Thread: Wheelie Bin Cyclone?.

You might get some help from my midi cyclone that also uses the 2 bag dust collector and wheelie bin as a receptacle for the main dust.

In particular the photos in post 8 seems what you are looking for.


Peter.

Tim, we have done that at the club I am a member of. Carbatec cyclone (second hand), vfd, double stack filter and a wheelie bin. If you want I could ask for some details. I know we raised the height to accommodate the bin.

Or, I have used a drum to create a separator with my 2 horse dusty. It now lives in it's own shed behind my new shed, for noise and dust reasons - no nose full of weird coloured mucus

100% of this I have already repeated, but let me repeat it again.

Assuming 1000 cfm can be generated by the impeller/motor available, the 4000 fpm is purely duct size dependent which is why the 1000 cfm at source is really the nub of the problem.

A 3hp motor and 13" impeller with clean bags/filters can generate ~1250 cfm in a 6" duct and hopefully something close to 1000 cfm at the source (ie the machine) where the dust is made. Maintaining this flow requires the bags/filters to be kept clean which is not easy especially if large volumes of sawdust are produced. If the bags are not cleaned this will easily reduce the flow.

If the clean bags/filters are replaced by a home made cyclone this may immediately use up to half the pressure generated by the 3HP/13" impeller thus dropping the starting flow below 1000 and closer to 900 cfm before even hooking up a machine to the ducting.

All this is why BP starts with a 4HP motor, 15" impeller before he adds a very carefully designed cyclone that not only does a good job of filtering the saw dust, but also generates a low back pressure to help maintain higher flow rates than virtually all other cyclone designs. His cyclone design loses 2.25" of WC, compared to most other cyclones which require as much as 5" WC to operate. A cyclone made by using bits and pieces from commercially available DCs will be in that category.

It may be possible to design a low back pressure 3HP system but it will still not be low enough to produce 1000 cfm at source otherwise BP would have done this. I believe his real preference was actually a 5HP/15"/60Hz system to really make sure he had 1000 cfm at source.

Assuming external venting, with 3hp systems there are basically two choices.

1) Use a cyclone and settle for a lower CFM.
This will result in a shed that will contain more suspended dust in the air and eventually landing on surfaces to keep the shed in a contaminated state.
This can be partially compensated for by scrubbing the air in the shed of fine dust by running the DC for some time after the last dust making activity.
This may suit people who make more sawdust and don't like cleaning bags/filters

2) Use bags and keep them clean
This will result in a shed that will contain less suspended dust in the air.
I would still advocate scrubbing the air in the shed of fine dust by running the DC for some time after the last dust making activity.
This may suit people who make less sawdust and don't mind cleaning bags/filters

The final collection and management of the dust by wheelies or plastic bags is really a secondary consideration as pretty much any of these can be added to any system as required.

Believe me I hear you Bob and the import of what you say isn't lost on me..(or likely others).

I think some of us maybe when starting out - just can't afford 3 phase, and 4 or 5 hp engines, and 16 inch impellers, & 8 or 10 or 11 inch ducting etc.

There's no question, that's what works.

I guess if I was really prepared to spend the time and $ - I could haunt somewhere like Bills Machinery up there on Gnangarra road, and try to buy a suitable sized (16 inch) engine and impeller of some kind - maybe out of a commercial dust extractions system...

I already have the 3 phase on, so could run such a system... assuming my 6mm^2 3 phase cable would supply the herbs needed over the 30 meter run from the mains box.

Perhaps I could even build a suitable sized cone from staves (not unlike a wine barrel).
Perhaps I could buy again from Bills used Machinery some metal HVAC type ducting tube...
I could probably cobble something together incorporating the wheelie bin/s, as the dust receptacle.

Eventually thats probably the way I will go.

For now I have a 1600 watt household cyclone vac cleaner stuffed into the 2 inch outlet on my table saw and empty the little 2 liter bowl every 5 minutes of use of the machine and nothing at all on the thicknesser or jointer.....so for me - (while I do the couple of little jobs I have to do to pay for my power connection and other tools I need), I have to find an affordable "temporary solution" to get me thru.

I have been offered another small week long feasibility study consultancy job up the coast again - (~ $ 2k) worth - so I am hoping that will cover the majority of the cost of a CVM in due course once its done and out the way, assuming it comes to fruition.

The trouble is Bob - that my bank accounts hemorrhaging after building the shed and buying the machine and all the parts that were missing from it, and spindle molder tooling, and now the 3 phase power connection.

