Thread: A coupe Q's about extraction for cnc, pleated filters.

Put the dust collector outside and build a housing around it with sound insulation in the walls. Do not panel the inside just put insulation batts in the walls and roof. Cool it with a baffled inlet and exhaust with a fan driving the air through the baffle. You could also pull it apart and build a Thien collector and exhaust through the bags which can then be installed outside. Useful links....

Thien collector..
YouTube - thien dust separator

Enclosed Cyclone with baffle..
ClearVue Cyclones, Dust Collection Cyclone
main_page=videos&zenid=vpc6rq3r2ijvc0dtdf1cf89oq0

Or build a Bill Pentz cyclone, it will separate down to small micron size, insulate it and exhaust straight to atmosphere, this is the best option of course. I like the dust shoe, that has possibilities for saws as well as routers.

Thanks Chris, the Thien seperator looks like a much quicker project than the cyclone so that could be the way to go with venting it outside.

I could pull my extractor apart reasonably easily, the only issue would be how it currently connects to the bags, it is a rectangular section. Not sure how I will join the rectangular to pipe.

Originally Posted by Mini

Put the dust collector outside and build a housing around it with sound insulation in the walls. Do not panel the inside just put insulation batts in the walls and roof.

Insulation batts will do very little to absorb sound or prevent sound transmission. To do this sheer mass is needed. Something like 32 mm chipboard or if $ are no object hardwood, or lead lined concrete is far more effective. Gyprock is better than insulation batts.

Cool it with a baffled inlet and exhaust with a fan driving the air through the baffle.

There should be no need to worry about cooling if an air exit for the enclosure itself is locate near the motor as the large amount of air that needs to escape from the enclosure will be enough to cool the motor. My enclosure just has small slits in the enclosure at the bottom and the main air escape gaps on the sides at the top. I have often had it operating continuously all day on hot perth summers days.

Thanks for your input as well Bob.

I think I need to move it inside, the wife will not be happy with an enclosure of it as it's right near the front door at the moment..

I suppose I could make one of the thien's to go straight on to the DC as it is and instead of having a top bag I just have the hose going out the door and along the house.

I guess I will need to move to plastic bags. As it will only be connected to the router I guess there will not be huge amounts created.

I suppose it can be one of the first projects for the CNC, make the dust collector for it

Thanks,
Jason

Originally Posted by metalnwood

Thanks for your input as well Bob.

I think I need to move it inside, the wife will not be happy with an enclosure of it as it's right near the front door at the moment..
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Yep can appreciate the domestic problems. I have my BS and thicknesser on the back veranda at the moment and using a standard 2HP DC with these the DC drops fine dust all over the washing lines (also on veranda) so I have to wipe down the lines after every use. My new shed should fix all this.

You can always make an enclosure inside your work area, just vent the enclosure to the outside and not back into work area.

Originally Posted by BobL

Insulation batts will do very little to absorb sound or prevent sound transmission. To do this sheer mass is needed. Something like 32 mm chipboard or if $ are no object hardwood, or lead lined concrete is far more effective. Gyprock is better than insulation batts.


There should be no need to worry about cooling if an air exit for the enclosure itself is locate near the motor as the large amount of air that needs to escape from the enclosure will be enough to cool the motor. My enclosure just has small slits in the enclosure at the bottom and the main air escape gaps on the sides at the top. I have often had it operating continuously all day on hot perth summers days.

Why would air need to escape from the enclosure? So you dump the dirty exhaust in the enclosure??

The aim of not panelling the insides is to stop the noise reflecting off the panel surface.

Originally Posted by Mini

Why would air need to escape from the enclosure? So you dump the dirty exhaust in the enclosure??

The air has to go somewhere otherwise the back pressure on the DC will stop it working. To stop the sound escaping the air escape opening in the enclosure should be kept as small as possible but the area of the enclosure opening should be at least ~x4 the cross sectional area of the input pipe to the DC.

The aim of not panelling the insides is to stop the noise reflecting off the panel surface.

It doesn't matter if it reflects as long as it stays inside the enclosure. Contrary to popular understanding it does not build up and leak out. It will eventually be absorbed, it just takes a few more refections to do it. The critical thing is reducing sound transmitted to the outside. A lightweight material like sponge rubber reduces sound reflection but still transmits some sound. Anechoic chambers are made of thick concrete to stop transmittance between the inside and outside for that reason. The sponge rubber inside just reduces reflections of any inside noise .

Certainly not the way I would do it or the way I have seen it done, exhausting the air that is. Why fill up the enclosure with exhausted dust, that seems self defeating to me as when you open it up dust is present and you are back to having to deal with it. perhaps I have missed something?

Originally Posted by BobL

Yep can appreciate the domestic problems. I have my BS and thicknesser on the back veranda at the moment and using a standard 2HP DC with these the DC drops fine dust all over the washing lines (also on veranda) so I have to wipe down the lines after every use. My new shed should fix all this.

