Dust Extraction Duct Routing - High or Low?

[Mike Kreinhop]

I am in the process of building my basement workshop and have a blank slate for the dust collection system. The dividing wall that separates the shop from the rest of the semi-finished basement is in, but the standard metal door will not be delivered and installed until the middle of August (it's a German thing). The main shop is 5m x 4.75m (16.4 x 15.6 feet) and has a separate closet that is 1m x 2m (3.3 x 6.6 feet), for the dust collection and air compressor. The double doors for the closet have to be cut down to clear the drain pipe obstruction that runs across the ceiling, and will be delivered and installed sometime in late September (yes, more of that German thing). I have plenty of free space to work in and want to install the dust collection ducting and power distribution now. The installation of the cabinets, shelving, and benches, as well as final placement of the equipment will be done later.

I have a 2HP dust collector that I will reconfigure and combine with an Oneida Super Dust Deputy (the metal version) and a pair of Wynn filters. However, I have still not made up my mind about the location of the 120mm metal ducting that will go around three walls of the shop. All of the shop installations I see have the main ducting mounted high, with either rigid down tubes along the wall ending at blast gates near the floor, or blast gates mounted high, with flexible tubing going down the wall to the equipment. Is this done because in most cases the dust collection system was added after the shop was built?

Is there a reason the main ducting could not be mounted low on the wall, with the only rise up the wall at the dust collection equipment? In the two basic scenarios I drew, the horizontal and vertical travel for chips and dust were the same for each piece of equipment. The difference was the cost of material for the ducting, with the high version being more expensive. Does the location of the point where the chips and dust rise make a difference? In my simple way of thinking, the particulate has an opportunity to increase velocity if it is not trying to overcome gravity at the start of the journey to the cyclone.

Given the opportunity to start over, would anyone reconsider the location and routing of the dust collection ducting? I welcome all comments and suggestions, as I don't want to make major changes to the system after it's installed.

To avoid starting another thread, I would appreciate opinions on the air compressor. I don't know what would be a reasonable size for small nail and brad guns. I don't intend on painting or sand blasting in the shop, but want the opportunity to use a few air tools. I have plenty of room in the closet for a compressor, and will have a 16A 400V 3-phase receptacle for it and the dust collector. What is a reasonable size for the compressor and air tank?

[Ole Anderson]

Low on the wall can be in the kick space when standing or moving. High on the wall is out of the way and material travelling up may be in a smaller duct or hose than your final run up if your main run is low. Example, 4" duct to a smaller machine with lower flow will now have to travel up at the end of the main run in, say, a 6" duct where the velocity may not be enough to carry large chips and small off-cuts. That being said, here is my run from the MS and TS, but I am keeping the MS duct at 6" and the TS hose at 5". Only once have I had to remove off-cuts from the upward turned bend.

[Jim Becker]

There's no major dust collection efficiency advantage/disadvantage to either level as long as duct length and bends, etc., are similar. As Ole mentions, there may be practical shop-space/utilization/workflow factors that will make one better than the other.

[John K Jordan]

Mike,

I designed my shop from the ground up and chose to put my ducts high, in fact, I put them in the trusses above the ceiling and brought down 6" pipe to the machines. I did this to get them out of the way. The wall and floor space in my shop is precious and mounting them high got them out of the way and gave me far more flexibility for positioning things. Also, I ran one main line down the middle and branched out to various tools, not possible if mounted low. The system works very well (5hp ClearVue).

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It was a real challenge to snake the ductwork through the trusses without notching a single truss. It would have been a LOT easier to just run them up against the ceiling but that would limit some other things like light placement and high shelves. I ran the HVAC ducts up there too. I'm quite pleased with how it turned out.

As for the air compressor, I opted for a 60 gal 5HP 2-stage compressor. I use nail guns but also air up tractor tires, use impact wrenches, and pneumatic random orbital sanders. The compressor doesn't run as much as it would with a smaller tank. This is more air then you would need for a few air tools but it gives the capacity to do more in the future if things change. The way I look at things like this, the cost of the equipment for more capacity is tiny compared to the total cost of the shop! Adding it now would be a lot simpler and cheaper than upgrading it later.

One thing I did for the air compressor was to run the air through the wall into the main shop so I don't have to go into the closet except to drain the tank. On the wall in the main shop I have an electrical disconnect, gauges, dryers, regulator, and valves. The air lines are plumbed in the walls and ceilings and go to 8 outlets around and outside the shop. I used the 1/2" RapidAir piping and outlet kits.