So at the moment I am pretty tapped out and have to work at the cabby trade again, to get ahead for a while... and need to get bye until then, so a second hand 2 HP dusty will be in my immediate future as a stop gap while I generate the $ needed for a CVM.

If I get the time, I might mod the 2HP dusty, if the ducting etc will be used later by the CVM, and it doesn't cost a lot to do..

I am sure theres a reasonable market out there for a cyclone based 3 hp dusty of the ilk of Sturdees construction thread, for the home handyman / workshop around $500 - $1000.

The current crop of bagged dustys at 1, 2 & even 3 hp with small 13 inch impellers just aren't up to the task for what they cost BUT - we all have to start somewhere!.

I'm already thinking - that I'd like to sell my machine and get a new one with scribe saw and sliding table etc... capable of breaking down 2400 x 1200 sheets - but that's probably because I am missing all the machines (Altendorf panel saw) & stand alone machines - that I once owned.

I will get there Bob, but I do have to undergo my own journey....one foot in front of the other, at my own pace.

Even you yourself have a twin bag dusty, - not a BP type cyclone, so those of us, with only modest means, will have to get to the CVM stage in a series of small steps within our individual means.

I'm greatly encouraged by Sturdees efforts within his constraints space wise.

Even the CVM doesn't float my boat due to the collector... A wheelie bin makes a heck of a lot of sense from a convenience factor...but the combined height of the bin itself and the cyclone cone - mean something thats too loud and visible to all the neighbors.

Those 2 factors alone would tend to make me consider spending a similar sum or investing a lot of time and effort - building something else.

For all of BPs excelent work - he's come up with a fantastic empirical solution, that would be a visual amenity and sound pollution (possibly air pollution as well) problem, in most urban back yards IMHO.

There simply has to be a better answer.

No questioning The CV and CVM will suck a golf ball thru a garden hose... but if the other factors (cost and visual amenity and sound and dust emissions) weren't an issue - heck I'd just employ Monica Lewisnki on a full time salary and 457 visa to sit in my backyard and take care of all the dust!

The CV and CVM are the right solution, technically speaking - but they just won't fit most folks urban circumstances is my suspicion Bob.

There has to be a way you can park a units along side your shed, within the 1 meter minimum setback space off fencelines, and below 1.8 meter fence height, and without driving the neighbors nuts with noise and dust.

CV & CVM isn't a one stop shop solution for me in my individual urban circumstances.

I don't want the shire round here closing me down....

Sound levels, dust & visual amenity will all be issues for me.... what i can keep hidden from view, out of sight, and quiet as a mouse, with zero dust, in the 1 meter gap between my shed and fence, will work for me... and CV & CVM just don't measure up in those areas regardless of how good their suction numbers might be.

I may have to tradeoff suction numbers in order to satisfy the other requirements. Space inside the sheds an issue for me so enclosing the CV & CVM within the sheds not an option long term.

How one gets a cyclone above a collector receptacle, (and maintains 1:1.64 cylinder dia / height ratio, in less than the height of a 6 ft fence.... I don't yet know... but there has to be a way...

I may yet work backwards, start with the smaller 120 liter wheelie bin...and work out what height I have left - and using the BP ratio design a cone and cylinder at the right ratio to finish at fence top height when stacked on top of the wheelie bin!.

Maybe I need to redesign the wheelie bin to be shorter and fatter...to gain the cyclone height I require.

All things I will chew over as I work out my own solution I guess.

Thanks again for all the responses.

I have seen more than one attempt to use a wheelie bin under a cyclone with only limited success due to air leaks within the bin and sealing the top. Why does the cyclone have to be situated outside the shed? Noise is not a valid reason as they can be silenced down to about 72db which is comfortable enough to enable talking to take place at a normal level. Each to his own and the best of luck in your endeavours.

Why must the dust collection receptacle sit under the cyclone?

I imagine that centrifugal force and gravity, separate the dust from suspension in the airstream!.

The speed of 4000 fps inside the ducting keeps everything in suspension.

When the air is then spun via the ramp and cone inside the cyclone body - it effectively enters a large volume allowing it to slow down, such that the heavier particles drop out of suspension and fall by gravity to the dust collection bin. I imagine the fine particles are spun to the outside of the cylinder and cone via centrifugal force, where eventually they slow due to friction - to the point they too fall into the bin at the bottom.

This requires a cylinder & cone of sufficient volume and thus height and diameter for the expansion of air to allow it to slow...such that particulates fall... and THIS adds up to a tall structure. It's a physical requirement.

