Thread: which Dust extractor

Originally Posted by MatMann

I was all set to go for a clear-vue until there stopped being an Au distributer.

If I was you I would wait until there is one.

the 3 main machines all run 5" ports, the biggest being the A3 31 310mm jointer/planer, then a bandsaw and a B3 saw/shaper is about to be ordered.
I'm leaning towards a dual stage unit and to run through 6" s&d still to be setup. It has to be located inside the 7x9 shed.

By 6" s&d, do you mean sewage and drain? If so take a look at stormwater fittings and pipe as it is perfectly adequate for the task and much cheaper.

A Clearvue will have a small footprint but if you have the room you don't have to use a cyclone. A 7 x 9 shed can be adequately serviced by a twin bag 3HP DC but it will take up more room especially as it should be in a sealed cupboard that is vented to the outside. That way leaks and any very fine dust that escapes the filter do not remain in your shed. The other advantage of a cyclone is of course that you don't have to clean filters.

i'm not really sure what to be looking for in a cyclonic dusty so help is truly appreciated

What to be looking for can't really be explained in a WWF post.
I suggest you do a search for and read Bill Pentz site on Cyclone research.

Matt,

I am a Clear Vue owner, so I am biased ... but I agree with BobL ... I understand an Oz distributor will soon be appointed, and I would wait for that event.

So far as I know, nothing combines great airflow with a small footprint and a lack of bags/filters like a Clear Vue. A 3 HP dusty will do a fine job, but it has a significantly larger footprint and as BobL indicated, really should be either located outside the shed or inside a cupboard vented to the outside.

The other cyclones I looked at (Gregory Machinery and Carba Tec) are not as efficient at dust separation as the Clear Vue and need filters, so they take up more room and the filters need cleaning/replacing. Also, they are more expensive. So far as I am concerned, right now the Clear Vue is in a class of its own. I am forever grateful to BobL for explaining that with a VFD I could have a Clear Vue (I thought 3 phase power was necessary, but BobL explained that with a VFD it can be run on a 15 Amp, 240 V circuit).

Strongly recommend you wander through Bill Pentz's site if you have not already done so ... Bill's Cyclone Dust Collection Research - Home

It's worth noting that the Clear Vue Oz site is back up with a Qld contact and prices listed.
clearvueoz.com.au
I haven't spoken to them yet.

Yes, it is up and running again. It has been a long wait and I hope all goes well for Stephen and CV in this country.

Matt
I am in the same position as you In need of a DC
I have look through many DC on the market and many thanks to bobl for his advice to me on them.
I have spoken the new clearvue distributor out here, Stephen and though his pricing is dearer then the US prices it still ok. But he has no stock at this early stage of his set up and is looking at the cost of air freighting parts out
This is making me think now about making my own cyclone using Bill's design from his web site.....But I will wait and see what prices Stephen comes up with.

Russell

Originally Posted by rusel

This is making me think now about making my own cyclone using Bill's design from his web site.....But I will wait and see what prices Stephen comes up with.Russell

Here's one I prepared earlier, under a different guise, before being banned from the forums for having the audacity to be right when a moderator was wrong (he disappeared soon after, dunno where he went...)

https://www.woodworkforums.com/f200/m...parator-33633/

Just re-reading that old thread from 2006 really shows how much we, as an online community have learned and improved our collective knowledge base over the last seven years.

I now have a 2hp impeller and am modifying the lid of the cyclone to take 6" pipe, a project which has stalled partway through due to all the useable space in my shed being filled with my step-daughter's possessions afere we rescued her and her baby from a domestic violence situation a few months back. I hope to soon have some shed-space back and I will post some photos somewhere on here when that happens.

The point is, there are good cost effective alternatives to commercially available products, if you are prepared to use a bit of ingenuity. Incidentally, a 44 gallon drum is exactly the diameter specified for a 1 or 2 hp impeller on Bill Pentz"s site.

I was impressed with what it did on 1 hp, but when I upgraded it to 2 hp but still 4" pipe there was no discernible improvement because the pipe itself was the limiting factor, hence the need to upgrade to 6" pipe.

I hope this may help someone.

