Installing the Thien baffle in the collection ring as you normally would directs most of the material in to the bin and not the filter.  Speaking of filter, I elected to use the cyclone version which is smaller in diameter, provides more filter area and as you will see, the ability to have a slick clean out box attached.  You'll also notice the lack of cleaning flaps which can compromise the integrity of the filter media.  Compressed air will do just as good if not better and it's reduces the chance of excessive wear. 
The support frame is made of either ¾" MDF or plywood.  Components include a base, 2 sides and a back.  A hole is cut for the inlet to the blower and spacers are added to the back for mounting the motor.  I extended the inlet so it was at the recommended height splitting the intake right at the halfway point which also addressed the inverted cone over-sized hole which has proven to be problematic.  To further reduce back pressure, the outlet from the blower was increased to 6" in diameter immediately after the fan outlet which allowed the use of insulated 6" HVAC ducting I had on hand.  I mounted the system to the wall using a French cleat or you can simply bolt it to the wall.  The filter bracket is constructed the same way only smaller.

The next bit of fun was adding a 3.5 gallon bucket to the bottom of the Wynn filter using a Gamma Lid and some home grown modifications.  A special thank you goes out to Dick Wynn for suggesting this great solution.  The bucket is blue but mostly transparent and the lid screws on to a special ring that is snapped on to the bucket.  The lid itself is has some weather stripping added to the top face and then 4 sheet metal screws hold it to the bottom of the filter.  Using a jig saw, you'll need to cut out the center of the lid so the fines can find their way to the bucket.  It's simple, inexpensive and works perfect.  Once the filter was attached to the mounting bracket, the entire unit was hung from another French cleat.

The collection bin was the final bit to sort out.  I wanted to retain the original bag and to keep things nice and tidy, but it didn't take but 2 seconds to determine my original plan was not going to work.  Undeterred, I attempted a few quick fixes but in the end, a Rubbermaid 32 gal heavy duty trash can was the winner.  I simply made an adaptor ring for the collection ring out of plywood so the trash can mates up and creates a good seal.  I still need to build a support stand for the trash can which is next on the list.

I've also included a 3D drawing of the design in an exploded view.  One note, I did elect to forgo the velocity stack/air port for the intake as purchasing a 10' piece of 6" PVC seemed a bit unnecessary for an 8" long inlet.  Then you have the issue of what to do with the rest of the tubing which for now is a real storage issue and I wasn't planning on any permanent duct runs just yet.  It should also be noted that cyclones don't use a flared inlet so there must be a reason?  Granted the designs are notably different however, the basic premise is the same.  Of course, once I determined the trash can was the best solution, I stumbled across 2' sections of 6"PVC at the local big box store.  Now that I know it exists, I may rethink my design and see if I can add a proper "air port/velocity stack" to my system.

A couple design notes are in order.  First, I needed to position the blower assembly in such a way so I could still reach the on/off switch.  Once I'm comfortable with the overall operation of the system, I'll add a remote switch for convenience.  This will allow me to change the orientation of the system so I have a cleaner route to the filter and better access to the inlet.  Second, I flipped my filter bracket so it was just like the main housing support bracket.  Third, I think I'm going to add a couple guide blocks for the trash can adapter so the mating of three parts is more consistent and less fiddly.

I did a quick, unscientific test with the original configuration just to see how it performed.  I simply hand fed saw dust into the intake and watched as the room filled with dust.  Needless to say, I left the shop in a hurry and waited for the dust to settle.  This was actually worse than when the saw runs normally.  After the conversion, I perform the test this time with a hose attached.  Must to my delight, nothing seemed to escape the system and the amount of fines in the clean out seemed about right.  I need to perform a few more tests in the coming weeks to see how well it's actually working but the CFM and SP seem much improved over the original set up.

[Mad Dog]

As promised, I've included a couple pictures of the nearly finished installation.  While I still have a handful of minor adjustments to make, it is operational in it's current state.  After a dismal showing with the original single stage configuration, the new, improved 2 stage system is impressive for a system with a small by "true" dust collection standards, 1 1/2 hp motor.  I was also able to perform a simple test to see how well the baffle was working.  I grabbed a dust pan full of table saw dust and hand fed it into the inlet.  Using a flashlight, I was able to see the dust swirl around the inside of the ring and then disappear below the baffle.  Clearly a square inlet would help direct the material closer to the sides but it's seemed mostly unnecessary as the dust rarely made more than one revolution in the collection ring and that only occurred when too much dust was added at once.  The other quick check was the filter and the clean out bucket.  While the filter isn't "seasoned" yet, only the smallest of particles found there way in to the bucket and that was after I gave it a quick shot of compressed air.

My list of changes include rotating the collection ring so the inlet is in a different position, move the filter assembly a bit higher on the wall, lower the main unit a bit, add a proper hole for the cord, build a better container raising/lowering system, add a longer length of 5" hose and tidy things up with proper clamps, tape, etc.  While I can't prove it, the insulated outlet to the filter seems to help with the noise level.  However, the overall noise level is very tolerable and much better than the old Shopvac.  I'd also like to add a remote on/off at some point as that would make things a bit easier as well.  Beyond the vacuum itself, my focus will be on adding the necessary duct work to the various tools in the shop that warrant dust collection.

