Thread: Hafco DC3 Dust Extractor

Thanks again Bob. Your knowledge on the topic astounds me.

I didnt actually know there was a dust forum but can see that a moderator has moved this thread to the right location.

At the end of the day whatever I do is going to be a compromise as I am very limited in space. As you can see from the picture the space I am working in is about 2 metre by 5 metre and it is optimally configured to make maximum use of every space. I have no option to mount anything outside or put a window in.

Originally Posted by BobL

Instead of Flexy for corners use 2 x 45º ducting connectors, if you do your research it will cost you less and work better than the flexy.

Thanks for the feedback and I will see if I can make it work

Originally Posted by BobL

Instead of a T use a WYE connector and a 45º bend to get the 90º on the leg of the T - they are much more efficient than a T.

Great stuff. Had just worked that out after my post. Carbatec have a great starter pack that has 6 meter of flexi, 4 blast gates, Y connector etc etc for $100.

Originally Posted by BobL

Use PVC duct and a 2 x 45º bend instead.


In this case using flex won't matter as the 3" Dewalt is seriously throttled anyway.

Too easy.

Originally Posted by BobL

Sorry but there is NO WAYl a 2 Hp DC connected to 3" ducting have 10 times the flow rate of a Kingchrome shop vac.
The Kingchrome will have about 100 cfm through a 2" duct - a 3" duct on a 2HP DC will have a MAX of about 200 cfm (less if you use flexy).
So your improvement in flow will be less than 2x. Remember you need 1000 cfm to collect fine dust at source so I predict significant disappointment in your proposed system - yes it will collect some chips but you will have more or less the same dust fall out over time as you have with the Kingchrome.

Kincrome report suction of 40l/s or 85CFM. 200CFM from the proposed 2Hp system would be disappointing indeed however I am not sure what my real options are given my space (and to a lesser extent budget limitations). I think I should be able to mod the DeWalt to take a 4" connector and possibly the Lanisher too. As suggested this should take me to 350CFM.

Hi John

Thanks for your time in joining the discussion

Originally Posted by John Samuel

Damienol,

What are you trying to do? Is your aim to collect the chips; or is it to grab the great bulk of the very fine (invisible) dust that is the health hazard? No system can be described as good or bad until the aim is stated.

About seven or eight months ago I was wading through chips and dust and decided to do something about it. I thought a 2 HP dusty would easily do the job, but my reading of Bill Pentz's and BobL's stuff soon made me realise that this was not the case. I started by drawing up a wish list for my dust collection system. It is as follows:

1. I wanted a ducted system so I was not dragging machines around the workshop. That meant I needed a 6" or 8" ducted system.
2. I wanted to vent outside, so even the superfine dust was removed, and so I was protected against leaks.
3. I wanted a small footprint (so I could keep the system in the shop and did not need to build a shed outside for a dusty).
4. I wanted to achieve the magic numbers of 1000 and 4000 so I had a shot at capturing the very fine material and at avoiding clogged lines.

My objectives would be as follows:
1. I want a static ducted system with pipe runs to each of my main systems. That is, I dont want to have to move my machines around as space and floor does not support this.
2. I want a small footprint as space is extremely limited.
3. I want a system that can be contained within my mancave and does not require anything to be installed externally
4. I want to capture all woodchips and enough of the fine dust so my health is not at risk
5. I want a significantly better solution then what I have today with my shopvac
* I wish it would be super quite ;-)

Originally Posted by John Samuel

The problem most woodies face is cost. Once you have read the research on dust collection, installing a 3 HP dusty or a 4 HP cyclone with 6" ducting are the glaringly obvious solutions, but they are more expensive than a 2 HP dusty.

While budget is a concern my main constraint is space

Originally Posted by John Samuel

When our budget limits us to a 2 HP dusty (it often does) then to do a good job we need to follow BOBL's advice. Get a machine with a 6" inlet (or one that can easily be modified to use a 6" inlet), use a short section of 6" flexy and move it to the WW machines as required (or move the WW machines to it).

Do you have a list of these system. I have only been able to find the Carbatec and Hafco systems which I understand from Bob are pretty much identical. Price and colour being the only difference. (Hafco is currently $60 cheaper)

Originally Posted by John Samuel

Finally, BobL makes a critical point when he says you need to modify the machine ports to take 6" ducts. A few ideas can be found here ... https://www.woodworkforums.com/f200/m...chines-161166/

That is insane. He must seriously hate dust.