Doug

Doug
Nice compact set up
question; The second 44 conected to the first 44 at they mid points What does this second 44 do and how?

Russell

Originally Posted by rusel

Doug
Nice compact set up
question; The second 44 connected to the first 44 at they mid points What does this second 44 do and how?l

Hi Rusel,

The top 44 is the cyclone and the bottom one is the collector.

As the dust is centrifuged out of the airflow by the cyclone, it drops down through the funnel into the bottom drum. The lid of the bottom drum is attached to the bottom of the top drum with an MDF spacer in between for rigidity and to maintain an airtight seal. The expandable band that normally seals the lid onto the bottom 44 then completes the airtight seal and holds the two drums together.

I built a frame around the two drums that incorporates a lifting mechanism so that when the band holding the lid of the bottom drum on is removed, the top drum, with the lid of the bottom drum attached, is lifted off the bottom drum with a 2:1 mechanical advantage and holds it up while I take the bottom drum outside on a trolley and mulch the garden.

There is a cutout in each drum covered by a perspex window. I curved the perspex to the right shape by laying a flat piece of perspex ion the outside of the drums and hitting it with a paint stripper heat gun until it softened and conformed to the curve of the drum. I then bolted them on with foam strip to ensure they were airtight. The window in the bottom drum makes it easy to tell when it is time to empty the collector. The window in the top drum provides much fascination for visitors to the shed who love to watch the shavings go round and round.

Seven years ago it was considered a strong possibility that the static electricity between the plastic pipes and the sawdust may potentially start a fire in the collection bin of particle separators such as cyclones. As I understand it, this is now not regarded as a likely threat, but still theoretically possible. The two perspex windows would have allowed early detection of such an eventuality occurring. To deal with this possibility if it did occur, I also incorporated into the design a hole near the perspex window in the bottom drum plugged with a rubber grommet (from the back of a flouro light fitting). The plan was, and still is, that if a fire occurs in the cyclone, I shut off the impeller, knock out the rubber grommet and stick the garden hose into the bottom drum. The lack of oxygen caused by shutting down the impeller should be enough in itself to stop serious damage until enough water enters to snuff it out completely and there should be virtually nothing in the top 44 anyway.

If this is the path you choose to go down, Rusel, I am happy to provide information/advice/photos of what I have done and what I am doing to upgrade it now (when I get my shed back). The most expensive part was getting the funnel made and fitted, and that was done at "mates rates" by a professional sheet-metal worker who is a personal friend. 44's are cheap secondhand, just make sure you get the ones where the band that fits the lid is released by a lever and not by a nut and bolt system, at least for the bottom drum.

I am quite happy to help any forum members who choose to go this way. My personal opinion is that it ti better than anything that is out there for sale except for a clearvue system, but it will work fine with a 1 or 2 hp impeller and not everyone has sufficient power availability to run one 15 amp appliance, let alone a 15 amp machine and a 15 amp dust collector at the same time. I know I cant, and I know I am better off powerwise than most.

Thats why I like my setup because it does the best I think you can do with 10 amps. (**cringes - waiting for someone to refute this**)

Cheers

Doug

This has been discussed before but I have not presented this graphic before so for those people building their own chip collector they have something graphic to think about.

This general graph shows the flow rate over time of a 3HP DC with and without a chip collector (CC) and with and without filter bags (FB).


The maximum flow one can get is obviously without a CC and without FBs (black line) and the flow rate with use remains more or less constant over time .

Adding a home made CC with 4" ducting to a 3HP DC reduces flow by about 25% (I have measured this) which is the difference between the start of the red and blue lines, and the black and green lines.
The benefit is of course that it is easier to empty a chip bin than a DC bag so the operator erroneous thinks, "Wow this thing continues to pick up chips for months and I don't have to empty the bags". The downside is that less flow means less fine dust is collected at source compared to to the DC without a CC, and this will remain the case until in the case of the non-CC system the bags are near full of saw dust and only then will the flow rate of the DC without the CC drop off to nothing as shown by the red line "full bags" tipping point. Only then will a CC have a greater flow rate than the non CC system, Of course the operator of the non-CC system will quickly see there is a chip collection problem and empty the bags.

