Thread: Filter or cyclone?

Thought I would document by extractor rebuild here in case anyone else can benefit from it. I'm following a lot of the construction done by Jonno in this thread so you'll notice quite a few similarities.

Firstly, after removing the motor from the base, I built a simple frame. This will be the start of the surrounding box, but for now it's just to hold the motor up at the right height. The motor is pretty heavy so I'll probably end up fixing this frame to a wall.

It's not terribly pretty, but it's stable and does the job. Eventually I might get a piece of extruded aluminium or something similar to mount to the dusty wheel base and to the motor. But this'll have to do for the moment.

Here is the frame with motor/impeller lying on its side.

photo 1.jpg



Removed the black plastic outlet from the impeller and made a small frame which fits in its place. The inside of this frame is flush with the inside of the outlet allowing for the maximum amount of airflow.

photo 3.jpg



Another smaller frame is then made to go perpendicular to this one. It sits flush to the outside. I used 12mm ply for this additional frame as we'll need to put another piece inside it later on. Here is how they are meant to align.

photo 4.jpg



Whilst the two frame pieces were drying, I took the intake piece off the front of the impeller. Jigsawed out a circle the same size and used the original front piece to mark out and drill the screw holes.

photo 2.JPG


Still to do:

• Sand the pieces flush so there are minimal air gaps
• Get a 6" pipe and cut out the hole for the intake
• Get some longer screws to attach the new intake circle onto the front of the impeller
• Make the curved piece that mates the impeller outlet to the bag section

In order to reduce air leaks, I'm thinking of making a visit to Clark Rubber to buy some rubber to place between all the mating parts. Do people think this would be worth doing?

Cheers,
Af.

Originally Posted by Afro Boy

In order to reduce air leaks, I'm thinking of making a visit to Clark Rubber to buy some rubber to place between all the mating parts. Do people think this would be worth doing?

yep, I used a rubber gasket and slobbered silicone all over it on both sides.

Picked up some rubber strip, screws, and odds and ends to finish this part of the job. Started giving some thought to the ducting as well.

• 6" (150mm) ducting throughout for as much as possible
• 2 x 45º bends at the corners
• Branch with a 4" outlet to go to the top of the table saw (6" to the body)
• 6" - 4" reducer for the jointer/thicknesser combo (not yet prepared to cut into that shroud!)
• Total length of ducting is around 7 - 8 metres

Here's a really terrible drawing:

photo.jpg

Anything that I'm particularly doing wrong here?

Cheers
Af.

This is not quite a direct answer to the question but it may be helpful in a small way.

My home garage workshop has seen an evolution in my dust management strategy that started with a shop vac, then to a dust collector which was subsequently added to with a pleated filter, then an extra couple of shop vacs added for specific purposes (eg one just for the drill press - very good!) then cyclones on those shop vacs, then a second simple drum stage to the dust collector to collect chips from the thicknesser. Somewhere along the way, I added a whopping big industrial wall fan to blast dust out of the garage door that was being generated by my SCMS. Likewise, three domestic wall fans at key locations keep dust out of my face when using my router table, drill press and SCMS.But, the most impressively performing thing that I have added was pretty well the last in this succession of upgrades and that was an overhead dust filtration unit.


Air filtration Unit-1.jpg


Even if I am just doing metal work in the garage now, I turn it on, knowing that although I vacuum loose dust regularly in the workshop, just walking around stirs up any residual dust.

What makes me so impressed about the dust filtration unit is the difference that I now see in the afternoon rays of light passing in from a western window. Before adding the overhead dust filter, dust was always to be seen in those rays of sunshine. However, when the filtration unit has been running a while, I see none. Highly recommended!


