Permanent dust extraction

[Baldhead]

I intend to use 110mm underground soil pipe connected to a short length of flexi pipe then onto to the machines, will it be better to have the pipe at floor level or at ceiling level? I know this subject has been 'done to death' but I can't find the answer.

By ceiling level I mean the height of a bog standard garage.

Baldhead

 

[wellywood]

IMHO If it's just dust I would have thought either/or would be Ok. If there's going to be chips or heavy sawdust then low level or the same level as the extract points would seem more sensible to reduce the effort of the extract system trying to lift the heavier particles to high level.

 

[Grahamshed]

What Pete says.
I have mine on the ceiling but it is only dust being moved.

 

[shed9]

I would have thought your available space to route the ducting will dictate the path to some extent.

Personally I would route via the ceiling space as it is less disruptive to other equipment, etc.

Also, I would question the use of soil pipe, it is often a false economy these days. I found that proper spiral metal ducting was not that much more to buy and install, plus it doesn't have any interface issues. It is easier to mount spiral pipe at differing heights from the surface than soil pipe.

Mine is ceiling mounted, metal ducting all feeding into a diy cyclone then into an external exhaust duct.

What length of runs are you looking at and what sort of machines is it servicing as this will also impact your installation.

 

[carlb40]

I was always put off by the cost of metal ducting, but i only ever went by the prices axi charge.

However after looking on ebay a month or so ago, i saw the price was quite a bit cheaper
http://www.ebay.co.uk/itm/Galvanized-St ... 19cd5d0dcf

 

[wellywood]

Shed9 makes some good points but spiral metal ducting has higher frictional losses than smooth bore ducting. If you have only a small system with short runs and a powerful enough extractor, this might not be a problem.
My system is 75mm rigid PE pipe clipped to the wall at around knee height with short flexible take-offs sized to suit to each machine, each take-off is fitted with a spade for isolation when not in use. I also have a take-off to low-level with an open-mouthed catcher at floor level (also with isolation when not used) so I can brush the floor sweepings straight into the catcher.

 

[deema]

There is I believe an advantage to ceiling mounted pipe and this is when the extractor is switch off, the remaining dust in the pipes settles down. If you have it ceiling mounted there is a fairly long run vertically in which the most heavily laden air resides. The dust settles back onto of the blast gate, which instead of solidifying gets scrapped off the next time you open it and then gets sucked back through the system. On the floor, the dust settles in the first elbow and restricts the flow over time without regular cleaning. The other advantage is that it helps to stop large bits going into your system,. I.e. Chunks coming off a router, thin strips off a circular saw. The vertical lift created by the vacuum restricts what can get to the impeller.

I would compare the price for spiral wound metal pipe against drainage pipe, I think you will be amazed how cheap it is! I would look on google for a suitable local supplier. It also reduces the risk of static build up with it not being plastic. Static and dust is an explosive combination!

 

[Baldhead]

If I used plastic pipe, to minimise static could I run a length of unsheathed copper cable inside the pipework and connect it to an earth? or would that not work

Baldhead

 

[carlb40]

If I used plastic pipe, to minimise static could I run a length of unsheathed copper cable inside the pipework and connect it to an earth? or would that not work

Baldhead

You could, but you have to watch it doesn't cause an obstruction inside. I think there is a way to earth the pipes from the outside, you would have to have a google.

I have been using soil pipe ( ungrounded ) for over 5yrs without problems. But that's not to say it can't happen.

EDIT

http://www.woodworking.com/forum/showth ... collection

 

[shed9]

The whole earth or not to earth thing has been rattling around for years;

This makes interesting reading;

http://home.comcast.net/~rodec/woodwork ... myths.html

 

[Peter Sefton]

There is I believe an advantage to ceiling mounted pipe and this is when the extractor is switch off, the remaining dust in the pipes settles down. If you have it ceiling mounted there is a fairly long run vertically in which the most heavily laden air resides. The dust settles back onto of the blast gate, which instead of solidifying gets scrapped off the next time you open it and then gets sucked back through the system. On the floor, the dust settles in the first elbow and restricts the flow over time without regular cleaning. The other advantage is that it helps to stop large bits going into your system,. I.e. Chunks coming off a router, thin strips off a circular saw. The vertical lift created by the vacuum restricts what can get to the impeller.

I would compare the price for spiral wound metal pipe against drainage pipe, I think you will be amazed how cheap it is! I would look on google for a suitable local supplier. It also reduces the risk of static build up with it not being plastic. Static and dust is an explosive combination!

Deema makes some very valid points, I spent the first half hour in the workshop this morning unblocking slices from the extraction pipe off the back of my saw bench, it was a pain but less painful than my extractors impeller taking the brunt of the bits. All the commercial workshops I have seen that have had professionally fitted extraction have taken it to the ceiling. Where is the inlet on your extractor? as if its up high then that maybe your answer.
Cheers Peter

 

[Bluekingfisher]

I have exactly the system you are talking of. Mine is ceiling mounted with my thicknesser over 20 feet away and never had any trouble. I have a a 2HP DC unit with a thein cyclone, which I was told would reduce the suction of the DC but mine clears all debris from the P/T with no problems at either end. In fact it is satisfying to hear the larger chips rattling onto the drum at high speed.

