Thread: Dust Collection - Machinery Connections

Good questions.

I only replyed so I can keep an eye on the thread.

Al

bitingmidge,

I'm glad you asked these questions. The same ones I was going to ask. I'm running 6" ducting and decided to try 4" to everything for a start. If I have to modify every machine for 6" connectors, I'll die of lung disease before I get it finished. I'll slowly convert to 6" where I can. I'll be making my own blast gates and they'll be 6".

Grunt

If I have to modify every machine for 6" connectors, I'll die of lung disease before I get it finished.

I know that feeling! I'm leaving the DC on wheels and the 4" connectors in place until it's all done...and at the rate I have been going that could be a long, long time.

I decided that NOTHING else will be started till it's all hooked up....so started woodturning classes, milled a bit of oregon and tuned the thicknesser on the weekend.....looks like that decision wasn't much chop!


Cheers,

P

Midge,
I've never seen 6" connections to machines anywhere. Even joineries and timber yards that have been running big thicknessers and 4 headers. Usually they've run a 5" or 6" main line and branched off with 4" lines. In the case of larger machines sometimes they run 2 x 4" lines. I believe that this is the way to go as 6" lines are pertty unweildy to connect to machines. Personally I only have a 2hp extractor that I move from machine to machine but eventually I'm going to have a larger extractor in an annexe to the shed with a 6" main line and 4" branches. I don't know that a bandsw really needs a pick up point above the table, and as you say, mounting it would be a headache. If anything a smaller vac type collector with its higher velocity would probably work better here.

Mick

Mick,
Thanks, I don't want to debate you at all here..my questions arose from comments on Bill P's site that specifically talk about the 6" upgrade to remove more of the super-fine particles, but I haven't seen anyone actually do it either!

I smiled when you said you only have a little 2HP unit, 'cos I thought I had a REALLY BIG 2HP unit!! Might be the next thing I upgrade!

Cheers,

P

Midge,
not trying to debate either , just adding my observations. Also thinking about the difficulties of actually finding a space on some machines where you could mount a 6" connector. Just wondering though what the theory is behind being able to remove more of the finer particles with a 6" connection. Surely if one or two 4" connections gave enough airflow to stop anything escaping then that would work equally well? :confused:
A lot of the places I've worked would horrify a lot of the keen dust collectors on this BB. On site: no dust collection or control at all. In workshops: individual DCs on machines, panel saws only connected underneath, no collection on bandsaws or drill presses or hand operations, sanding done outside. Every morning the first year apprentices empty out the DC bags, bins and sweep the floors. Because of the multiple bag type DCs inside and all the workstations without collection there was always a fine coating of dust everywhere (and often a thick layer of dust in many places :mad: ). Lunchroom was just a table in a corner of the workshop, often coated in dust also :eek:

Mick (coff coff hack hack)

midge

I ran 6" pvc right round my shed about 6 months ago and installed 5 gates at various points. I used T pieces for the gates and then purchased screw caps for all the T pieces/gates and then took flexible 4" hose and using a 4" connector cut a hole in one of the screw caps and placed the 4" pipe inside the cap. At the time I thought this was a great idea cause I could block off the unused gates and then run the 4" from the one I wanted. Problem is that over time I ahve gotten so sick of screwing and unscrewing the caps as I move round the shed that I probably only do it half the time. I also have slowed down with connections to each tool I have. As outlets for dust extraction seem to be a different size for each tool I own I am still yet to connect them all to the 4".