You can always make an enclosure inside your work area, just vent the enclosure to the outside and not back into work area.

I think you need a system with better separation Bob not a new shed. A new shed won't suddenly produce better separation but I guess if it doesn't dump all the exhaust on the line then the missus is a happy camper and marital bliss can never be underestimated.

Originally Posted by Mini

I think you need a system with better separation Bob not a new shed. A new shed won't suddenly produce better separation but I guess if it doesn't dump all the exhaust on the line then the missus is a happy camper and marital bliss can never be underestimated.

Yeah - I know I should get a cyclone. I feel like the kids I teach - if they say something often enough they think it might happen

My Shed DC is not the one I use with the machines on the back veranda under the washing line. The DC for the shed is on the other side of the old part of the shed on the RHS of this photo.

The back veranda and washing line is behind me while I was taking the above photo.

My new DC has 5 micron bags and the old one has 30 micro bags. The new one is going outside in the same place as the old one. This was my old enclosure - I could just squeeze a 2HP unit in there.

However, I will need to rebuild the enclosure as it is too small and I will need better soundproofing for the 3HP DC.

Originally Posted by Mini

Certainly not the way I would do it or the way I have seen it done, exhausting the air that is. Why fill up the enclosure with exhausted dust, that seems self defeating to me as when you open it up dust is present and you are back to having to deal with it. perhaps I have missed something?

I am just showing one way of doing it if someone cannot have an outside enclosure. Several people on here have done this and someone (can't remember who) did an excellent job on theirs. I have also seen this method used by people on overseas websites - even if it is just to reduce DC noise in the shed.

Of course one avoids opening the enclosure while making dust and preferably even when the DC is running . But once the dust making activity and preferably after running the DC for a few minutes there after, the amount of air borne dust in the enclosure is not high and will not swamp the shed if the enclosure is opened. So what if some leaks out, Start up the DC open all vents and run it for 15-20 till it clears the shed again.

The other thing some people have done to reduce dusty air inside the enclosure leaking out into the shed while emptying bags etc is to put a small extractor fan direct to the outside. This is only run while changing bags etc.

Originally Posted by BobL

Insulation batts will do very little to absorb sound or prevent sound transmission. To do this sheer mass is needed. Something like 32 mm chipboard or if $ are no object hardwood, or lead lined concrete is far more effective. Gyprock is better than insulation batts.

My understanding is that a combination of a soft mat'l (insulation/foam) and a hard dense reflective surface (chipboard/plaster/masonite/sheet metal) is a good solution to sound deadening, the soft mat'l is backed up by the hard surface, the soft matl absorbs and spreads the pressure wave within the soft mat'l, any sound that penetrates thru the soft mat'l is then reflected off the hard surface back into the soft mat'l and futher absorbed in the soft in a continuous cycle, we see this in many instances in industry, mufflers, hearing testing booths, sound proofing on machinery, from memory I think there might be something on mufflers for DC's on Bill's site, or I might have seen it somewhere else blame google, the frequency of the noise has to be considered and how to dampen it, as I understand it high frequency noise (typically from woodworking machines)is easier to dampen than low frequency, this is why we hear the thump thump thump of the nieghbors stereo but can't hear the words, mass is the way here, I have some sound insulation that is 25mm thick foam backed with lead impregnated rubber about 5mm thick, very good, very expensive and heavy, picking up the roll is like picking up a dead body umm not that I have done that, all floppy and difficult.

The exhaust on my DC I insulated the bend with sound insulation foam and sheet metal, I also added a muffler, it was a laundry chute that just happened to be the right size, 50mm thick sound absorbing foam was glued inside on each side of chute, it went from a whhhhhhiiiiiinne to a purrrrrrr that I cant hear unless I am right next to it and stick my ear next to the outlet.

dust collector.jpg


Pete

Guys, how about this.. Most simple of all.

I disconnect the blower from the bags and mount the blower inside and use 6" hose to connect to the bags outside.

I don't know for sure but if the majority of the noise comes from the blower unit then I have done my job putting it inside and kept the dust outside.

I will then put a pleated filter on but my question is how often do I need to clean it with only router dust, any ideas?

I will post in the CNC forum as well as these guys will be making lots of the same sort of dust.

Thanks,
Jason

Originally Posted by metalnwood

Guys, how about this.. Most simple of all.

I disconnect the blower from the bags and mount the blower inside and use 6" hose to connect to the bags outside.

I don't know for sure but if the majority of the noise comes from the blower unit then I have done my job putting it inside and kept the dust outside.

Most of the noise will be the blower and this can't be put into a noise reducing box without some cooling and then you are back to square one. It's also better to have the blower as close as possible to the filtering media.

I will then put a pleated filter on but my question is how often do I need to clean it with only router dust, any ideas?

Probably not that much