Then stand it on top of the dust collector and it pokes well up above most 6 foot urban fences.

So..

Why does the receptacle HAVE to be located UNDER the cone?

Couldn't the cone finish down near ground level, and the same (or a 2nd smaller) electric engine drive a small conveyor that lifts the now settled dust, UP from ground level under the cone - into a receptacle located ALONGSIDE the cylinder and cone?



I guess I just don't accept that a cyclone has to be almost 3 meters tall to work - yes its the easiest way but as Keating once infamously said - "Life wasn't meant to be easy".

To me at least its dumb to put blowers up so high in the air that the things top heavy and can't be serviced from ground level and looks ugly to neighbors on to of expelling the air and noise at a height where it can't be controlled easily and is more likely to annoy neighbors.

Just because that's how they do it in light and heavy industrial areas doesn't mean we should do the same at home.

We can't erect wind turbines up on urban block, due to the noise pollution and visual amenity pollution, but out in the country you can have acres and acres of them.

Same with this Cv & CVM rocket ship crap.....

Sorry but someone has to say it.

It's not suited to the market its trying to be sold too IMHO.

Unitize it, make it around 6 foot tall max, and with a 500 mm wide max foot print - and you'll have a product the home handy man might be able to use and get away with.

I don't accept the need for red flashing lights on it for the planes to deviate around it at night!

Good design.... and not "the easy way out" has to be the answer surely!

If it's taller than a person - it's too tall!

I see no reason for it to be that tall - if not a conveyor, a simple augur system would work equally well to bring the unit down to something approaching workable height IMHO.

Given your reasons I would recommend that you definitely do not buy one. You and Soundman should get together and design your answer to the current accepted best practise.

the current accepted best practise.

Or the only "one size fits all", "take it or leave it", "buy what have on the shelf" product?

At the moment it's the Model T Ford of the cyclone DE market, you can have it in any color you like as long as its black.

Sorry to be negative Chris - this isn't a CV or CVM thread, - it's a wheelie bin dusty thread...because as a potential customer I see short comings that for $2.5K plus that wouldn't suit me in an urban area.

It's just to tall, and too noisy, and the dust receptacle isn't "convenient enough" to wheel away and empty / replace etc.

I consider these 'design faults' for what I need in my situation - and I fully accept that, "others mileage will vary".

I happen to think that the design of BP's cone and cylinder and flow rates etc are all spot on.... I'm not disputing those aspects - just the ones where it must be so tall and un-weildy...and inconvenient for dust removal / emptying.

Why can't it be unitized, so that buyers can assemble it to their own requirements?
Why shouldn't people make their own if they can't buy what they need off the shelf?
After all BP provides all the details on line at his website for people to do just that (make their own).
IF the CV requires a VFD - to spin up to the required rpms with 60 htz instead of 50htz - and they are cheap etc - then why doesn't it come standard with the VFD already mounted and wired in?

I guess my feeling is that a $2.5 K machine should be designed and supplied plug n play ready to use in the market it's being sold in.

Maybe in due course it will be.

Right now - the amount of work required to make CVM "fit" my situation - I might as well spend that $ and start from scratch based on BP's specifications, and make something that does fit.

At the height of the standard CV & CVM - I require written approval of my neighbors, submitted to council - to be allowed to install it in my yard!. I know this coz when applying to build my shed, I had to get their approval to build it as designed on the plans coz it's above the allowed height at the ridge line - bye ~ 100mm or so - even tho I meet the required setbacks from the adjoining fence.

The CV & CVM will fall into the same category....
I don't have to get shire approval on anything at fence level or below...

Short of digging a pit to locate my CV or CVM into - to drop it down to 1.8 meters.... which then creates problems getting the dust out, I can;t see any way to make it work easily.

Others mileage obviously differs, ours is one of the toughest local govt shires in Perth...many other local govt areas in Perth are much slacker.. ours are like little Hitlers..... its far better not to get them on your back in the first place... and a CVM in standard form will make me a target.

I suggest things will only get worse in this respect around the nation as local govt all copy each others rules and regs over time.

I have the space for 3 or 4 wheelie bins, all alongside each other, so a unitized cyclone, muffler, filter, and dust collector all stood alongside each other at 1.8 meters height or less - works for me.

That's whats behind my present reticence to purchase a CVM at the moment.
There has to be a better way IMHO.
I'm not a one size fits all type of bloke unfortunately.

Maybe something worthwhile will come out of my attempt to unitize a dust collection system... and keep it simple and within size height and sound constraints.