I

Intention here is 6" main line and 4" flex lines to equipment with reducers for those that do not have 4" outlets like the Triton router/table!!! I'm sure Bill's posts endorsed this approach. Sadly like others I still haven't completed the installation - guess the personal respirator and 2 2hp DC's along with opening the doors and windows of the garage seems more expedient at the moment. Mind you up here on the Tweed at this time of year it is sunny and a pleasant 24 degrees - freeze the walls off a bark humpy in VIC I dare say

From my perspective whereas I have fitted 4" ducting and take-offs with blast gates to each machine I have no problem with the removal from the Lathe,Combination unit, Bandsaw,Drumsander and a reducer for the Festo ROS.
For the extra fine airborne particles I have a ceiling mounted Jet dust dual filter absorbent unit the outer filter at 5 microns ,the inner at 1 micron I believe.Requires removing and cleaning out the filters with compressed air outside the shop when needed.
Now at least I dont have the problem with nasal congestion borne out from early days of not removing that fine stuff that hangs in the air and often unseen!
Perhaps I could have gone with the 6" ducting but after some rennovations I was stuck with all the 4"pvc down pipe and used that instead and am still happy with it.
Just my 2c input!
Good luck bitingmidge
Cheers

Bitingmidge,
regarding the lathe pickup, I recall reading in Aust Woodreview today (library) about a 'posable' hose like the ones on scrollsaws only much bigger for lathes..

From the big Cyclone, I have 6" mains with 6" wyes and 6" getting as close as feasible to the machines. From then on I mainly have 4" with some machines (i.e. the Table Saw) having two 4" connections - bottom and my overhead guard.

The SCMS is the problem child. It is boxed in and has had four or five different configurations of duct/pipe around the saw. The current one is a single 5" pipe fixed/angled at one side. This seems to be the best so far but not perfect by any means. I want to try 6" but the cost of 6" flex keeps putting it off.

As for the bandsaw, mine has a 4" port in the bottom/back of the saw standard. It did have a stupid "dummies" plate inside which I promptly removed (just about covered the port on the inside making it useless). This is clearing out the dust in the saw beautifully but I get dust on the table while sawing. I plan to try a under table duct angled up and aimed at the bottom bearings. Should give a fair bit of suction (I hope) through the table insert which has holes drilled.

The lathe is something I have not plumbed up yet as it is not in a permanent position. It will be soon I hope (subject to planning permission from SWMBO).

Hi b/midge

I still haven't installed my ducting though if it is of any help to you, here's my 2 cents worth:

As much as possible I will use 6" duct everywhere. I don't see much point in going to all the trouble of building the cyclone without extracting as much performance out of it as I can (unless you are retrofitting to an already existing 4" infrastructure)- and as you note, getting the finest dust is the real object of the exercise for the sake of health. You really NEED (according to Bill Pentz) to get adequate airflow for this and 4" doesn't really quite do it; I gather that even just a couple of feet of 4" robs significant performance from what you are trying to achieve.

Instead of cutting round holes and finding suitable flanges (a near impossibility!) to hook up to the machines, I have decided to cut rectangular holes using a metal cutting blade in the jig saw or angle grinder. To connect to the machines I will make rectangular to round transitions out of 0.6mm gal sheetmetal. Most of the rectangles will be 180x100mm because this approximates the area of the 6" duct.

On my tablesaw I don't intend having a hose to the guard above the blade. The main reason is that I use zero clearance throat plates (except for when the arbor is tilted) and 2 GrrRippers in tandem for my "guard". This makes it difficult to use dust collection above the table; anyway very little fine (harmful to health size) dust should come above the table with adequate airflow from below. BTW I have an MBS type overhead guard that is surplus...anyone interested? ...make me a fair offer by pm.

I'm using a LittleRat for most of my routing so I don't have quite the same concerns you might have (this is the only place I will use 4" hose, but I will try to connect two of them in different positions under the 'Rat). I think you're right though in observing that the router table presents the biggest challenge for dust collection.

G'day.

So far I've only done a heap of reading from the books &
Bill what's-is-name's web site.
The 2 main bits, nah, 3 main bits (I forgot about money) to juggle are...

1. Airflow at the machine...
2. Airflow in the ducts...
3. MONEY....

1. To get all the really crook sh’tty little lung bug'ras
you need 800CFM at the machine. (not too techo)
(quoting Bill what's-is-name)
2. Main Line dust airflow should not drop below 3500FPM &
the Branch Line should not drop below 4000FPM.
(ooooww... getting a bit techo now)(quoting text book)
3. Keep buying those lotto tickets. (piece-o-the-proverbial)
(ask the newsagent to help you...DOH!)