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JKJ

[Bill Dufour]

If your compressor is hidden in a closet add an automatic drain valve that blows through a hose through the wall to the outside.
Bll

[glenn bradley]

In my shop, wall space (both low and high) is precious. High ducting takes up space in the areas least likely to be used for other things. I have ducts high and low and both work fine. If your ceiling is low there is always the temptation to use tight 90 degree bends at the ceiling/wall or wall/wall junctions. Try to avoid this by using long sweeps or dual 45 degree fittings with a section of straight pipe between. These protrude into the work space more but, a nice looking inefficient duct system is no fun.

[Jim Becker]

John makes mention of something that's very important...routing for efficiency. You ultimately want the minimum duct length and elbows for best performance and running anything around the perimeter is often the direct opposite of that. Hence, the propensity of duct work to be "up high" (or under the floor) so that more direct routing can be facilitated. That's often on a diagonal across the shop for a main trunk, too, depending on where the DC lives permanently in relationship to the tools it will be servicing.

[Carl Kona]

Mike,

I would say efficiency and cost should be cheaper going on the ceiling. I say this on the basis of a main line going straight across the ceiling and wyes breaking off to the equipment as compared to your plan of going around the walls to your equipment. If your DC is in a corner then this main line would go on a diagonal (otherwise down the middle). You don't have a large shop and you are doing the right things with a SDD and larger filter area to keep efficiency up, but you are on the borderline of available CFM using a 2HP DC. Does your DC have a 12" or larger impeller? (that will assure you are starting with enough CFM at your DC). I know going around the room is more tidy but you are adding more 90s and distance between your machines and your DC (which lowers your DC efficiency) Each 90 adds about 9 feet of straight pipe to your already long run of 15 feet per wall times 3 walls plus 2-3 90s is well over 60 feet of pipe just to get to the machine then you add wye's gates, flex, etc.

(check this guide http://www.woodweb.com/knowledge_base/_dust_collection_design_guide.pdf)

The other thing is to get the most efficient setup you will be stacking your blower on top of your SDD which should have your intake close to the ceiling anyways.

On a separate question, does your blower spin the intake air in the same direction as the SDD will spin the intake - when mounted on the SDD? (If not a simple air straightener will help with noise and efficiency).

Hope this helps. Let us know what you do.

Carl

[Mike Kreinhop]

Thanks to everyone for the replies and helpful comments. I decided on a ceiling mounted ducting system after confirming the 120mm pipe will just fit through the corner formed by the ceiling, wall, and sewage pipe that runs across the shop ceiling. I tried a section of DIN110 PVC drain pipe, but the outer diameter is too large to fit in the gap.

I wish I had the ability to run the pipes in joists or run diagonal across the room, but the house was constructed with cast in place reinforced concrete walls and horizontal slabs. My hammer drill gets a workout knocking holes in the walls and floors. Aside from the doors, the only non-concrete structure forming the shop is the GWB wall I had installed last week. The main sewage drain for the house is hidden in a GWB box that allows for the PVC pipe slope as it leaves the building. In one corner of the room, there is another boxed area for the kitchen domestic water and drain. I used two 45-degree elbows to jog around the kitchen obstruction, but I can eliminate them if I don't keep the DC duct flush against that wall.

Here is a rough drawing showing the proposed duct routing. I placed the jointer/planer near the door in case I have to run long pieces through it. All ducting is 120mm, and the blast gates are on the 45-degree splitters. I will use 120mm flexible tubing to go down the wall to the machines. The Minimax saw also has a smaller flexible duct connected to the overhead 120mm metal duct, through a reducer, above the blade guard.

The ceiling obstructions are shown in very light dashed lines. The largest is the main sewage line that enters the basement near the main door and exits the house at the top of the drawing. The other obstruction for the kitchen is in the lower right corner.

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Please feel free to critique the layout, but also understand I am limited to the space available.

Here (http://www.holzkraft-maschinen.de/produkte/holzkraft/zubehoer/absaugen/index.html) is a link to the Holzkraft page for the DC ducting I will be using.

[Mike Kreinhop]

The other thing is to get the most efficient setup you will be stacking your blower on top of your SDD which should have your intake close to the ceiling anyways.

On a separate question, does your blower spin the intake air in the same direction as the SDD will spin the intake - when mounted on the SDD? (If not a simple air straightener will help with noise and efficiency).

Thanks, Carl. I will be mounting the blower over the SDD, and it does spin in the same direction as the airflow in the SSD. I measured the impeller as soon as it arrived, but I can't remember the diameter, but remember it was over 12 inches in diameter.