Had I to do it again though I would consider running the ducting at a level lower than the machines, I guess gravity would increase it even more but if you prefer the "high" option you will have no trouble ( depending on DC unit of course)

Good luck.

 

[Baldhead]

Thanks for all the advice, my 'workshop' is a single garage, I have this extractor

http://www.axminster.co.uk/axminster-ho ... -extractor

I intend to make a Thein Cyclone and place the inlet just over head height with the extractor below, so it looks like high level pipework, I have a Planer/Thicknesser, Bandsaw, Table Saw, Pillar Drill, Sliding Mitre Saw, Scroll Saw and a variety of hand power tools (sanders, routers etc) all the larger tools are on castors because I have very little space so each one will be connected via flexi pipe.

Will my DC be strong enough? As each machine is moveable they will not be permanently connected to the DC so I will only need perhaps 3 inlets (each one will have gate valves fitted) When I use the P/T I will probably connect this straight up to the DC.

The reason I am doing this is because I like to work with the door shut and it gets very dusty, when I cut pine on the bandsaw my nose gets very itchy, I've tried wearing a face mask but I wear glasses and they steam up.

Baldhead

 

[carlb40]

I have Axi's version of this
http://yorkleen.co.uk/documents/product ... Extractors

Connected to the ducting it collects about 80% of the waste from the planer and about 70% of the waste from the thicknesser and less than 1/2 of the waste from the TS So not very good at all, hence sometime this year i will change to a HVLP type.

As to masks have a look through a couple of the mask threads from last week. I recommended a 3m mask. It can be used with glasses/ goggles as the vent faces downwards.

So no steamy sessions in the workshop :mrgreen:

 

[Bluekingfisher]

Thanks for all the advice, my 'workshop' is a single garage, I have this extractor

http://www.axminster.co.uk/axminster-ho ... -extractor

I intend to make a Thein Cyclone and place the inlet just over head height with the extractor below, so it looks like high level pipework, I have a Planer/Thicknesser, Bandsaw, Table Saw, Pillar Drill, Sliding Mitre Saw, Scroll Saw and a variety of hand power tools (sanders, routers etc) all the larger tools are on castors because I have very little space so each one will be connected via flexi pipe.

Will my DC be strong enough? As each machine is moveable they will not be permanently connected to the DC so I will only need perhaps 3 inlets (each one will have gate valves fitted) When I use the P/T I will probably connect this straight up to the DC.


oing this is because I like to work with the door shut and it gets very dusty, when I cut pine on the bandsaw my nose gets very itchy, I've tried wearing a face mask but I wear glasses and they steam up.

Baldhead

Im not sure of air movement dynamics but your extractor may?? struggle to shift anything other than dust as opposed to chips through 110mm pipe. Unless you have the thicknesser or large chip producing machines very close to the extractor. Another valuable tip I gleaned from my research was to keep the pipe runs as short as possible and ensure any bends or right angled turns are taken in a large radius turns . I>E use two 45 degree turns or similar rather than a 90 degree socket. It increases the radius of the turns so keeps the air flowing and is much less likely to clog the pipe at that point. Also if you are going to use flexi hose then keep these lenghts to a minimum only the last few inches if possible to join to the machine. It's worth the effort. The corrigations in the flexi hose create drage and increase friction and therefore lessens the efficiency of the system.

Some will tell you to earth the ducting due to static caused by the friction of the moving air. I reckon for a small hobby system this is not required. unless of course you will be moving large volumes of air for long prolonged periods? I havent done so on mine but not a huge job if you are mega cautious and want to ground your system.

I thought I had some photos of my system (110mm soil pipe) on photo bucket for me to post to show you my system I built with the Thein cyclone included. If you would like some snaps of my system, let me know and I'll rummage through my photo files or failing that just take some new pics for you to see what I am trying to explain.

As I say, I am no dynamics expert but I did find that my system does work better than I anticipated despite all the advice and reseach i conducted. I believe your DC is rated at about 1.5HP although I am not sure how a brush motor would compare to an induction motor of similar rating?? That said, in a sigle garage, what is your maximum run lenght? somewhere around 16-20 feet? will all the machine be fed off a single run or do you intend to have runs branching off onto the other side of the shop. Blast gates are a must have so you can dedicate all the suction to one machine at a time. I made my own from 18 & 9mm MDF (cos that's what I had) very simple to make. Another trick I learned was that you can make reducer pipe for the 110mm pipe by cutting a section out of scrap 110mm pipe then cutting a section out of it lenghtwise to compress it into a circumference that will slip into the 110mm ducting. I then welded it together with plumbers solvent pipe adhesive, works for me and my system is almost 3 years old now. If you take your time and get a nice slip fit the solvent weld and the existing 110mm pipe hold it firmly in position without the weld breaking. You could also use a jubilee clip to hold it in place but this is extra expense. You can only reduce the adapted pipe, not increase, least not that I know of.

Good luck anyway,

David