Thread: Almost there!! Key points and a couple of questions

I am glad you had a look at BiLL's site. makes you think??? It sounds like you got the info off his site that you needed to know.

As you mention if you want to use the unit without bags, you have at least two options, use a cyclone.( which can give fantastic seperation) or have a look at the Phil THIEN web site( thien baffle plate seperator)
There is no shortage of information on various forums on the net on people building both. However I have yet to come across data that shows the differences between the 2 concepts.( eg: efficiency etc) clearly the cyclone is more difficult to make. Having made a number of the smaller ones, they are not impossible.

While you are looking on the net have a look at the Grizzly tools site, heaps of info on dust collectors.( relevant info, considering most come from Taiwan etc) just allow for the fact that USA generally run on 60hz and so the motor run faster than here in Aust.(output figures etc may vary)

Any 'homework' you do first, I believe, is worth the effort.

Greetings
Has nobody have an opinion on the second stage idea i put foreward?
I know there are a few of you out there with/or have had similar systems.
I like the idea of getting most of the bigger stuff and some dust before it gets to the blower.

Skippy

I've just such a separator - a 44gal drum - in the line and I wouldn't be without it. As you say, it disposes of the large particulates before they go through the impeller. It makes for less wear 'n tear and it's quieter.

It does reduce the overall "suck value" a wee tad, but that's mainly because I haven't made mine 100% air-tight and it's not such a large loss that it makes any obvious difference at the business ends... replacing my gates with better-than-carbatec-ones would make more difference than getting fussy about the seal.

I wouldn't run the DC itself without the bag/filter though. Depending on how efficient your separator build is, some will get through. Usually only the very fine dust, but once the drum fills to near capacity all sorts of stuff gets by. That's how I tell when it's time to empty mine; 'cos I can see larger dust collecting in the DC bag.

Without the bag there, a BIG mess is bound to happen sooner or later.

A 2nd stage 44gal drum is the way to go, also housing it externally to the shed. After putting up with the fine dust that escapes from the needlefelt bag with having the dusty inside the shed, I eventually moved it outside and it was a massive improvement.

One thing I did when I relocated the dusty and 2nd stage drum was to ditch both the 4" flexi hose and the wye that comes straight off the dusty.

A learned bloke above pointed out, the wye was creating a lot of turbulance or something like that, anyway it was reducing the effectiveness of the dusty. And instead I ran 5" flexi hose from the dusty to the 2nd stage drum. I found, although I have nothing scientifically to confirm it, the 5" hose significantly improved suction. I also ran 5" hose from the drum where it connected to the plumbing inside. On the inside of the shed, all the plumbing is 4" (cost of 5" + is a major investment and one that I cannot afford)

My thread might help out.

https://www.woodworkforums.com/showth...ty+shed&page=3

Hi Skip,
My thoughts...
You want the duct runs as short as possible

On the machines that produce large chips bigger is better than smaller as long as the pipe/hose is the same size or larger but not too much larger as you dont want the air speed to be too slow.... causes the chips to fall out of the airstream and settle on the bottom of the pipe/hose, also simillar thing with vertical rising pipework, chips won't go up, unless your machines r large industrial with fast feed rates 4 to 5" port and hose size should be fine, but keep the hose length to a minimum or go straight to pipe, I like to see the chips moving (tells me that I don't have a blockage) so I like a bit of hose out of the machine, if u r gonna do any hood mods to ur machine consider that the 800 cfm has to get into the machine for it to get out of the machine, on my carba tec 15" thicky I removed a piece of foam on the upstream side of the cutter block to allow air in, also reduces noise

A 6" main line yep but watch the air speed, a wind speed meter from dick smith is good for checking this, and from this you can then calculate an actual cfm value. Know any sailboat people? my 8" main line borders on being too big specially when I have 10m of 4" hose hanging off the end of it, this I know is not good but I dont want to cut it yet

A separator b4 the cyclone...umm I prolly wouldn't bother, not saying it wouldn't work but could be considered just another restriction?
If I was to go this way this is why I would be considering a separator...
My fan has to be in the dirty airstream but I don't want it constantly hit by chips, so separator b4 fan
I could probably then design a smaller cyclone to remove the finer dust, but my fan would have to be larger diameter to deal with the higher restrictions
I prolly wouldn't bother

If u can get away without anything on the outlet yep, it's one less restriction, that's how mine is and it's outside, I do have a muffler on it, that is also a restriction

A few pics of my homemade effort, the last one is an example of the large pieces/chips that it will pick up off the floor using the 4" hose due to a high enuff velocity but still not high enuff to carry them up the vertical section of hose, if they do get into the 8" main line they end up at the corner at the bottom of the vertical section just b4 the cyclone, bit of a bummer but is a temporary setup atm so...

Peter

Who makes and Where do i get good gates from?? Brand names would be good, so i can at least sound as if i know what i am on about when i go and ask for em somewhere.

Thanks Waldo, all good points here for me.
Liked your thread as well!!!

Skippy

G'Day PJT
I have already read your thread with great interest. I am pleased you attached some more snaps as i clears up a couple of things for me. I gotta say mate that is one seriously built cyclone !! As for what you call chips, i would almost call em back logs for the fire.
The thing is i am not doing the cyclone thing "Yet" so i figured the 2nd stage would be the go for protecting the blades a bit, plus reduce the loss of suck caused by having the bags on. This way i leave the bag off, and collect 99% of the chps and dust in the seperator. The rest of the fine dust would be let loose to the atmosphere. (The units will be outside the shed)
We are a far way from neighbours and the house is 40 metres away so i dont see any probs upsetting anyone.
I am aware, as pointed out in this thread, that i will forget to check the drum and will one day find one unholy mess around the dust extractor unit. But i am willing to face this mess WHEN it happens.

Skippy

Thanx for the comments,
When I wrote most of that blurb I was thinking more along the line of my setup where the fan is downstream of the dirty air (as long as the bin/cone isn't full) then it will spit a stream of stuff out

With something like Waldo's setup a separator is ideal b4 the fan, there's an article in issue 134 August 2007 of Aust Woodworker detailing the making of a separator without too much expense either

With the fine dust It will pay too keep an eye on it to see how far it goes, not that u will actually see where it goes, you don't want to be sending dust over to the nieghbors, it is best to keep the nieghbors happy, I used to live in Gladstone overlooking the port and the dust from the coal loading terminal which was 2km away, I would still get black dust settling on the window sills

There was a thread started a while back, something to do with controlling the fine dust by methods other than filters/bags, the idea was to bubble the airstream thru water thus trapping the fine particles, not sure how it ended up in the finish A few others thought that a water spray might work, some debate as to how effective this was gonna be, some physics about particle size, water droplet size, entrapment blah blah...also there was an article on a cyclone in one of the woodworking mags about a bloke who sprays water into his cyclone outlet, he seemed to think it worked! I do do something like this at times and I think it helps I just put the hose end on a fine spray into the muffler near the bottom, I only do this if I am doing something really dusty, elecrostatic precipotation ( I think it's called) is supposed to be good for dust control, might do a google and see what I can find out

Let us know how urs goes and there must be pics

Peter

http://www.baltec.net.au/ looks a bit interesting no idea if they do a small low cost one I will send them an email

Hhahaha definitelty will be pics when i eventually get around to setting it all up.