[Jim Becker]

Good start on the design. Please consider extending the trunk from the saw down to the J/P and a small drop to the DP from there. The J/P is probably the most demanding tool in the shop relative to volume and that long perimeter run is going to kill performance.

[Alan Lightstone]

Good start on the design. Please consider extending the trunk from the saw down to the J/P and a small drop to the DP from there. The J/P is probably the most demanding tool in the shop relative to volume and that long perimeter run is going to kill performance.
+1.

No matter how I modified it, I can't get good dust collection from my Laguna J/P even with a 5HP Oneida, so I'd work hard on maximizing the flow from that.

[Alan Schaffter]

Thanks, Carl. I will be mounting the blower over the SDD, and it does spin in the same direction as the airflow in the SSD. I measured the impeller as soon as it arrived, but I can't remember the diameter, but remember it was over 12 inches in diameter.

Why is the ducting around the perimeter of the shop? That is the longest route and longest run requires 3 90° bends. As you know you should avoid 90's at all costs. A hypotenuse is much shorter than the sum of the sides. With only a two hp DC you need the most efficient layout possible (shortest runs, fewest bends). A 2 hp unit is not suited for a fixed, ducted setup. If you can, depending on the plumbing obstructions, consider these layouts - shorter individual runs and no 90° bends. It will require more duct, but the run from every tool to the DC will be shorter than your design.

http://www.ncwoodworker.net/pp/data/500/medium/Shop-1-Model-A.jpg

http://www.ncwoodworker.net/pp/data/500/medium/Shop-1-Model-B.jpg

[andy bessette]

I see 2 options:

A main duct running diagonally from the DC to approximately the DP

or

A main duct running first to the main saw port, then turning down the centerline to the JP.

Other branches run at 45* from that.

[Mike Kreinhop]

Thanks again for the comments! I attached more images of the workshop. The hideous wallpaper will be painted white this weekend. :)

I can't make any diagonal runs across the ceiling because of the obstructions and the surface mounted lighting fixtures. I currently have two large fluorescent dual-tube fixtures, but will be replacing them with four smaller fixtures that are better suited for a workshop. I will take Jim's advice and will extend the overhead run for the saw to the J/P.

The first image shows the drain pipe obstruction and its relationship to the DC closet and rest of the shop. In my original drawing, the obstructions are shown with light gray dashed lines.

https://farm5.staticflickr.com/4312/36042368096_fa3a5fcf77_c.jpg


The next image shows the interior of the drain pipe box and the only path available to feed the 120mm duct. The duct just fits between the drain pipe and the corner formed by the ceiling and the wall.

https://farm5.staticflickr.com/4327/35692873710_012f5c06d5_c.jpg


The last image shows the rest of the shop, with the equipment (minus the SC2 saw) stacked in the corner. The kitchen plumbing obstruction is shown in the upper right corner. The black plastic shelves holding the HOB260NL parts are temporary and will not be used in the shop.

https://farm5.staticflickr.com/4291/35242218234_b8a9bcb49d_c.jpg

I haven't installed the electrical distribution yet, but will wait until after the walls and ceiling are painted and dry. Not shown in this image is the 32A three-phase distribution panel on the right side near the main door. We are fortunate in Germany to have three-phase service in residential buildings. The bandsaw, drill press, and J/P are single-phase, but I have the motor, contactor, and replacement components from Holzmann to convert the J/P to three-phase.

[Jim Andrew]

Regards to your question about air compressor, I purchased the smallest oil lubricated air compressor I could find, and it works fine for me. One cylinder, big enough to run staplers and brad nailers, even a framing nailer, but you might have to wait for it to catch up after shooting several nails, even works with my tire machine, although breaking beads makes it run constantly.

[andy bessette]

...you might have to wait for it to catch up after shooting several nails...

For me that would be an unacceptable deficiency.

[Ted Reischl]

I have had DC up and down. I learned my lesson.

The lesson is: If you can run low to machines that will make splinters (like a narrow piece that gets sucked into the TS) do so. Those splinters will get hung up eventually and fixing things up on the ceiling is not fun. If it is just dust, like off a sander, high works fine. If you use larger forstner bits, those chips are NOTORIOUS for clogging things up.

The other thing I learned is to NOT run grounding wire inside the ductwork. Bad. Just plain bad. What was I thinking? Oh, I remember now, I was new to woodworking and some "expert" told me that worked really well.