I'm not in a hurry with it, I can have a go at one stage at a time until I get it right and how I want it.

It might well fail, - it wouldn't be the first (or last) time.

The way I look at current hobby level dust extractors is like the range of 1960s VW engines.
The fundamental designs are such that make it impossible to get 1990s VW Golf engine level type performance from theses older designs.
Some gains can be made by rearranging the parts (as shown by my Generic 2HP DC thread) but no matter what is done rearranging the parts of a bunch of VW's engines still generates a 1960's (or older) technology machine and any performance ceiling will quickly be reached.

Spinning the impeller faster is one way to get an immediate increase - the easiest/cheapest way to do that is 3 Phase.
Electric motors are already close to maximum efficiency meaning the only way to increase the amount of work they can do is to increase the HP of the motor.
Any fluids engineer will tell you the current crop of DCs use 1960s impeller designs. To gain any significant improvement in air collection efficiency newer impeller designs are required.
Given what we now know about wood dust, higher efficiency air filtration systems that can handle high flows with minimal back pressure and release the smallest amount of fine dust are an essential part of a 21st century DC.
Humm . . . . . . sounds like reinventing a BP cyclone.

Does the impeller have to be physically located ABOVE the cyclone; is there any reason why the outlet from the cyclone can't chuck a U-ee and have the impeller sited next door?

On a similar theme; can the impeller be fitted BEFORE the cyclone? Ok, there is now the issue that the cyclone and wheelie bin are now under slight pressure rather than a partial vacuum so new problems need to be overcome, but surely the concept of cyclone separation relies purely on fluid flow? A full bore pressure relief valve can be home-made and fitted in case of a blockage.

I addressed the wheelie bin with my past experience of seeing it tried with only partial success. I repeat what I said, don't buy a cyclone as it will never work for you.

Originally Posted by Chris Parks

I addressed the wheelie bin with my past experience of seeing it tried with only partial success.

Then you have not looked far enough and base your opinion on insufficient data as my wheelie bin lid construction is 100 % airtight. I actually have to use a screwdriver to wedge it open by breaking the airtight seal.


Further there is no real need for the impeller to sit on top as mine doesn't. Maybe there is a slight loss of suction, which I doubt, which can be boosted with a cheap in line fan and motor to boost the suction. I use 2 cheap GMC 1 hp units, without bags to boost the system and allow for longer runs.


May not be what the purists think it ought to be, but it works and was cheap. Don't forget there are always more ways then one to solve a problem.


Peter.

I addressed the wheelie bin with my past experience of seeing it tried with only partial success.

Chris your not doing your reputation or that of the CV units any favors here with these negative comments IMHO.


Micronair supply a unit specifically that takes wheelie bins and uses them as the receptacle!.

If they can do it, others (including your good self perhaps) should perhaps be able to do so also.

Sturdee's effort seemed to work admirably also!.

That's at least 2 using the wheelie bin successfully.
Why the negativity?

Maybe your past experience is invalid?

Maybe something along these lines.... scale up the size of a plastic cylone unit on top of your wheelie bin, stand a 3HP dusty on the ground next to it, and connect the ducting.

This was sort of my cheap $500 Wheelie Bin Cyclone idea.... not the magic numbers, and not intended to be a replacement for CV and CV Max.

Just something that the average bloke can pop in a small lean too against his shed between the fence and get started without breaking the bank.

It's just a concept at this stage.... but really - how hard can something like this really be?

Sturdee's excellent thread proves that it can be done if your determined enough.

It's never going to be a CV or CVM replacement - more of a stepping stone along the way there.

I have a suspicion - that if a injection molded unit scaled up from whats depicted here, were available to fit straight onto a wheelie bin and wood workers could but a second hand dusty, and couple it all together - run some 6 inch PVC ducting....that MANy wood workers would be far better off than they are now...from a dust management point of view.

Certainly not the perfect answer - but not everyone drives mercedes, bmw's, ferrarri's and rolls royces either...

Some of us have to cut our coat according to our cloth.

We all have to crawl before we walk and walk before we run.

BP can design the perfect DC cyclone, but not everyone has the US standard of living to afford the very best of everything.... there has to be a starting point.

Something that can get you started and let you earn enough to eventually upgrade to something better.

That's what I am aiming at... a nominal $500 budget and commonly available / parts (like wheelie bins)... and 6 inch PVC...and second hand dustys...

I'd be elated with something like that, over what I have now!

Others mileage obviously varies.