Of course, I now get a bit cocky with it insofar as I found a new way of removing dust from the workshop last week. I just opened both garage doors, turned on all of the outwardly facing fans and blasted away with a small electric leaf blower, blowing all surface dust out of the garage doors. That sure cleaned out the dust under benches and in all sorts of hiding places as well as making the floor look very clean. On the downside, it created a whole fog of airborne dust inside the garage but I just turned on the air filtration at full speed on the longest timer setting and withdrew to let it run overnight. Next morning all of the obvious airborne dust had gone and the whole shop was looking a whole lot cleaner. Yup! - I know that the idea of stirring up all of that settled dust will scare most sensible people but it is done very quickly with a leaf blower so that personal exposure is minimised, time-wise. Better done in rainy weather, also, so that the dust is settled when it is blown out of the garage doors and then hosed off the driveway the next day.Anyway, I just thought that it might be valuable to insert my observations about how effective an overhead dust filtration unit is at removing airborne dust. In hindsight, it should have been a much earlier addition to my dust management strategy before the cyclones, albeit they are terrific for what they do.

Originally Posted by Charleville

This is not quite a direct answer to the question but it may be helpful in a small way.My home garage workshop has seen an evolution in my dust management strategy that started with a shop vac, then to a dust collector which was subsequently added to with a pleated filter, then an extra couple of shop vacs added for specific purposes (eg one just for the drill press - very good!) then cyclones on those shop vacs, then a second simple drum stage to the dust collector to collect chips from the thicknesser. Somewhere along the way, I added a whopping big industrial wall fan to blast dust out of the garage door that was being generated by my SCMS. Likewise, three domestic wall fans at key locations keep dust out of my face when using my router table, drill press and SCMS. .

I can see a number obvious causes for your dust dust problems that you may want to think about.

1) The use of vacuum cleaners (VCs) is a major source of dust - many VCs generate more fine dust than they pick up so the first thing I would do is stop using them or locate them outside the shed and install some ducting points inside the shed. I consider VCs as dust devils if used inside a workshop. If you attend to the next 3 items you will find the need to even use a VC will drop dramatically.

2) You haven't said what size dust extractor you were using, but if it is not big enough it will simply not capture dust at source.
What size ducting are you running? If it even part of it is only 4"or smaller then that limits the flow to around 40% of what is needed to capture fine dust. At least 6" ducting is needed but it's no good upgrading to bigger ducting unless the machine ports are opened up to suit the ducting size and additional air paths are added so that air can get into machines.

3) You haven't said where your DC is located but if it's inside your shed that means more fine dust inside the shed. This is a major contributor to shed dust. If you can't locate it outside then putting it into an enclosure inside the shed and venting outside is an alternative.

4) The next thing is adding chip collectors to dust extractors will immediately slow down the flow rates. This means your DC cannot capture as much fine dust at source as possible.

5) The use of industrial fans or blowers does very little for the movement of very fine due from a shed. While it may look like dust is being removed from a shed that will be the visible dust but much of the fine dust just gets stirred from surface by these fans and makes things worse.

Standard woodworking room air filters only catch about 70% of the fine dust in the air during a single pass, and as they have low air speed they do not reach very far into a shed. This means they need many many passes of air to clean up something like a shed. This is demonstrated by the fact that it takes all night for the room air filter to clean the shed air. More significantly, most room air filters simply cannot keep up with capturing the large amount of very fine dust generated by processes like thicknessing or sanding large pieces of wood. This means you are working in a fog of fine dust. The most dust generation I have measured that standard wood working room air filters can keep up with is turning small items AND where the room air filter is located within 50 cm of the work.

So instead of buying a room air filter it would be better to tackle the above problems.

I have tested of several room air filters including the lab grade room air filter that I have in my shed. That filter that has a 25% greater flow rate than the standard woodwork room air filters and catches more than 99.97% of the fine dust in a single pass but even this is inadequate at keeping up with most machines in my shed.

I would be very wary about using standard room air filters for metal work as the filters may get gummed up by welding smoke and they are totally inadequate for use with any toxic gasses because gasses will pass straight through the filters.