[Mike Kreinhop]

I'm still chugging along with my shop build. So far, the walls have been painted, the electrical panel installed, and the electrical raceway is almost finished. Once I install the receptacles, I'll add the wiring and terminate both ends. The top row of breakers are four 3-phase C16 breakers. The bottom row are a mix of C16 and B16 single-phase breakers.

https://farm5.staticflickr.com/4302/35438126764_61c9ce5832_c.jpg

For now, the equipment is stacked in the middle of the room while I install the electrical and ducting. The Minimax SC2 Classic is still mostly disassembled in the middle of the room. I had to remove the cast iron top and concrete counterbalance from the saw chassis in order for us to maneuver the saw down the stairs. The concrete counterbalance was the heaviest item to move (it's under the hand tools in the photo below).

https://farm5.staticflickr.com/4313/36137212651_bd7219d353_c.jpg

The 120mm ducting will be ordered tomorrow and should be delivered next week. I changed my mind on the DC blower, and will be using a Bernardo RV 350 blower (http://www.bernardo.at/shop/en/wood/wood-working/dust-collectors/radial-collectors/rv-350.html) instead of the salvaged blower from my Bernardo DC 350. The RV 350 has a larger impeller and a 3HP motor. I'm driving to a Bernardo distributor in Polch tomorrow (near Koblenz) to exchange my DC 350 for the RV 350. The RV 350 inlet is 150mm (5.9 inches), which is a better fit for the 6-inch outlet of the steel Oneida Super Dust Deputy.

[Alan Schaffter]

I'm still chugging along with my shop build. . . . I'm driving to a Bernardo distributor in Polch tomorrow (near Koblenz) . . . .

Until this post I didn't catch on that you were in Germany. I'm headed that way in two weeks for a two week tour that starts in Frankfurt, heads south- Heidelberg, Black Forrest, Schwangau- then loops back up- Oberammergau, Munich, Rothenburg, Dresden- and ends in Berlin.

It is really too bad you have that big beam in the way. Unless you drop the duct down everywhere which gets you under the lights too or just where the beam is located which may not be possible either, it is pretty hard to run diagonal ducts in your shop. That is much better than running the duct around the perimeter, but you can only do what you can do. One thing you can do to lower the height of a cyclone, is to configure it as a push-through- I've been doing that for almost 20 years. In addition to lowering the overall height, another advantage is you don't need an airtight dust drum- an ordinary plastic trash bag will do. I've got the height though I have a long cone (3D) cyclone.

http://www.ncwoodworker.net/pp/data/1329/medium/P10100382.JPG

http://www.ncwoodworker.net/pp/data/1329/medium/P10100401.JPG

http://www.ncwoodworker.net/pp/data/1329/medium/P10100531.JPG

[Mike Kreinhop]

Until this post I didn't catch on that you were in Germany. I'm headed that way in two weeks for a two week tour that starts in Frankfurt, heads south- Heidelberg, Black Forrest, Schwangau- then loops back up- Oberammergau, Munich, Rothenburg, Dresden- and ends in Berlin.

When you leave Frankfurt for Heidelberg, you'll pass within a few kilometers of my house. You are hitting great spots on your tour! Some of my friends come to Germany from time to time, and I take them to some of the places you'll visit. They will usually visit for a week and want to see everything, but don't appreciate the distances, driving time, and occasional stau (traffic jam) that could take hours to clear. You have an ambitious schedule for two weeks. :p


It is really too bad you have that big beam in the way. Unless you drop the duct down everywhere which gets you under the lights too or just where the beam is located which may not be possible either, it is pretty hard to run diagonal ducts in your shop. That is much better than running the duct around the perimeter, but you can only do what you can do. One thing you can do to lower the height of a cyclone, is to configure it as a push-through- I've been doing that for almost 20 years. In addition to lowering the overall height, another advantage is you don't need an airtight dust drum- an ordinary plastic trash bag will do. I've got the height though I have a long cone (3D) cyclone.

Unfortunately, I have to work in the space available. I picked up my new blower this afternoon, and I think it will work fine. The input to the blower just fits into the top of the cyclone, so a little gasketing and some metallic ducting tape should ensure an airtight seal.

[Alan Schaffter]

When you leave Frankfurt for Heidelberg, you'll pass within a few kilometers of my house. You are hitting great spots on your tour! Some of my friends come to Germany from time to time, and I take them to some of the places you'll visit. They will usually visit for a week and want to see everything, but don't appreciate the distances, driving time, and occasional stau (traffic jam) that could take hours to clear. You have an ambitious schedule for two weeks. :p

We are actually traveling with Tauck (http://www.tauck.com/tours/europe-tours/central-and-eastern-europe-tours/germany-tour-ga-2017.aspx?tabPage=Itinerary), a US tour company. This is our 8th trip with them. We really don't spend much time in Frankfurt, so we are going a day early and have arranged a walking tour. From there we head to St. Goarshausen and travel by boat to Rüdesheim before heading back to Frankfurt. The next day we go to Heidelberg before heading to Hotel Traube Tonbach in the Black Forest. Unfortunately we have already seen some of the sights on the southern portion of the trip (Oberammergau, Linderhof, Munich) when we did Tauck's Alps & Dolomites tour a few years ago.