Techo analysis according to Cliff.
(I’m no expert, but I can read a book & I can add up)

To make a fixed system...
you will need at least a 2 HP sucker that can shift at least 1200CFM,
an un-complicated 6" main line & two 4" flexi ducts open at any one
machine only at any one time is the best you can hope for on a budget.
One to catch the chunky bits in the line of fire of the tool &
the other cleaning up the air in the general vicinity of the tool.
IE, so you don’t breath it before it hits the floor/wall/door/four winds.

Now, you can take that as good enough & stop reading or,
you can read more of my waffle about this subject &/or
you can disagree. (or clean up my waffle 'cos no one is perfect)

Notes:
I’m talking 'shed' (home workshop) sized machines here,
not the big industrial stuff.

Any dust in the air, even the tiny <1 micron particles, is(are) crook.

Bill what's-is-name's wants to see at least 800CFM at
the working machine to clean the air properly.

The 2HP sucker needs to be able to suck about 50% more than
800CFM to allow for system losses, that’s why I said at least 1200CFM.
For the argumentative types...
this is physics plus Bill what's-is-name's value of 800CFM to get all the
nasties & if you want to disagree, go for it, it’s stuff I read elsewhere,
so it’s no skin off my nose. (I'll just quote the source back at ya.)

One 4” duct with 400CFM through it is just over
the required 4000FPM for a Branch Line.
Two 4” ducts with 400CFM being sucked by a 6” Main Line
gives 800CFM in the Main Line & that is just over
the required 3500FPM for a main line.
(Rocket science, NOT. I got it straight out of a book)

A good cyclone will tax the vacuum in the system so you need to allow
for a more powerful sucker to drive it. (I can’t give you a figure for that)

If you can’t afford a good cyclone & a motor to drive it or
the <1 micron filters, put the exhaust outside the cubby or
you will be breathing recycled dust.

I’m going for a 3HP 3100CFM twin needlefelt filter bag sucker for about $1K.
A length of 6” PVC is about $84. Elbows & joiners are <$10 each.
I already have a 4’’ accessory kit from carbytech for about $80 so
if I stick the sucker outside the cubby, I can have clean air for <$1500 &
I have enough suction up my sleeve to put in some sort of an
in-line crap-catcher (cyclone, drop bin, etc) so I don't have
to empty the bag(s) every 5 minutes.

I can’t go over 3HP ‘cos that requires going to 3Phase power &
I can’t get that in the sticks without a special polyphase converter.

If you are REAL short of cash but still want to do something about
the dust in your shed, & your health, get one of the <30 Micron
2HP 1200CFM units, sit it just outside the door & hook up two 4"
ducts to the machine you are using at the time, one under & one over.
It'll cost you about $300 for the sucker & $160 for accessory kits &
you will have covered all bases. Now set up a cheap $20 fan to
blow the dust coming out of the sucker bag away from you.(neighbour?)
The down side is that you will have to drag the hoses around every time
you change machines & if you can't secure the sucker outside somewhere,
you'll have to drag it out the door every time you visit the shed.
You will also have to empty it more often.

You can do it for less than $500 if you are prepared to drag it around &
empty it often or less that $1500 if you want it fixed & empty it often &
maybe $2K to do it 'right' for a 'shed' (home workshop).

Hope that makes sense, feel free to add to it or set me right.

Nicely summed up Cliff!

I think the costs for the options you mention are at the top end in each category because you are guesstimating with new prices. A more scottish approach can see a fair drop in outlay - secondhand blowers/DC, filters recovered from Mack truck service etc.

The bottom line though is that clean air in the woodworking environment for the sake of one's health can cost significantly; but it is a cost which should be highly prioritised imho.