Using FB, the flow for both non-CC and CC systems initially drops quickly over time and then slowly degrades - I have not measured the rate of drop offs because I don't make that much dust in my shed.

In the case of well designed and made Cyclone without any FB (since very little fine dust gets past the cyclone) the flow rate loss due to having a cyclone is very small and the green line moves up and starts to approach the start of the red line.

If the CC is inefficient a significant amount (in terms of particles not mass) of fine dust gets past the chip collector,ir hence FBs are still required. The flow rate performance will then drop away just like a regular DC. I have no assessment of the rate of drop off but I do have two end point measurements where the flow rate was about half of that of that expected for those DCs. There was only a thin layer of fine dust covering the inside of the filters but the dust was so fine and compacted that the flow rate was halved. What was worse was no amount of washing was able to remove all the fine dust embedded in the FBs so the flow rate did not improve the flow rate. Theses blocked CC systems were still able to pick up chips so the operator had no clue there was a problem although one operator suspected a problem because he noticed that his shed was starting to be covered in fine dust. Neither of the operators had bothered to ever clean the filters because their bags never got full.

All this means that CC connected to DCs need to be thought about very carefully.
Small home made CCs connected to a DC are basically a waste of time for controlling fine dust.
To maintain flow rates and collect fine dust the FBs on systems with CCs still need to be cleaned regularly - I suspect more regularly than if you are not using a CC - but given that bag cleaning is so messy you might as well empty the bags while you are at it.
If you are occasionally making a lot of chips then by all means take advantage of them but be aware that they do not grab fines dust as effectively. If you are not making chips and making a lot of fine dust like sanding you will be better served by removing the CC from your system as sanders will clog FBs and slow down flow rates even faster than other dust making methods.

The same is not quite so for VCs. The flow rate losses are less than 10% and BUT like a DC they will continue to collect chips even at reduced flow rates and the operator has no clear way of knowing if the filters are blocking up so the filters still need regular cleaning.

Bob
The example you are using here is where the exhaust is inside the shed? How does this work for a cyclone and no filters and the exhaust being out side away from shed opening?
Russell

Originally Posted by rusel

Bob
The example you are using here is where the exhaust is inside the shed? How does this work for a cyclone and no filters and the exhaust being out side away from shed opening?
Russell

I'm not sure I understand your question. Provided it is not too constrictive adding an exhaust to a cyclone makes no significant difference to the flow rate as the limitations are on the negative pressure side.

Cheers
Bob

Bob
What I am try to ask is if the exhaust from the fan that is on top of the cyclone as in the CV setup goes out side instead of a filter bag inside then you should not get any fine dust inside..am I correct in say this?

Russell

Originally Posted by rusel

Bob
What I am try to ask is if the exhaust from the fan that is on top of the cyclone as in the CV setup goes out side instead of a filter bag inside then you should not get any fine dust inside..am I correct in say this?

Russell

That is the way I do mine Rusel. The stack of 44's are near the window, with the impeller on top. The exhaust air from the impeller goes straight out the window through a plywood board with a hole in it the same size as the exit pipe.

It is potentially possible for some of this air to be sucked back into your shed, after all you are pumping an awful lot of air outside, so air will come in somewhere. I watch out which way the wind is blowing and if it is coming towards the front doors of the shed then I will keep them closed.
In any case, the air that was just ejected with the fine dust in it will dissipate even on a relatively calm day and a high proportion of the air entering the shed to take its place will be clean, outside air.

I hope this helps

Doug

Originally Posted by rusel

. . . . should not get any fine dust inside..am I correct in say this?

I assume you mean fine dust that has been separated out by the cyclonic action - if so, correct.

But for all DCs the issue of the fine dust at the collection point still remains

On a big/powerful/efficient system like a Clearvue, provided large ducting is used the pressure drop induced by a cyclone is relatively resulting in only a small loss in flow, so that it still collects most of the fine dust at source. OTOH if a Clearvue is connected to a machine by a 4" piece of flexy it will still only pull ~400 cfm so it will not be able to grab the fine dust at source.

On smaller DC systems that are already borderline at collecting fine dust, adding an inefficient cyclone or CC an easily drag the flow down to the point where fine dust collection at source is compromised.