[Mike Kreinhop]

It's time to update this thread. Between work and frequent travels out of the country, I finished the electrical distribution, dust collection ducting, and the dust collection blower assembly. The only remaining tasks are to build the blower output box for the Wynn 35 series filters, install the differential pressure gauge for the filters, install the exhaust port in the DC closet, and tie up a few loose ends. Then I can finish assembling my shop equipment, have the Minimax saw commissioned, and start building cabinets and shelves.

Here is a picture of the blower assembly. It's in a 1 x 2 meter closet and will also contain the air compressor, which is still in my garage. I installed the German equivalent of Unistrut to the wall and attached everything to the channel. This allows me to make one permanent connection to the house and still have the ability to change hardware later. I still need to attach the bungee cords to the 35-gallon dust bin, but the suction holds it on well enough that I can pick it up when I lift the plywood cover.

https://farm5.staticflickr.com/4432/37240928086_ea586bd4c8_b.jpg (https://flic.kr/p/YJRut1)
DC_System-1 (https://flic.kr/p/YJRut1) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


Here is a closeup of the mounting. The rubber isolation mounts have a good shear rating, but work best in compression. I used four to hold the main blower panel and one to counter the torque caused by the top heavy assembly. They effectively eliminate the vibration and nothing is felt from the dining room above the shop.

https://farm5.staticflickr.com/4393/37430450265_e8f4091303_c.jpg (https://flic.kr/p/Z2AQNM)
Blower_Motor (https://flic.kr/p/Z2AQNM) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


Here is the first string of 120mm ducting along the south wall. The first port on the left is for the Minimax SC2.

https://farm5.staticflickr.com/4372/37287769251_e7be2dcc26_c.jpg (https://flic.kr/p/YNZyHi)
Ducting-5 (https://flic.kr/p/YNZyHi) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


More of the ducting showing the ports for the sanders, drill press, and sliding compound miter saw. The Minimax SC2 is still in pieces, but I hope to have most of it assembled next weekend. Maybe.

The extra hardware dangling from the blast gates are the 120mm to 100mm reducers and the compression clamps. The SC2 blade guard also has a dust port, and there is an 80mm blast gate and coupler for it in the upper left corner of the picture.

https://farm5.staticflickr.com/4443/36618306143_0fa4ec31e1_c.jpg (https://flic.kr/p/XMQoDV)
Ducting-4 (https://flic.kr/p/XMQoDV) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


The last bit of ducting. These two drops are for the bandsaw and the jointer/planer.

https://farm5.staticflickr.com/4470/37240927756_208a7e4a8d_c.jpg (https://flic.kr/p/YJRunj)
Ducting-3 (https://flic.kr/p/YJRunj) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr

[John K Jordan]

Nice looking installation! I really like your isolation solution.

I've never seen that type of electrical channel you have around the room. Is that commonly used where you live? Seems like it would make changes a lot easier!

Installing a good cyclone DC was one of the two best things I did when I built my shop. The other was heat and air!

JKJ

[andy bessette]

Very neatly done.

[Mike Kreinhop]

Nice looking installation! I really like your isolation solution.

I've never seen that type of electrical channel you have around the room. Is that commonly used where you live? Seems like it would make changes a lot easier!

Installing a good cyclone DC was one of the two best things I did when I built my shop. The other was heat and air!

JKJ

The isolation is required. The walls and floors for my house were cast in place reinforced concrete, so direct vibration travels well through the structure. When I was using the hammer drill for the anchors, my wife could hear and feel the impacts no matter where she was in the house.

The plastic channel is common for industrial settings and offices. Most of the construction here is masonry and it's easier to run the electrical and communications infrastructure in the channel than try to carve a path through brick or concrete.

I think fresh air will be my next major project after the shop is set up. As a below-grade basement, the temperature stays a comfortable constant year round.


Very neatly done.

Thank you!

[Bill Adamsen]

If mounting high and expecting a number of gated drops on the run, try to mount the "Y"s so the drops comes off the side. That reduces the amount of dust that will drop into a closed drop. Typically it requires mounting the run some distance from the wall which may not be practical in your setup.

