Homemade dust extraction - my thoughts so far.

[Monkey Mark]

I'm a hobbyist, and one on a very tight budget for that matter. I also like the idea of recycling/up-cycling and generally tinkering (I prefer to make something than buy it where possible).

For that reason I am, still, looking into making my own dust/chip extraction system and thought I'd put my musings into text. Maybe bouncing some ideas around may help myself and others.


Current situation:
At the moment I use a simple pneumatic vacuum cleaner for my extraction. It seems to do pretty well but struggles when I use my bench top planer and the noise, although not as loud as a conventional vacuum, can still become annoying after a while. It's also pretty old and it was second hand so I have no idea how long it will last me.
I've not yet added a cyclonic separator but whatever I do that will be one of the definite additions.

Environment:
My "workshop" is a single garage. It is also used for storing general DIY tools, my kids automotive tools & bikes and general crap which I'm slowly sifting through and disposing of - especially when the wife isn't looking :mrgreen:
It also has the tumble dryer in there and dust has been know to find its way through that.

Thoughts so far:
My garage is only small but that got me thinking that's a good and bad thing. Bad because I'm limited for space which is why I have not gone the usual root and bought an off the shelf dust/chip extractor. They can be quite big and I already struggle as it is. (Though if I got one cheap and woodchips I'd use that until I figured something out).
But good too as that means whatever system I use it won't have to be portable as all the machines will be in pretty close proximity to start with. The garage has a pitched roof, so there is the option of using some of the so far rarely used space up there.

I originally thought of using car radiator fans. They can be had cheap, run quiet and take little power. They could be doubled or trippled up in an enclosure for greater air flow.
This idea was quickly kicked to the curb though. After a little research I found out that although they can move quite a bit of air, they are no good when it comes to creating pressure. Whats more, when adding multiples in a single enclosure, the enclosure has to be "tuned" otherwise the internal buffeting between the fans can actually decrease the effectiveness to below that of one fan. So, car fans are out of the question. Though I may use one for a simple dust filter at some point.

I could look into making my own squirrel cage/centrifugal style fan. This could be effective and cheap however I don't yet think I have the tools or more importantly the skills required to make one effectively.

I could use pre-made centrifugal fans, perhaps from an industrial machine. I do have one from a warm air heating system but I don't this this will be powerful enough. Second hand ones regularly come up on auction sites but they are often so expensive, even second hand, it defeats the whole idea. They seem to be in abundance over in the States as they are in many household furnaces, but not so common over here.
We do have one at work but considering it stands about 5 feet tall and is powered by a rather large three phase motor it may be slightly overkill :roll:

My current thinking is that of using the likes of a blower from a bouncy castle.
I have seen one video of an Australian guy using one as an extractor but that's been the only one.
I don't yet know how much air they are capable of moving or how good they would be at creating pressure, but I think they must be able to produce a reasonable amount of pressure otherwise I would expect the back pressure to stall or bypass the fan when the fat kid gets on. (Only joking about the fat kid of course )
They could be doubled up, allowing for a Low and High setting and mounted in the roof space out of the way,
I often see them cheap locally and a lot of them seem pretty generic so getting a matching pair should be easy enough.

So, for this I now need to find out the following; How much air do they move? How do they cope with pressure? How noisy are they? What would the effect be of doubling them up? And most importantly, is the air and therefore the dust/chips drawn through the fan going to cause problems with the vanes?

Well, putting this into text has helped me organize my normally scattered thought process to some degree.
Any thoughts are more than welcome.

 

[LancsRick]

Ok, I'll jump in with a lot of what I suspect will be repeated messages...

Firstly, read up on HPLV vs HVLP (this will tell you a lot, I know because I've been through the same journey in the last few months). This is why your hoover isn't a good choice for the planer etc.

Secondly, you say you can pick up the blowers cheap. How cheap? Cheap enough that by the time you've made an enclosure and bag and filter (to <1micron) you're better off with that? I'd fork out the cash and buy a proper extractor.

If I sound forthright it's because I've recently been through the same line of thought, bitten the bullet, and seen the difference it's made in my workshop. I would really encourage you to get something like the Axminster basic machines and relax .

 

[sunnybob]

I dont think you will save anything by cobbling something together. You wont save money because you will never be happy and just keep adding to it. You definitely wont save time.
And while youre messing around making it, you wont save your lungs either.
While youre buying the extractor, make sure it runs through a cyclone. That is an amazing piece of kit.

 

[sploo]

The woodgears.ca site has a number of home made blowers and extractors, and may be a good place to start. However, I'd probably advise against trying to make your own - for a start, you need to think about what happens when a chunk of material hits the fan in your homemade blower (hint: if not well engineered - messy, and potentially dangerous for anyone close).

