Charnwood dust extractor

[RogerS]

Following on from a number of posts and comments I asked Charnwood whether a finer filter could be fitted, from their own range, to this extractor.

This is the reply I received from Charnwood which may be helpful to some of you.

There are no upgrades available for the W690.

The standard bag on the W691 is a cloth bag around 10 microns. You can upgrade to a 2 micron needle felt bag £44.00 You can also upgrade to a 0.5 micron cartridge filter £159.00

Our 2 micron filter is suitable for somebody mainly using timber and occasionaly MDF. If you are using either MDF continously or collecting from a sander then the cartridge filter is the ultimate step. Only professional users generaly buy the cartridge filter to use with one of our Trade rated machines, however it will also fit the DIY models.

 

[Barry Burgess]

Roger I am pleased that they admit that the felt bag filter will only get down to 2 micron. At that it will leak MDF dust. Their price for the .5 micro filter is expensive. I think I paid £59 + carriage on Ebay( I will find the details if you need one). The problem of fitting a filter(been there done that) is that a large amount of dust from the extractors goes to the top bag outlet and gets into the filter. I found that you would have to clean the filter at least one a month. What I resorted to do was to bang the outside of the filter with my hand and the dust would fall into the lower bag.
Barry

 

[davy_owen_88]

I couldn't find the cartridge filter on the Charnwood website, so either I'm blind and missed it or they were referring to a filter you could buy elsewhere.

Either way, for £159 that better be one massive filter, since for £61.50 you can get a .5 micron filter catridge from eBay with 20 m^2 of surface area: Ebay link

When I move to my new shop I think I'll be buying me a second hand 3HP extractor and either building or buying in a cyclone with 2 of those filters.

(I'm not copying you Barry honest... It just seems you've done the thinking for me)

 

[Pecker]

Hi guys, that filter on ebay. How does it work? do you put it in the top bag? does it sit on top of the machine, if so, how does it attach/hold itself on?

oh just to be picky, vat and postage makes it £69.75 :wink: -which is still a damn site cheaper than £159 though!


cheers all
mark

 

[Barry Burgess]

Mark this is how it works

 

[RogerS]

Barry..please can you post details of the filter. Thanks.

Has anyone tried the Dakota cyclone lids from Rutlands?

 

[Barry Burgess]

Roger Davy owen posted it above. Those are the ones I used.

 

[RogerS]

Oops...crossed post!

Has anyone tried the Dakota cyclone lid from Rutlands?

 

[Pecker]

Thanks barry, nice setup there. Can they be used on most Cheapo type bag extractors to improve them? how do you clean them?

cheers mark

 

[Barry Burgess]

Mark I have moved on from there.

What I did to clean the filter I banged the sides with my hand and most dropped through to the lower bag. I did this once a week. Now nearly all of the chips and dust(99%) remain in the cyclone so its less of a problem.
Barry

 

[gardenshed]

Barry's method of tapping the sides of the drum with the palm of your hands
is how the Scheppach extractors fitted with fine filters describe how to clean them. And it does work very well.

I have the Scheppach fine filter and you can also wash it out once in a while. I do mine every 3 months or so, I even use a jetwash to do it (but not on full power). especially if I have been machining a lot of MDF. But just tapping it once a week is usually sufficient.

I wouldn't use any extractor that couldn't filter down to 0.5 microns, the difference between 2 micron or 1 micron & then using 0.5 is amazing.

Barry's extractor is impressive, and I suspect that only a miniscule amount of dust gets to the filters.

 

[Pecker]

Are you sure you're not brewing hooch there? :lol: :lol: :lol:

Barry your setup looks incredible. How about a description of what all the components are? Or even better a complete rundown of how to build it. I'm sure I cannot be alone in thinking what an amazing setup you have and would love to make something similar.

How long did it take you to build it?

Kind regards
mark

 

[Barry Burgess]

Mark most of the construction is on the BB in various posts. The far right is my cheapie cyclone created from an Ikea flower pot and a 65 liter drum. In the middle at the top is the remaining impellor and 3HP motor from my original dust extrator. Below that is a baffle/silencer/muffler what ever you want to call it that takes about 10 DB from the noise created. On the left is the 40m2 .5 micro filter with a collection box at the bottom.