[Mike Kreinhop]

Update for 2 October 2017.

The dust collection system is nearly complete, with just a few bells and whistles to add. I still have to install the filter efficiency meter and pitot tube, the chip level detector, and the DC closet door vent. However, the system is fully operational and is much quieter than I thought it would be. I was going to line the DC closet interior surfaces with sound absorbing foam, but will hold off for now.

Here is an image of the DC closet showing the newly installed filter box and filters. I'm using a pair of Wynn 35BA222NANO filters, each with an 18FP30 filter pan to make cleaning easier.

https://farm5.staticflickr.com/4509/23608697328_f262e5ac97_c.jpg (https://flic.kr/p/BYdKcE)
DC_System-2 (https://flic.kr/p/BYdKcE) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr

The filter box is made of 12mm plywood glued and nailed to a 44x44mm frame. The front face of the box is attached using screws so I can access the interior when needed. A dual 9mm neoprene gasket is between the box and the front face. I had to suspend the box from the ceiling using threaded rod so the side would be at the same height as the blower assembly output port.

My air compressor will fit nicely under the filters, and the 3-phase receptacle is behind the filter on the right.

Here is a closeup of the connection from the blower assembly to the filter box. I used a section of 180mm flexible duct that I formed into a rectangle slightly larger than the output port of the blower assembly. A simple wooden frame on each end of the flexible duct makes the connection secure and airtight.

https://farm5.staticflickr.com/4489/37429317852_d7294bba31_c.jpg (https://flic.kr/p/Z2v3bq)
DC_System-3 (https://flic.kr/p/Z2v3bq) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr

[Alan Lightstone]

Beautiful installation. I'm jealous. I'm never going to get mine to look that neat.

[Jim Finn]

I installed 6" duct from all my equipment to my 2HP dust collector. I ran the duct along the wall on the floor. IT worked well and because the duct did not go all the way up to the ceiling and then back down to the equipment I had a shorter duct overall. I decided to move my dust collector to a separate building and this added about 20 feet of 6" metal duct. I saw no difference in the airflow when I made the change. So my conclusion/opinion is that if you run large enough duct (6") the length of duct does not make a whole lot of difference. If I were to make a new duct system in a new shop I would still run the duct along the wall on the floor again.

[Carl Kona]

Mike,

What a phenomenal installation! It looks more like a off the shelf production setup than a homemade 1 off system. I appreciate you sharing your build.

I am in the process of doing something similar (but not quite the same caliber). Two areas I was interested in was your rectangle hose transition from blower to filter box and how your trash can lid is attached to the can. Specifically how you squared up the hose without damaging it and how you attached/sealed the hose to your connecting blocks.

Thanks in advance for anything you can share.

Carl

[Mike Kreinhop]

Thanks, Alan and Carl,

Here are two interior images showing the mounting of the interface duct and the filter efficiency probe. I used M6 bolts and captive nuts inside the filter box so I could remove the duct without opening the box. The damaged areas along the opening were caused by the drill I used to make the pilot holes for the jigsaw. I should have used a scrap peice of wood as a backing, like I did when I drilled the holse for the captive nuts.

https://farm5.staticflickr.com/4499/36827108454_aa923a2710_c.jpg


https://farm5.staticflickr.com/4511/37505699692_81d48dfb5d_c.jpg

The opening of the blower assembly was about 155mm X 115mm, which gives a perimeter of 540mm. The closest available flexible ducting with the same or larger perimeter is 180mm duct. The external diameter of the 180mm duct was 185mm, so this gives a perimeter of 581mm.

The aspect ratio of the height to width of the blower assembly is 0.742, so the dimensions of the modified duct are about 166mm X 123mm. To make the numbers work, I used 166mm X 124mm for the final duct size.

I then took a half meter section of the 180mm duct, compressed it, and held it in a compressed state with large nylon ties. This gave me a rigid tube to work with while I marked the length for the points to bend. I created a reference line along the length of the tube using a Sharpie marker and a carpenter’s square.

The reference line was the starting point for the fabric tape measure I wrapped around the tube. I made a series of marks on one end of the tube at the 166mm, 290mm, and 456mm points along the tape measure. I made the same marks on the other end of the tube, then connected the marks using the Sharpie and carpenter’s square.