Originally Posted by John Samuel

In my case I did a dummy spit and wanted a complete solution that would see me off the planet, and so did SWMBO who was tired of my dust getting into the house. The cheapest solution that met all of my wish list was a Clear Vue cyclone. In fact it was the only solution that ticked all of the boxes on my wish list. It is a great unit that would suck start a whole fleet of Jumbo jets and it has a tiny footprint (about 700mm X 700mm). But it was more expensive than a 2 HP dusty.

Do you have details on any online stores selling these? My quick search only revealed an $1800 system in the USA

Originally Posted by Damienol

Great stuff. Had just worked that out after my post. Carbatec have a great starter pack that has 6 meter of flexi, 4 blast gates, Y connector etc etc for $100.

Those starter packs are really just to get you started. The problem with the fittings in these kits is they fit poorly inside flexy or ducting thereby constricting the diameter of the flexy. The blast gates are even more restrictive because they don't fully open. What these starter kits end up doing is restrict the flow in 4" ducting to about 300 cfm. But they do get your started.

A better solution is to use stormwater wyes and connectors which fit on the outside of ducting, or the ducting fits (with a bit of effort) inside these fittings thereby retaining the 4" diameter. In the case of blast gates Chris Parks had some reasonab;y priced full size ones, maybe he can direct you to where to get these. You can also make your own very easily with MDF. This means you can make them the full 4" in diam so you won't lose any flow.

Originally Posted by Damienol

Hi John

Thanks for your time in joining the discussion

My objectives would be as follows:
1. I want a static ducted system with pipe runs to each of my main systems. That is, I dont want to have to move my machines around as space and floor does not support this.
2. I want a small footprint as space is extremely limited.
3. I want a system that can be contained within my mancave and does not require anything to be installed externally
4. I want to capture all woodchips and enough of the fine dust so my health is not at risk
5. I want a significantly better solution then what I have today with my shopvac
* I wish it would be super quite ;-)

So far as I know, you have just specified a Clear Vue Cyclone. BobL may have other options.

To allow static ducting that will not clog and that will capture fine dust you need a min of 1000 CFM (volume) at 4000 FPM (velocity). To do this you will need a 3HP dusty or a 4HP Cyclone and 6" ducting. For research on this subject see Bill's Cyclone Dust Collection Research - Home

3 HP dustys have a large footprint, so too do most cyclones. That's one reason I opted for the Clear Vue.

The Clear Vue normally requires an 8 ft ceiling, but trials in the US show it can be installed on an angle in shops with low ceilings. For more info drop Clear Vue in the US a line. Contact us - Clear Vue Cyclones

As I understand matters, a new Oz Clear Vue distributor will soon be appointed. I paid about $2,250 for mine, plus a VFD (about $300) so I could hook it up to a 15 Amp, 240 V electrical supply (getting 3 phase into my shop was much more expensive, the VFD allows you to run it on 240 V).

I got my Clear Vue's noise levels down to about 65 dB. That is not super quiet, but it is quieter than nearly all my machines, including my shop vac.

If you don't open out machine ports to 6", you throttle the airflow at the machine and don't get the necessary 1000 - 4000 figures. This means you won't capture the fine dust and you are at risk of clogging lines. It also means you have spent much of your money for nothing. The cyclone will move a ton of air, but with (say) only 4" ports you will get about 400 CFM instead of 1000+ CFM. Sorry to be the bearer of bad news, but the physics are that at the velocities we operate at air hardly compresses at all, and any restriction throttles the air flow even with a monster impeller fitted.

The only equipment I know of that will meet your wish list is a Clear Vue Cyclone. Even then, you will need to get the 8" exhaust vented to the outside. Mine goes through a window, but others have punched a hole in the wall.

Originally Posted by Damienol

My objectives would be as follows:
1. I want a static ducted system with pipe runs to each of my main systems. That is, I dont want to have to move my machines around as space and floor does not support this.
2. I want a small footprint as space is extremely limited.
3. I want a system that can be contained within my mancave and does not require anything to be installed externally
4. I want to capture all woodchips and enough of the fine dust so my health is not at risk
5. I want a significantly better solution then what I have today with my shopvac
* I wish it would be super quite ;-)

An admirable list but given your specific space requirement unless you are prepared to make or have made a custom made cyclone, there is nothing out of a box that meets these specifications. Even a custom cyclone is only part of the answer to specification 4 . All machines will need to be modified to utilize one 6" port, or 3 x 4" ports, or one 3" and one 5" port to meet this specification.

As mentioned in another thread the Clear Vue Oz site is back up again listing prices with a Qld contact. Have spoken to them yet.
clearvueoz.com.au
Prices look the same (though freight will go up for me).

