Thread: Dust Extraction

Thanks David
I have been looking at both machines was wondering the same sort of questions
Regards Michael

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I'm too far away to have much to say about the machines you are looking at.

Your plan to split the 6" duct into two 4" ones has flaws in it. To get the same airflow as a 6" pipe you need three 4" pipes. So even if you left both branches open all the time you would still be throttling your dusty down. You will get the best out of it by running all 6" ducting throughout the shop and having a shutoff on the two branches so you can select either / or as needed. Run the 6" to every machine and open the ports on the machines wherever possible to take the 6" pipes / hoses. The shut offs for each machine should be along the main branch line is possible.

Also beware of the airflow claims the sellers make for their dust collectors. They are tested with just the motor and blower only. As sold they are lucky to produce half the claimed airflow when installed in the shop.

Pete


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Originally Posted by Dave Reed

I've been looking at upgrading the dust extractor (1 hp portable) to a fixed unit outside the shed and ducted to a number of machines (lathe, bandsaw, mitre saw etc. I plan on running 6" ducting into the shed and splitting the duct into 2 runs of 4" each approx 3m long, minimising the number of bends as much as possible and using large radius curves to minimise airflow loss. I also plan on using shut off gates for each machine outlet

4" ducting runs are almost complete waste of time. 4" ducting can only carry at best 430 CFM whereas 6" can carry around 1250 cfm, although as the runs get longer and junctions are added the flow goes down from there.
To service machines with 4" ducting and get the same flow as 6" ducting you need 3 x 4" independent ducts.

In the case of a TS a 6" duct can be split at the machine with a 6" to 6"/4" Y - the 6" goes to the cabinet and the 4" goes to the guard. This directs more flow to the cabinet as poised to the guard.

To get the benefit of a powerful DC you HAVE TO run 6" all the way to the machine.

Now once again its no use connect the 6" up to the usual 4" posts on machines so you have get your angle grinder out and open up the 4" to a full 6" opening.
In addition if the machine uses an enclosed cabinet another opening has to placed into the cabinet to allow air in so that it can sweep the dust out.
Most woodies don't like to hear that but unless that is done you might as well not bother with 6" pipe.

Looking on the Timbecon and Carba Tec websites and they both have 3 hp units with around 1900cfm. There is a major difference in price ($1500 for the Carba Tec unit and $600 for Timbecon) I know you get what you pay for but does the Carba Tec unit work that much better than its cheaper cousin.

Aa QC says the manufacturer quoted flow rates are somewhat meaningless and everyone has been fudging their figures up over the years.
Bear in mind it's largely the ducting and machine ports that determine the flow rate.
The CT machines are perhaps slightly better made, so they might have better performance under load, have a longer lifetime so won't leak as much and are maybe a bit quieter. Whether these things are worth the extra money is up to you to determine.

The other KPI is "static pressure" as this and the fan pressure curve and impeller design is what determines the dow und
er load.If you notice the two Timbecon 3HP DCs claim 14" and 22" of water pressure. While I am very skeptical of the actual numbers there is no doubt the more expensive will have the higher pressure generating capability.
The more expensive DC has a shorter and less convoluted pathway between the impeller and the bag housing so this is what you are paying for. If needed the more expensive DC can also accomodate 8" ducting direct into the impeller
The less expensive DC is a very old design (1960"s) where as the other one is a 1980s design.

If you want to come a see how I set up my DC, modified all my machines etc you are welcome to come and take a look.
Same offer goes for anyone else in Perth.

Thanks Bob, would really appreciate a look at your system. Have sent PM

Here is a good example of why it is important to change to 6" pipe. I have the same saw as the Grizzly(Laguna Platinum) but with a 6" outlet and after a months work it just has a sprinkling of dust in the bottom the cabinet. This was found on Jays custom creations website.

I used to clean out the dust from time to time on the inside of the cabinet but after realizing that it never gets any higher than the level in this picture I just leave it alone now.