I started out by making a mini "cyclone" for a vacuum cleaner and attached it to my table saw. Then I bought a router table I built another one using the Dyson dual cyclone system. After that I visited the Bill Pentz site and that was the start of the trouble. Spent months searching for a 14" Jet impellor - it was only used in the USA. Took the Pentz design to many places to make it for me. Most would not quote and one started to make it but produced nothing after three months. The lowest quote was £600 and the highest was £1150 +VAT. Thought of buying the perspex one from the USA but freight killed the idea. Bought a second hand 3HP dust extractor on Ebay for £150 delivered. Descovered it was a dust creator - the rest is history.
Sorry for the boring details and hijacking the thread
Barry

 

[RogerS]

No hijack, Barry!

Did you play around with the Dakota cyclone lid from Rutlands as part of your research?

One question I'm curious about and that is ....why is the cyclone design better than many of the availalable dust extractors on the market at the moment (I'm thinking Schepach, CamVac, possibly Charnwood + 0.5 micron filter, etc)

 

[DaveL]

I have a home made cyclone as well.

The cyclone works by using centrifugal force to separate the dust out of the air, if the design is right most of the dust is dropped out the bottom of the cone. Only the finest of dust will still be in the exhaust air, that’s why you need the 0.5 micron filters but the amount of dust should be very small so the filters will not clog quickly.

The standard dust collector with the plastic bag on the bottom and the filter bag on the top relies on mechanically stopping the dust on the filter, most of the smaller dust < 100 micron hits the filter, the smallest <10 micron goes out the filter. With use the filter gets better due to it clogging at the expense of the air flow.

Fitting a 0.5 micron filter on a standard dust collector works but you need to clean the filters much more frequently.

The other advantage is the fan does not have all of the dust and off cuts pass through it, useful when your working on small things. I have retrieved things from the dust bin that I sucked up and they may be bumped due to going up the pipe but they are not smashed from going through the fan.

 

[Barry Burgess]

Roger As Dave said, the dust and chips are separated from the air. I also have an air ramp in the cyclone to aid the dust to start the cyclone motion.
What is critical is to get the dimensions right to aid this process. The ratio of the top chamber to the cone should be 1 to 1.6. The change of the input pipe from round to rectangular and the angle it goes into the chamber are important.

Dave I am getting no dust that I can see passing to the impellor or filters.

Roger most of the dust extractor let the fine dust out of the bags so the bottom cloth bag has to be replaced by plastic bag and the top bag has to filter to .5 micron. None of the bags will achieve that from all that I have seen. The other major problem is that the air needs a larger area to escape and the square footage of the bags is not large enough.

The Camvac appears to work on the principle of a dust separator bucket.
When I looked at it , it did not use 4" or larger hose which now occurs.
Rutlands did not have a cyclone when I looked.

 

[Pecker]

Barry, I presume you did eventually get the 14" impellor?

Dave, what did you use? Did you also use Bill Prentz's designs?

Appologies to the original poster, I know we have gone a tad off topic

Mark

 

[Barry Burgess]

No Mark I got a second hand extractor with a 13" metal impellor. Most of the new impellors are now plastic.
Barry

 

[RogerS]

No apologies needed, Mark. It's all fascinating stuff and I'm also amazed that no-one in the UK (EEC even?) makes a cyclone for woodworkers!

 

[DaveL]

Mark,

If you look hereyou can see the cyclone being finished, long post, lots of pictures.
The plans came from Wood magazine and the blower is only a 1HP unit from a Nutool dust collector, nice steel fan in it. The fan is not pulling the full 1HP from the motor, I ran some tests and even with no restrictions it does not max the motor out. It works OK, if I stumble on a bigger one for not much money I will upgrade.
If I was doing it again I would pop along to IKEA for the cone and work round that, Barry has a good solution there.
I have have been running without any filters, not good but better than the bag on the dust collector, I have bought 2 filters from the same firm on ebay as Barry. I want to put then into the roof space of the workshop, for a couple of reasons. It saves floor space, there is never enough room. I have also found that venting the air up high has heat benefit in the winter. I use a wood burner to heat the shop, the warmest place is in the roof space. When I run the cyclone it moves so much air from 3' or 4' up to 8'. that the warm air gets blown down and I get a much more even temperature.