View Full Version : making a dust extractor

Alistair Hosie
05-06-2003, 03:43 AM
Has anyone ever made a dust extractor for a woodshop etc.I have plans to make a cyclone type dust extractor using an existing extractor motor and making the cyclone type housing, but as I have a very heavy duty motor on a stand almost new I am tempted to make it all from scratch i e impeller and unit myself.I am thinking of making up a plate and welding on fins marking out first with a dividing chuck so as to keep the fins all regularly spaced to avoid vibration.What problems am I likely to meet? anyone ever done this let me know, as I am greatly in need of a shop system as I have all small units fitted to each machine at the moment.Or should I build a unit with two of the existing vacuum heads I am currently using as these are very powerful at two one horse power motors each vacuum machine . I figure two of these I E four one horse power motors in all, at the top should be powerful enough to suck up anything. regards Alistair

05-06-2003, 05:37 AM
If you fabricate the impeller, you might try varying the spacing of the fins slightly for 180 degrees, then use the same varied spacing for the other 180. That way, the impeller will stay balanced, and the possible howling will be reduced. I don't know if that would be a problem for you, but it's a way to reduce noise. I have a fan that's made with unequally spaced blades, for that reason, to reduce noise. Just a thought, noise and balance are the major problem areas I can think of, another is matching the speed of the motor with the impeller diameter for best performance without overloading the motor, or underutilizing it.

Alistair Hosie
05-06-2003, 05:57 AM
Darryl good man. I never thought of that. Alistair

Paul Gauthier
05-06-2003, 06:53 AM
I was going to make one but then my son-in-law gave me new 3hp 4 bag unit. I was going to look into using the impellor from a 2 stage snow blower as the fan coupled to a 5 hp electric motor. Was going to use a 55 gal. barrel for the cyclone, would only have to fabricate the cone section. I may do it anyway I have some woodworking friends who could use it.

Paul G.

05-06-2003, 07:02 AM
we use bag houses in the carpet mills to clean the exhaust of the fans, gravity seperates to clean out the bottom into a dumpster. You do know it is explosive in the right mix?
A dust initiator can increase the explosive reaction of any type of dust, grain, wood, etc. Lots of flattened buildings for apparently no reason. And the blue smoke off a router.. yep.. we never think about it till it goes boom.

Me scottish friend, do you know of a pattern copier? I used to see them for copying gunstocks in wood. (router)

read my post, casting. I am thinking of carving Sand. That is something you should be good at with your woodworking experience.

I seen a excellent working vacuum made with cones, the intake was in the middle and exited out the ends. I ended up with a bunch of large vacuum motors-pumps, but have sold them all.
Be careful it is not something that self destructs from centrifugal force. I'd weld-glue and rivet the blades.

http://www.copycarver.com/building.htm Check out this site..

They use a drier blower motor and fan here. For a dust collector. cheap.. pretty cool site too..

[This message has been edited by ibewgypsie (edited 05-06-2003).]

05-06-2003, 12:17 PM
Lindsy Publications have a good book on it that I followed to make one.


05-06-2003, 02:30 PM
Hello Alistair:
We had a similar discussion about dust collection last September when I asked about PVC vs Metal dust collection piping. Among the spirited discussion, were a couple of links about dust collectors--home built and purchased that were very good. One was a "Wood Magazine" link that showed their $9.95 plan set for building a dust collector. If you click on search, search for posts by me. You'll find it listed as "PVC versus metal pipe for dust collection".(that may not be the exact title, but oyu will recognize it.) Good luck--Mike.

05-06-2003, 07:34 PM
A friend works in a processing plant of some kind, I'm not sure what, but they run a dust collection system which sucks the dust upwards against a filter. When stopped, the dust falls into a waiting bin below, with a bit of help from a big stick ( banging on the framework). There was still lots of very fine dust leaving the exhaust, which apparently affected a plastics plant in the same complex. My suggestion was to use an electrostatic module before the final exit to 'attract out' the remainder. The response was a good bit of laughter, with some eye-rolling, and the thought, 'that's all we need, an explosion'. My next idea wasn't as funny, but I'm sure it has it's own problems, groundwater pollution, perhaps- I suggested a water misting system. My own system is just a fan mounted at the top of a large tube, which has most of the tube cut away, leaving just support pillars. I wrap a filter blanket around it, and shake the dust into a box when it looks loaded. It takes up about a square foot of floor space, and stands 4 ft high, doubles as an auxilliary ac outlet, so I can plug the router or sanders into it. My fan is not powerful enough, though it does clear the air in the shop after a short time.

05-06-2003, 10:39 PM
Alistair: I think you are thinking of too large a system. We used to make a "rice dryer". Had a 5 hp 3 phase motor. The impeller was made of fabric belting. Four pieces I think, bolted to a hub that had 4 angle irons welded to the hub. the fabric bolted to the angles. The thing was self regulating- as the load increased the belts bent back and unloaded the motor. They would suck air through a grain bin full of rice.

Things to remember about a centrifugal fan are:1> The power needed varies as the CUBE of the speed. 2> its easy to overlaod the motor by blocking the OUTPUT hole. 3> you reduce the needed power by partially blocking the inlet hole.

We were pumping grain dust through the fans. The motors were totaly enclosed but not explosion proof, the fabric vanes were not going to spark. Static Balancing was done by trimming the vanes with a pocket knife. Course if anything had happened , they were always in the middle of field. Of course the better solution (and maybe cheaper in the long run) is to buy approved equipment.