Now that I had the bend lines marked along the length of the tube, I cut the nylon ties in order to make forming the rectangle easier. I clamped a long strip of scrap 22mm plywood in a shop vise and fed one end of the 180mm tubing onto it. After aligning a bend line along one corner of the plywood strip, I began pressing the wire of the flexible tubing onto the corner to start the bend. I follwed the line along the tubing until I had to remove it and start from the other end. The plywood was not long enough to accommodate the entire length of tubing, and I didn’t want to make it so long that it would break under the pressure of forming the bend.

I repeated this process for the four bend lines until I had the start of a rectangle with rounded sides. Once the bends were started on the plywood form, it was easy to continue the bend without the form to 90 degrees and a reasonable small radius. While I finished one corner and moved to the next corner, I also straightened the curved side as best as I could to form a decent rectangle. This process took me about 30 minutes to square the sides of the 180mm tubing.

The wooden frame to hold the tubing was easy. I used four pieces of scrap wood for each end and glued them together so the tubing was a friction fit ready for silicone sealant and straps to hold it in place. You can see in the image above that the strap is held in place with a 4x12mm screw and washer. The strap was off the shelf at the local hardware store; although, I did have to trim about 10mm from one end of each strap for the short side of the tubing.

Before screwing the straps in place, I ran a bead of silicon sealant along the inside of the wooden frame, slid (pushed and tugged) the tubing in place, and then snugged the screws down. I have a nice right angle attachment for my drill that made it easy to insert the screws. I filled in the corners between the frame and radius of the tubing with more silicone before letting it cure overnight.

Here are two images of the interior of the box showing how the Wynn filters are attached. I bought the angle brackets from the hardware store, attached them to the box with screws and nuts, then used the Wynn clips to attach the filters.

https://farm5.staticflickr.com/4495/36827108894_92e749b77e_c.jpg


https://farm5.staticflickr.com/4488/37536909841_2fdbb207c0_c.jpg


I have not detected any leaks yet from the box, but if I do, I will run a bead of silicone sealant along the seams where the frame and plywood meet.

I do not have any images of the trash can lid, but I used a piece of 24mm plywood cut larger than the trash can top, a router, and a homemade circle jig for the router to cut a groove in one side of the lid that mates with the trash can top. I had to make several passes for depth and diameter to allow the 27mm gasket (3x9mm strips) to fit in the groove. The gasket section is wider than the trashcan top, so there is a little wiggle room available when putting the lid on the can. I now have a bungee cord to keep the lid snug to the can and to hold the lid to the cyclone filter base when I remove the can to empty the contents.

[Carl Kona]

Thanks Mike for the response. In addition to the detailed explanation, I also realized that you used the internal Wynn filter clips which I also like.

Thanks again,

Carl

[Mike Kreinhop]

Rather than create a new thread, I decided to continue with this thread.

This weekend I installed digital ammeters in my shop power 3-phase distribution panel. One ammeter is a 3-phase unit that displays only current and scrolls through each phase automatically. I have this connected to the main input feeder so it measures the total shop current. The other ammeters are single-phase and display both voltage and current. I have these connected to the circuit breaker for my DC system. My intent was to baseline my DC system and measure the airflow at each blast gate using the Dwyer 477AV-2 and 166-6 pitot tube. However, my initial power measurements are confusing (to me).

Here is an image of the ammeters with the DC system off and only the lights to the shop drawing current (on phase L3). In case it isn't clear, for the single-phase ammeters, the number on the top is the voltage and the number on the bottom is the current in Amperes.

https://farm1.staticflickr.com/918/42528033435_dbba33f135_c.jpg
(https://flic.kr/p/27N4hFM)DC_Off (https://flic.kr/p/27N4hFM) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


I closed all of the blast gates and turned the DC system on. Here is an image of the ammeters with the DC system running, but no airflow through the system. The average current for each phase is about 3.2 Amps.

https://farm2.staticflickr.com/1806/43384473822_8f37e0915e_c.jpg
(https://flic.kr/p/296JLzm)DC_Gates_Closed (https://flic.kr/p/296JLzm) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr

I opened all of the blast gates and turned the DC system on. Here is an image of the ammeters with the DC system running with maximum airflow. The average current for each phase is about 3.2 Amps.

https://farm2.staticflickr.com/1762/42528033815_c4e6bebbf5_c.jpg
(https://flic.kr/p/27N4hNk)DC_Gates_Open (https://flic.kr/p/27N4hNk) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr


The difference in the current draw for the DC system with the blast gates open and closed is effectively nothing. I verified that there were no leaks in the system, and with the blast gates closed, I couldn't detect any air flow from the filters.

I then disconnected the input to the Oneida SDD to see if my 120mm ducting was choking the system even with the gates open. The readings were the same. I put a board over the SDD input to block it off, and the readings didn't change.