At low pressure, air tends to not compress well, so trying to extract from a machine with a small extraction outlet will kill the airflow. However, to capture dust on large machines you want significant air flow (both volume and linear speed). This ideally means a high pressure (low volume) vac for handheld machines, and a high volume (low pressure) impeller based extractor for fixed machinery.

The impeller based extractors aren't exactly quiet, but it's usually a low hum rather than the wail of a cheap vac.

If it's of any use, this was my solution: http://spikyfish.com/DustExtraction/

BTW A cyclonic separator is a great addition, but they do rob you of airflow, so you really need to start with a very powerful impeller in order to still have enough to capture dust at source.

 

[dzj]

Perhaps if you bought a mobile unit like this one:
https://www.bodyshop-tools-supplies.co. ... p?id=12892

and then made the ducting, cyclone and filters by yourself.

 

[sunnybob]

Thats an interesting little unit. Wonder how much noise it makes though? I had to build a noise cancelling cabinet for my collector. the whine was very hard on the ears.

 

[sploo]

Thats an interesting little unit. Wonder how much noise it makes though? I had to build a noise cancelling cabinet for my collector. the whine was very hard on the ears.

It should be deeper than a vac, but none of these things will be exactly quiet I'm afraid.

If you could add a suitable cyclone in front of it (check out Bill Pentz's site for designs) and drag it to your machine (i.e. minimum ducting and hose) then it might be OK. If possible, ejecting the exhaust outside would be a good idea too; with the cyclone there should be almost zero visible dust, and it means you don't need to worry about the cost or (capture and airflow) efficiency of filters.

 

[Monkey Mark]

I'll take a look on the woodgears site.

@ LancRik, I understand about biting the bullet and just getting something, but I simply cant. At the moment even £100 would be a stretch hence why I'm looking for alternatives. I'll upgrade in the future when money isn't quite so tight.

As for the bouncy castle blowers, the smaller ones usually sell for £15. Having difficulty finding out their cfm but think it's in the region of 300cfm each.

Also looking for single phase motors, preferably 3hp + if I go down the route of building my own but there doesn't seem to be too many come up second hand.

 

[sunnybob]

Look in your local yellow pages for motor rewind engineers, they will have spare motors of all sizes.

 

[sploo]

I'll take a look on the woodgears site.

@ LancRik, I understand about biting the bullet and just getting something, but I simply cant. At the moment even £100 would be a stretch hence why I'm looking for alternatives. I'll upgrade in the future when money isn't quite so tight.

As for the bouncy castle blowers, the smaller ones usually sell for £15. Having difficulty finding out their cfm but think it's in the region of 300cfm each.

Also looking for single phase motors, preferably 3hp + if I go down the route of building my own but there doesn't seem to be too many come up second hand.

Remember that if you're getting up to 3hp then you might need to install a 16amp line, as the inrush current on some motors means they'll pop a 13amp fuse like a ripe tomato.

I'd suggest also taking a look at Bill Pentz's site. There's a lot of information there (it can be heavy going) but it gives some good detail about low vs high pressure systems, linear (feet per minute) requirements for capture, ducting sizes, issues with flex hoses etc. A bit of reading could save you a lot of time and money.

Unless you were very lucky in scoring second hand items, I fear £100 all-in for something that's useful may be optimistic. By way of comparison, the motor+impeller I'm using (part of a Fox F50-843) claims somewhere in the region of 2300cfm (and it's just adequate with ducting); if that makes the problem clear vs a 300cfm bouncy castle blower. The bouncy castle blower won't have a material handling impeller either, so would need to be downstream of a cyclone, or protected with a wire mesh.

What machines are you trying to extract from (large table saw, bandsaw, router table etc.)?

 

[Roughcut]

Save your pennies and buy a proper manufactured dust extractor (new or used).
There are portable vacuum extractors which are suitable for 100mm outlet machines and power tool use also (Numatic for example) which do not take up any more floor space than a vacuum cleaner.
Ideal for a hobbyist with limited space in my opinion.

 

[Claymore]

I use a cyclone linked to a big shop vac for most machines, also have made my own airfilter units (one for my smaller room and another for my big room) and one of the things that made a massive difference to the whole building was 6 ten inch bathroom extractor fans that basically suck air and dust out through the walls and what a difference they have made. I got them all for £20 at a bootsale and local builder cut the holes in the workshop walls in exchange for my old table saw ok they do suck the heat out but in the warmer weather it will be great (i put them one for one hour after I close the workshop and there is no dust floating around)
I am only a hobbyist but do spend lots of hours in there so need to make it as healthy as possible BUT like most hobbyists have to try and keep costs down and I basically fund all my tool spending and workshop mods by making items and when they sell I have been investing in better quality kit.
I spent decades carving dental plaster and resins for a living with NO dust extraction or masks and guess my lungs are already iffy so anything that enables me to carry on working in my workshop is a must.