The "bag room" and "cyclone" seperators work well in industrial use.

05-07-2003, 02:20 AM
www.leevalley.com (http://www.leevalley.com) has all the books and parts you need to build a high performance system even if you decide to use a 6HP shopvac to power it (Not the best solution, but it can work).

If you decide to get something from Lee Valley email me or call me - maybe I can help on the shipping.

Alistair Hosie
05-07-2003, 07:15 PM
The reason I am thinking of changing my current system is because every time I make something I end up cleaning up for hours afterwards and its getting to the stage I am reluctant to start, knowing that all this work will have to be done at the end.I have a friend who was in the same situation but he recently installed a Felder system with complete ducting etc ,and he now says that he has virually no dust atall when doing things this sounds highly suspicious to me although if he says it it must be true just hard to imagine thats all has anyone else had this experience regards Alistair

05-07-2003, 07:34 PM
Me too alistair. I was looking for a young man to clean up around my shop and earn a little with me. Finding one of the rascals that don't have the boom boom stereo and the saggy pants is getting hard. Getting a helper that won't come back and take all my hard earned tools to the pawn shop is another.
I probably will settle for a vacuum system.
Let me know what you finalize on, I am looking too.

05-08-2003, 12:08 AM
Allister,I too am adicted to woodworking,I haven't built any blowers,but I have installed a few for friends and industry,One thing to remember is if you don't use metal pipe be sure and run a ground wire to remove static.I also recomend to my Industrial clients an alternative to cyclones,I prefer to use the blower to push air past a siphon made from a long radius bend pipe and a straight section,this eliminates anything going trough a impeller,including dust,it will work well for you so long as you use a 1200cfm or greater unit with at least 2.0"static pressure.By the way what kind of things do you build?I do everthing from kitchen cabinets to sailboats.

05-08-2003, 12:40 AM

Alistair make Furniture, toys, tools, and teeth. The man is an animal in a kilt.

If I had a kilt I could do my best "Marylin Monroe" impression over floor ducts in the winter - please, no applause.... http://bbs.homeshopmachinist.net//eek.gif http://bbs.homeshopmachinist.net//tongue.gif http://bbs.homeshopmachinist.net//biggrin.gif

Alistair Hosie
05-08-2003, 03:12 AM
is that what Marylin was doing and all these years I thought she was suffering wit exess gas http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif Alistair I suppose it would work

Alistair Hosie
05-08-2003, 03:25 AM
Wierdscience I more or less attempt anything with wood if it can be done inc turning, which I enjoy immensly also,cabinetmaking, toys, my plan is mostly to design my own furniture as I see my shop as an art workshop as opposed to a wood shop per se and it is this element of designing things which are unusual and to my taste which intrigues me.I am foolish enough to attempt it.If I buy a book for example on dolls houses I always attempt whichever I fancy never mind what the book says about starting with model A etc ,and building your experience up with this before going to model x.
Ibew I agree theft is a problem I am terrified that the rouges will discover my shop and I will lose my sleep at nights you are wise to be cautious why not put a picture of yourself with that mask outside that would work it scared the hell out of me incidently I will write to you later about the casting buddy . Regards and thanks to all so far Alistair (the big artist with the little brush)

05-08-2003, 04:00 AM
Try this link for more info than you ever thought possible about cyclone dust collection in the home workshop:


If you have more questions, you might try looking in on the woodnet forums:


There's quite a few people there running dust collectors at various stages of home-brew....

05-08-2003, 11:26 PM
Gee,thanks Thrud,you in a kilt doing a Marilyn impersonation,now I won't be able to sleep tonight for all the night terrors http://bbs.homeshopmachinist.net//biggrin.gif Allister,I too love wood turning,the sad part is in the last two years I have built two wood lathes and have not had the time to turn anything http://bbs.homeshopmachinist.net//frown.gifIts like waving a ham sandwich in front of a starving man.I also look at the pictures and throw the book away,I like pictures,I wish this bbs had more pictures-well..not of certain people in kilts anyway http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif

05-08-2003, 11:45 PM
At least I was not planning on doing it "commando"...or was I? http://bbs.homeshopmachinist.net//eek.gif http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif

05-09-2003, 12:11 AM

[This message has been edited by wierdscience (edited 05-09-2003).]

05-09-2003, 12:12 AM
OMG!another visual!stop!..it burns!..it burns! http://bbs.homeshopmachinist.net//biggrin.gifOMG!"THE RETURN of BUTT CRACK-GUY"!

05-09-2003, 12:58 AM
HEY.. Alistair.. Geeze, did you figure out how the router copier worked on the page I listed?

Thrud, imitating marilyn, No... That was the most perfect female body I ever saw (marilyn) Drugs made her ugly in the end.. I think she was a embarrassment to the kennedys too.

[This message has been edited by ibewgypsie (edited 05-09-2003).]

05-10-2003, 01:35 AM
I was not trying to demean Norma Jean, and Ted has embarrased the family more than she ever could have. That would be Ted "outlaw ammo sales to citizens" Kennedy for you voters...

BTW, has everyone seen the new S&W .500 Magnum? I want two, they're small. http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//biggrin.gif http://bbs.homeshopmachinist.net//tongue.gif

Paul Gauthier
05-10-2003, 07:29 AM
I haven't seen one in the flesh yet but hope to at the Springfield, Ma gunshow at the end of this month. I don't know how much it weighs but hopefully it is less than that POS .50 AE Desert Eagle.

Do I want one?? You bet, but then I want one of everything.

Paul G.