Originally Posted by BobL

An admirable list but given your specific space requirement unless you are prepared to make or have made a custom made cyclone, there is nothing out of a box that meets these specifications. Even a custom cyclone is only part of the answer to specification 4 . All machines will need to be modified to utilize one 6" port, or 3 x 4" ports, or one 3" and one 5" port to meet this specification.

As with most things in life compromise is a necessity.

I need to keep this all in perspective. I am a hobbiest. I get about 4 hours a week to spend in my mancave.

Taking everything on board and taking as much of the excellent advice I have been give here I am going to do the following tomorrow:

Purchase a 2Hp system. I will visit CarbaTec first to see if they can match the excellent deal H&F have offered me on the DC-3
Purchase the carbatec pipe starter kit
Head down to bunnings and buy 100mm pipe with 45 bends and Y connectors galore.
Run 100mm pipe to all parts of my workshop and limit the use of the flexi.
Mod my Lanisher and thicknesser to accept the 100mm flexi.
Only use 3" for my drop saw

Thanks again for all the help

I forgot to add that if I am not happy with the results I will look to upgrade to 150mm pipe or sell the unit for a moderate loss and invest in something more powerful

Good luck with it.

I have two more suggestions you might like to think about.

The first one is to see if you can move the impeller on the DC so as to remove the 5' flexy connection between the impeller and the filter.
Like this


Then see if you can replace the 2 x 4" intakes with 1 x 6"

Then see if you can rotate the impeller as shown in the diagram below so the intake is vertical (it won't poke out into your shed space either )

Then use a short length of 6" ducting as shown by the yellow ducting.
About 1/2 m of duct, then a 90º bend (preferable 2 x 45º bends) Then a 6" diam Y.
At the end of the Y use a 6" to 4" Adapter (They are called Level Inverters) and after that go with the 4" ducting as per your proposal.
On the side arm of the Y add a blast gate (BG)



This won't change anything when using dust making machinery BUT when you finish using a machine open the BG on the 6" Y and your DC will pull more than 1000 cfm which will quickly clear the shed air of fine dust. You might also be able to leave the 6" blast gate partially open without significantly affecting the draw on the 4" line. I can do this with my setup if I am drawing on one duct smaller than 6".

If you leave the DC in the stock configuration even with the two 4" ducts open at the impeller ie you will have to pull away the ducting from the impeller you will only get ~700 cfm of ventillation (still worth doing)

It's a fair bit of effort and expense to go to but then you have half set yourself up to go with the 6" ducting!

Hi Bob,

While I understand the theoretical benefits of using 2 x 45 degree bends instead of 1 x 90 bend, most stormwater 45 adapters seem to be more of a kink than a curve, with a sharp crease on the inside edge. Whereas, the 90 adapters have a smooth cradius both inside and out. Has this been tested empirically by anyone?

Gavin

Originally Posted by hiroller

Hi Bob,

While I understand the theoretical benefits of using 2 x 45 degree bends instead of 1 x 90 bend, most stormwater 45 adapters seem to be more of a kink than a curve, with a sharp crease on the inside edge. Whereas, the 90 adapters have a smooth cradius both inside and out. Has this been tested empirically by anyone?

Gavin

On any bend the restriction to flow is primarily caused by the air hitting the outside radius of the bend so by far the majority of the flow is on the outside radius. As long as the outside bend wall is smooth it should be ok. A sharp crease on the inside radius has little impact on the flow however this edge sometimes has bits hanging off it which should be removed - I use a bit of sandpaper on a cork roll to do this.

The idea with the two by 45º bends is to give it a wider radius of curvature so that the air hits the outside radius with more of a glance than the 90º bend. The benefits at are marginal especially at low air speeds but with small DCs every little bit counts.

Some people will go to insane lengths to reduce losses in their ducting ...
IMAG0021.jpg

Originally Posted by John Samuel

Some people will go to insane lengths to reduce losses in their ducting ...
IMAG0021.jpg

One thing that amuses me about this picture is the fancy plaster architrave - it must be a really fancy shed

Bob,

When we built the place I could not put up a steel shed because there was not enough room for the required breezeway between the shed and the house. So, the only way I could get a shed was to make it part of the house structure to eliminate the breezeway. The construction spec said a certain cornice would be used "throughout". It never occurred to me that this would include the shed until it went in. So yes, it is a very fancy shed ... plaster walls and ceilings and fancy cornices.

One of my mates took one look and declared that it was a doll's, house and not a shed. I banned him for life, until he spent an hour in my shed holding a doll. He did, and is now allowed back in. Had him over a barrel. He liked to drop in occasionally and use some of my gear.

IMAG0271[1].jpg

Despite it being "pretty" here is the sign on the door from the house to the shed.