 

[siggy_7]

I think if you have a suitable motor (induction motor of between 1-3hp, 3000rpm) already for free (i.e. knackered tool) then making a blower can be a nice little project and potentially save you a few quid. For your situation however I would look to buying a centrifugal blower and then putting the rest of the system together. Suitable extractors tend to come up quite regularly second hand from people upgrading, or they aren't all that expensive to buy new. You can buy a compact unit from Axminster for £130 that does away with the collection bag, which if you are building a cyclone will be redundant anyway. That's probably the route I would take.

 

[Monkey Mark]

Hadn't thought about this for a while until today, when i was given a turbo dryer.

Still won't be powerful enough, but it's got me thinking again.

 

[morturn]

I personally think that there is no such thing as a cheap dust extractor, and that a dust extractor should be the best piece of kit in your workshop.

When I first set up my workshop I bought a cheap dust extractor. Each time I switched it on, it seems to put as many small partials back into the air as it was taking out.

I then had a close friend who developed respiratory disease, not from woodworking I may add. Seeing how this guy suffered, and died, was enough to make me think, get a decent dust extraction setup. Or at least vent it outside

If you wish to try a little experiment, get a nose clip on your nose and a drinking straw to breathe through; walk up and down the stairs once.

 

[Monkey Mark]

I personally think that there is no such thing as a cheap dust extractor, and that a dust extractor should be the best piece of kit in your workshop.

When I first set up my workshop I bought a cheap dust extractor. Each time I switched it on, it seems to put as many small partials back into the air as it was taking out.

I then had a close friend who developed respiratory disease, not from woodworking I may add. Seeing how this guy suffered, and died, was enough to make me think, get a decent dust extraction setup. Or at least vent it outside

If you wish to try a little experiment, get a nose clip on your nose and a drinking straw to breathe through; walk up and down the stairs once.

I understand what you are saying and agree. However, not everyone is in the position to buy one straight off.
As i see it, something home built is better than nothing at all and just because it's home made/cheaper, doesn't mean it will be useless.

 

[Adam9453]

Hi, I applaud you for trying to come up with a DIY dust extractor.
If you ever get down this end of the country then I've got a sip 01453 1hp dust extractor I'd be happy to sell you for a very cheap price. Pm me if you're interested

 

[morturn]

I personally think that there is no such thing as a cheap dust extractor, and that a dust extractor should be the best piece of kit in your workshop.

When I first set up my workshop I bought a cheap dust extractor. Each time I switched it on, it seems to put as many small partials back into the air as it was taking out.

I then had a close friend who developed respiratory disease, not from woodworking I may add. Seeing how this guy suffered, and died, was enough to make me think, get a decent dust extraction setup. Or at least vent it outside

If you wish to try a little experiment, get a nose clip on your nose and a drinking straw to breathe through; walk up and down the stairs once.

I understand what you are saying and agree. However, not everyone is in the position to buy one straight off.
As i see it, something home built is better than nothing at all and just because it's home made/cheaper, doesn't mean it will be useless.

I don't recall using the word 'useless' and if it is a question of money, which I do understand, take a look at venting it outside.

 

[n0legs]

Hadn't thought about this for a while until today, when i was given a turbo dryer.

Still won't be powerful enough, but it's got me thinking again.

If it's the 2 speed model like mine, it will lift a 20 foot lounge carpet.
Might be very useful. Get the grey matter working :lol:

 

[Monkey Mark]

I personally think that there is no such thing as a cheap dust extractor, and that a dust extractor should be the best piece of kit in your workshop.

When I first set up my workshop I bought a cheap dust extractor. Each time I switched it on, it seems to put as many small partials back into the air as it was taking out.

I then had a close friend who developed respiratory disease, not from woodworking I may add. Seeing how this guy suffered, and died, was enough to make me think, get a decent dust extraction setup. Or at least vent it outside

If you wish to try a little experiment, get a nose clip on your nose and a drinking straw to breathe through; walk up and down the stairs once.

I understand what you are saying and agree. However, not everyone is in the position to buy one straight off.
As i see it, something home built is better than nothing at all and just because it's home made/cheaper, doesn't mean it will be useless.

I don't recall using the word 'useless' and if it is a question of money, which I do understand, take a look at venting it outside.

Apologies if that came across wrong, reading it back myself it does a little. I know that useless wasn't what you said, just trying to say something is better than nothing.