Comparing similar builds, the prices are closer

Carbatec unit
https://www.carbatec.com.au/dust-con...e-ct-003vb-1ph

Timbecon unit

https://www.timbecon.com.au/extracti...dust-extractor

Ive been seriously looking at the 2hp Timbecon unit but with a pleated filter (with the similar build to the 3hp unit) due to the limited space I have.

Originally Posted by safari

Here is a good example of why it is important to change to 6" pipe. I have the same saw as the Grizzly(Laguna Platinum) but with a 6" outlet and after a months work it just has a sprinkling of dust in the bottom the cabinet. This was found on Jays custom creations website.

[emoji33]

That looks like a fire waiting to happen!

Originally Posted by BobL

If you want to come a see how I set up my DC, modified all my machines etc you are welcome to come and take a look.
Same offer goes for anyone else in Perth.

Thank you Bob for such a generous offer

Originally Posted by ian

Thank you Bob for such a generous offer

I like to think that all that taxpayer funded expertise I acquired whilst working continues to goes into something useful.

Originally Posted by safari

Here is a good example of why it is important to change to 6" pipe. I have the same saw as the Grizzly(Laguna Platinum) but with a 6" outlet and after a months work it just has a sprinkling of dust in the bottom the cabinet. This was found on Jays custom creations website.

I used to clean out the dust from time to time on the inside of the cabinet but after realizing that it never gets any higher than the level in this picture I just leave it alone now.

I'd be surprised if a huge part of the problem with the saw pictured wasn't the lack of effective crossflow in the cabinet, ie. there's no air inlet in to the cabinet other than through the blade slot and any other minor gaps. As BobL has indicated the DC can't suck air in if you're not introducing any in to the cabinet. Even with that crummy 4" flex you would need the equivalent of a 5" port in the cabinet to generate the necessary airflow.

Originally Posted by aldav

I'd be surprised if a huge part of the problem with the saw pictured wasn't the lack of effective crossflow in the cabinet, ie. there's no air inlet in to the cabinet other than through the blade slot any any other minor gaps. As BobL has indicated the DC can't suck air in if you're not introducing any in to the cabinet. Even with that crummy 4" flex you would need the equivalent of a 5" port in the cabinet to generate the necessary airflow.

+1. Even with a 6" pipe if there's no air going in, there won't be much coming out.

I've seen a similar thing at the mens shed.
Lots of blokes making a few small cuts, blokes too lazy to get the DC and hook it up to the cabinet, when challenged they say "I'm only doing a few cuts"m but it soon adds up
Open up the cabinet and it's choked down so hard there's no flow.

Thanks to everyone who responded to this thread and particularly to Bob L for the opportunity to see how it's done. Some really great ideas that helped to clarify in my mind what I needed to do to manage the dust issue.
I settled on the 2 HP industrial DC from Timbecon, the inlet port was on the base of the machine but with a bit of work and a lot of swearing I managed to turn the motor and fan assembly over and now have the port on the top of the machine where I can run the 6" pipe up and over to the outside of the shed. From there I plan to run pipes along the back wall of the shed and cut ports in the shed wall above the level of the bench so that all of the bulky pipes are out of the work area (as much as possible). Will post some pics when the work starts



IMG20161108115301.jpg

I would like to add something here. Most of us rightly or wrongly look at the wrong end of the problem as regards costs and looking at it differently might help. The ducting and installation cost is fixed no matter what the machine unless the machine demands a duct bigger than 150mm and 150mm is what most use and the installation will be the same for all dust extractors within reason. That leaves the costs of the DE itself and some are not much cheaper than a real cyclone and in the great big scheme of things the cyclone becomes better value for money. We all have our budget limitations of course but looking at it that way separates the two costs.

Hi Dave,
Can I ask if you flipped the motor over and left the rest of the unit in the same orientation, or if you lifted the whole lot off the support posts and turned it upside down ?
The reason I ask is that I am considering a similar dusty,and I think the part that holds the bags can only be orientated one way due to the cone that sits inside it .
Look forward to seeing the pics of your ducting set up.
Cheers,