A couple baffle notes.  I used 1/4" hardboard which works perfectly.  I don't see any reason to use anything thicker if you were having any concerns about strength.  I also cut the 1 1/8" slot square at the ends and added a 45 degree downward angle at the entrance edge to ease the transition in to the barrel and an under cut bevel on the opposite side to help direct material down that would otherwise just go around in circles.  In addition, I eased the edge on the underside of the slot slightly.  The intent was to direct the material in to the barrel and minimize the turbulence on the underside of the baffle.  It's a bit of a counter diction in objectives but the changes seem to have accomplished the task at hand.

Before I forget, I'd like to thank Phil for this great idea and taking the time to publish his research on this brilliant solution to an age old problem.  Based on my experience with the mini cyclone (see pictures), I believe I'm getting as good and possibly better separation with the baffle over the mini cyclone.  For a small shop such as mine, this is all the dust collection I need and I couldn't be more pleased with the results.

Bottom line, I saved a ton of money over purchasing a new, full sized cyclone and the performance is easily as good.

[Rudy81]

Outstanding work.  After much research, I have decided to do exactly what you have done with the exception that I will be porting the DC to the outside. 

Do you have any pictures of the details of your build, particularly how you attached the baffle?  I will be purchasing the same Jet DC you have.  I think for a small shop using one machine at a time, the 1.5 HP machine should be sufficient. 

Are you still satisfied with your setup? 

[Rudy81]

In studying your drawings, I wanted to ask about your piece labeled "chimney".  How far does it protrude into the drum?  Is it flush with the drum top, or does it drop into the drum? Would it matter if it was flush or dropped into the drum?

I will also be considering the air straighteners and bellmouth additions others have come up with.

BTW, my thanks to Phil for not only making this design available to us, but for also hosting the forum. 

You have an excellent design and I am grateful you shared your research.

[Mad Dog]

Thanks for the kind words.  Sorry for the late reply but it did give me some time to get a few miles under my belt.

First off, I'm really liking the setup.  It's no 5 hp, 220 volt monster cyclone capable if ingesting 25' tape measures but it is very capable and to my surprise, easier on the ears than my shop vac.  I use it mostly with my 3 hp cabinet saw and it is has tackled everything I've thrown at it so far.  I do need to make a couple modifications to the table saw itself to seal off the area between the table and the base but even with those gaps it does a pretty decent job.

I recently added the dust chute to my old Dewalt 12 1/2" planner and that is where this setup really shines.  Using a 4" hose, it sucked up just about everything.  No more piles of wood shavings all over the floor.  I even made a floor sweep port which is great when you need to clean the floor from other tasks where the collection system would be too cumbersome.  I've seen a very noticeable reduction in fine dust and the air quality is vastly improved.  Since my shop is small, I simply run the hose to where ever I'm making chips/dust.  This keeps the run short and improves the efficiency.

I believe the air straightener/bell-mouth is a perfect addition to this configuration.  Will it make a huge difference in performance?  Most likely not but I do believe it will be noticeable and is something I considered early on but couldn't find the material I needed until after the unit was built.  One ting to note, with a proper bell mouth, it will be a bit more difficult to do the assembly as the diameter of the bell mouth will be larger than the hole in the cone.

The chimney splits the inlet diameter of the ring when assembled.  The other end attaches to the blower inlet.  In other words, it ends right in the middle of the inlet as per Phil's instructions.  The baffle is attached to the cone in the ring via 3 long carriage bolts to keep the underside of the baffle as smooth as possible.  When I drew up the plans, this was an area that I knew I would have to ad lib so it wasn't in the drawings.  I re-purposed some old chrome plated copper faucet tubing as spacers between the baffle and the cone and between the cone and the nut/washer on the inside of the cone.  I figured small and smooth would be a good thing in this space.  The baffle rests just inside the bottom of the ring so it doesn't protrude into the drum.  The Jet has a convenient lip at the bottom.

I know many people choose to vent outside and based on the collection bucket under the filter, you shouldn't see to much material exiting the outlet.  I will say that I'm glad I elected to keep the air inside the shop and recirculate it as it helps keep the hot/cold air out and really helps maintain the temperature.

I hope this all makes sense and good luck with your project.

Mike

[Rudy81]

Mike,

My project also turned out really well.  I do have the air straightener and bellmouth combination.  I needed to install the straightener since I purposefully made the baffle to rotate counter to the DC impeller.

The modest Jet DC is doing a great job with any and all of my tools, although I don't have anything producing more than a standard table saw.

I am venting outside and have not noticed any major problems with the air exchange.  At least not for the short length of time I have been running the machines.

In my case, the DC is also quieter than my Shop Vac which I use for cleanup and to suck up what the top of the TS blade throws into the  blade guard.

[tvman44]

Maddog, does the insulation around the line help lower the noise? :)

[Mad Dog]

Tvman44,

I didn't try a different method of routing the exhaust to the filter but I can say the noise is very tolerable and you don't feel like you have to turn it off as soon as possible.  Like most people, I'm most sensitive to higher pitches and to be honest, the shop vac noise is more that I can take for more than a minute or so,  The DC on the other hand emits a much lower pitch and is much easier on my ears so I generally prefer to use it instead of the shop vac.  I will say it "seems" to be quieter than the original setup but that is a very subjective measurement.

Mike