I expected a big difference between the two readings and am not able to explain this. Any suggestions are appreciated.

[andy bessette]

That's a deluxe setup.

[David L Morse]

Mike, when you made the electrical connections to the blower motor did you verify that it was rotating in the right direction? While I have no actual experience with reverse fan rotation in a pressure blower it does seem like that could cause what you are observing.

[Mike Kreinhop]

That's a deluxe setup.

Thanks, Andy! I bought the 3-phase meter from Mouser Electronics and the three single-phase meters from an eBay vendor in China. All of the meters came with current transformers; although all required some additional work to make them fit in my distribution panel.


Mike, when you made the electrical connections to the blower motor did you verify that it was rotating in the right direction? While I have no actual experience with reverse fan rotation in a pressure blower it does seem like that could cause what you are observing.

The DC system works well, I think, but there aren't any other systems near me with which to compare it. To remove my nagging doubt, I did reverse L1 and L2 on the blower assembly plug to reverse the motor direction while I had the ducting disconnected from the SDD. Most of the 3-phase cable plugs here have a nice feature that allows the user to rotate the L1 and L2 pins or sockets with a small screwdriver to change the phase rotation. After reversing the rotation, the blower was much noisier, the meter readings were the same, and there was no suction at the SDD inlet. I'm confident I had it turning in the correct direction.

I made a few quick measurements with the Dwyer 477 and 166-6 along the 3-meter length of ducting that connects to my jointer/planer with only that blast gate open. I started in the center (radius) of the duct and moved towards the edge in 1cm increments. The average velocity was 3,250 ft/min. Without any factoring for turbulence, this is about 396 cubic feet per minute. I have a 2-meter section of 110mm S&D pipe that I was going to use to test at each blast gate, but I think I will find a section of 160mm S&D pipe instead.

[Jim Becker]

Darn...it looks like you have the Starship Enterprise's control setup there!

[Mike Kreinhop]

Darn...it looks like you have the Starship Enterprise's control setup there!

Thank you! I was inspired by others here.

[Jim Dwight]

You do not need a big compressor to drive pneumatic nailers. My favorite is a 25 lb Senco that is rated maybe 1/2 hp, has a 1 gallon tank. https://www.amazon.com/Senco-PC1010-1-Horsepower-1-Gallon-Compressor/dp/B0000AQK78/ref=sr_1_1?ie=UTF8&qid=1531872168&sr=8-1&keywords=senco+compressor I've used it with my flooring nailer and framing nailer but with those, I have to nail fairly slowly but for small jobs, it is not a problem worth solving by dragging in my bigger compressor. For nailers up through 15 gauge, I can nail as fast as I want. It's also pretty quiet but if you are putting it in a closet, that doesn't matter. Anything this size or bigger will work for nailers.

[Mike Kreinhop]

You do not need a big compressor to drive pneumatic nailers. My favorite is a 25 lb Senco that is rated maybe 1/2 hp, has a 1 gallon tank. https://www.amazon.com/Senco-PC1010-1-Horsepower-1-Gallon-Compressor/dp/B0000AQK78/ref=sr_1_1?ie=UTF8&qid=1531872168&sr=8-1&keywords=senco+compressor I've used it with my flooring nailer and framing nailer but with those, I have to nail fairly slowly but for small jobs, it is not a problem worth solving by dragging in my bigger compressor. For nailers up through 15 gauge, I can nail as fast as I want. It's also pretty quiet but if you are putting it in a closet, that doesn't matter. Anything this size or bigger will work for nailers.

The compressor I bought was about the same price delivered as the Senco you linked from Amazon. It was on sale and has a 3HP 3-phase motor. It's not the quietest compressor on the block, but the noise is manageable when the closet door is closed and it can't be heard or felt upstairs. It's also light enough that my wife and I can carry it up the stairs when it's time to take it outside and purge the sprinkler system in the winter.

https://farm1.staticflickr.com/798/26411035577_8ea4d5be74_c.jpg
(https://flic.kr/p/GeRsJn)DC-System-4 (https://flic.kr/p/GeRsJn) by Mike66GE (https://www.flickr.com/photos/42211292@N04/), on Flickr

[Art Mann]

I used a duct system at floor level on my last shop and it worked far better than an overhead system because of the reduction in flex hose length and the straighter galvanized pipe runs. I am using a different collector this time around and I am trying to decide the same thing as you. Some energy (and ultimately cfm) will be lost in lifting dust to a height higher than the cyclone due to the principle of conservation of energy but I don't know how much.