Room air filters are very useful for clearing a shed of all dust (not just WW dust) to generate clean air for applying finishes, but if anyone wants to control dust while they are working they are far better off addressing the points I outlined above.

I know I must sound like a broken record about all this but I don't want any newbies thinking that a room air filter is the magic bullet. With wood dust there is no magic bullet.

Another evening, another part competed.

I got a couple of 150mm coupling piece from the b* store (damn 150mm bends and joints are expensive!)

Impeller intake
In order to centre the hole on the impeller inlet I'm making, I drew a right angle from the centre of the circle and made a few measurement marks. Then with the coupling resting on top, I can ensure it sits at the same distance from the centre all around, and mark my circle. A bit of rubber strip around the hole, a tight fit for the intake pipe is achieved. I finished up by sealing it all with silicone.

photo (1).jpg photo 1.jpg

I did some work on the timber flange, but have decided I'll just get one made up for me out of steel plate. The piece I was making ended up too flimsy and with far too many gaps to be effective. I'll post my drawings and sketch-up files later of this piece if other's are interested.


Machine port (table saw)
Inside the cabinet there is a flex hose connecting the port to the saw hood. How would I deal with this? Do I need to mangle the saw hood to give it a 6" port, or can I just extract from the cabinet itself. I'll need to seal up the cabinet obviously.

photo 2 (1).JPG
(ignore the sawdust!)

Cheers,
Af.

Originally Posted by Afro Boy

Another evening, another part competed.

I got a couple of 150mm coupling piece from the b* store (damn 150mm bends and joints are expensive!)

Thats the last place I would get them from. I'd be shopping around for these. Irrigation stores are usually cheaper, then plumbing speciality shops, and then hardware store.

Impeller intake
In order to centre the hole on the impeller inlet I'm making, I drew a right angle from the centre of the circle and made a few measurement marks. Then with the coupling resting on top, I can ensure it sits at the same distance from the centre all around, and mark my circle. A bit of rubber strip around the hole, a tight fit for the intake pipe is achieved. I finished up by sealing it all with silicone..

I made mine with a ww lathe. This allows a hole with a rounded edge to be created which smooths the flow into the impeller.

Machine port (table saw)

Inside the cabinet there is a flex hose connecting the port to the saw hood. How would I deal with this? Do I need to mangle the saw hood to give it a 6" port, or can I just extract from the cabinet itself. I'll need to seal up the cabinet obviously..

That's what I would do as a first trial.

Originally Posted by BobL

Thats the last place I would get them from. I'd be shopping around for these. Irrigation stores are usually cheaper, then plumbing speciality shops, and then hardware store.

Yep, got the majority of it from a local plumbing supplier. Still not overly cheap though. ~$20 for a 45º bend. Only got the coupling from the hardware store (it was closer!)

Originally Posted by BobL

I made mine with a ww lathe. This allows a hole with a rounded edge to be created which smooths the flow into the impeller.

I don't own a lathe, but thinking I might try a router to round over the inlet hole and see how that works.

Thanks Bob!

Originally Posted by Afro Boy

Yep, got the majority of it from a local plumbing supplier. Still not overly cheap though. ~$20 for a 45º bend. Only got the coupling from the hardware store (it was closer!)

Ouch!, I'm paying about $10 for these.

I don't own a lathe, but thinking I might try a router to round over the inlet hole and see how that works.

That should be OK, see if you can find one with as broad a round over as possible

I've gotten a friend to make a metal stand and flange for me. Should be ready by the end of next week. I've attached the design files for it in case someone else finds it useful. It's based entirely on Bob's from this thread.

Finished my impeller intake, and the table saw port. The pieces are all mated with rubber and a s#!t load of silicon. I still need to clean up and apply silicon around the outside of the pipes. So, this'll be the last bit of work I'll be able to do until late this week.

roundeover.JPGintake.JPG


table-saw-port.JPGtable-saw-port-new.jpg


Pleated filters
Been looking around a number of places and the only ones who seem to have anything which suits my dusty are woodworking shops. Wondering if anyone has any other leads (espec. in Melbourne) I might try? Thx.



Plans for the motor stand and flange
Attachment 323736
Attachment 323737

Cheers,
Af.

Originally Posted by Charleville

This is not quite a direct answer to the question but it may be helpful in a small way.

My home garage workshop has seen an evolution in my dust management strategy that started with a shop vac, then to a dust collector which was subsequently added to with a pleated filter, then an extra couple of shop vacs added for specific purposes (eg one just for the drill press - very good!) then cyclones on those shop vacs, then a second simple drum stage to the dust collector to collect chips from the thicknesser. Somewhere along the way, I added a whopping big industrial wall fan to blast dust out of the garage door that was being generated by my SCMS. Likewise, three domestic wall fans at key locations keep dust out of my face when using my router table, drill press and SCMS.But, the most impressively performing thing that I have added was pretty well the last in this succession of upgrades and that was an overhead dust filtration unit.


Air filtration Unit-1.jpg


Even if I am just doing metal work in the garage now, I turn it on, knowing that although I vacuum loose dust regularly in the workshop, just walking around stirs up any residual dust.

What makes me so impressed about the dust filtration unit is the difference that I now see in the afternoon rays of light passing in from a western window. Before adding the overhead dust filter, dust was always to be seen in those rays of sunshine. However, when the filtration unit has been running a while, I see none. Highly recommended!


Of course, I now get a bit cocky with it insofar as I found a new way of removing dust from the workshop last week. I just opened both garage doors, turned on all of the outwardly facing fans and blasted away with a small electric leaf blower, blowing all surface dust out of the garage doors. That sure cleaned out the dust under benches and in all sorts of hiding places as well as making the floor look very clean. On the downside, it created a whole fog of airborne dust inside the garage but I just turned on the air filtration at full speed on the longest timer setting and withdrew to let it run overnight. Next morning all of the obvious airborne dust had gone and the whole shop was looking a whole lot cleaner. Yup! - I know that the idea of stirring up all of that settled dust will scare most sensible people but it is done very quickly with a leaf blower so that personal exposure is minimised, time-wise. Better done in rainy weather, also, so that the dust is settled when it is blown out of the garage doors and then hosed off the driveway the next day.Anyway, I just thought that it might be valuable to insert my observations about how effective an overhead dust filtration unit is at removing airborne dust. In hindsight, it should have been a much earlier addition to my dust management strategy before the cyclones, albeit they are terrific for what they do.

I went away and bought myself the bigger version of the dust filter from Carbatec after viewing your post. its gigantic and I am yet to suspend it from the ceiling.

at the moment its sitting on the unused part of the Omga dual saw...
IMG_3730.jpg

Good to see you back posting on the forums Af.

Just wondering where that 6" port is located on your table saw or if it even matters where it goes?

Thanks.

Originally Posted by groeneaj

Good to see you back posting on the forums Af. Just wondering where that 6" port is located on your table saw or if it even matters where it goes?

Thanks mate, getting back into it slowly. The 6" port is located exactly where the old 4" one was. It's out the back of the machine. I'm hoping that this will draw any dust down through the existing saw hood. I'll make a new overhead guard with a 4" port as well shortly.

So today after reading Bob's post on enlarging dust ports, I took off my previous attempt and made a larger opening into the back of the table saw. I didn't have a round-over bit large enough so I made as large a chamfer as I could using a jigsaw. Still need to make the transition between this and the pipe smoother.

photo 1 (1).jpg


Put in place most of the 150mm ducting too. Waiting for the extractor flange and stand to be made and once I have that, I'll pull it all together and post some more pics.

Cheers,
Af.

This is something I didn't do on my 6 inch conversion. Would it make a worthwhile difference to the dust collection or not really worth the extra effort.

Thanks

https://www.woodworkforums.com/attach...1&d=1410087776