Soil pipe for chip extraction

[jimmybigfoot]

Hi guys I was just wondering if I could use 100mm soil pipe for my extraction because its cheaper? Is this a good idea? I was going to T off with the proper flexi stuff.
Jim

 

[gregmcateer]

Jim,

I am sure there are a few posts on here about doing just that - do a search and I am sure you'll find it.

Greg

 

[sawdust1]

Hi Jim, 100mm soil pipe is ok, all my extraction is through soil pipe suspended from beams then down to machines via flexi from axminster with blast gates. Use the appropriate soil pipe joiners, 90 degree bends and y joiners where needed, don't forget to lubricate the inner edge of the female parts when joining together.

 

[jimmybigfoot]

Ok thanks guys, soil pipe it is

 

[The Bear]

I think soil pipe is 110mm, just make sure you can connect onto it.

Mark

 

[carlb40]

I use soil pipe in my shop. My system starts with the axi wv1000 extractor.
From the 100mm outlet the soil pipe fits inside the outlet making an easy connection. From there it runs up to the ceiling using Y junctions and the 45 degree bends. I then use the 100mm flexi hose that came with the extractor to connect to my machines. The easy way to connect to the machine if it has the 100mm outlet is to a toilet pan connector. It gives a nice tight fit and can be fitted/removed in seconds

 

[Eric The Viking]

You might want to run some bare wire along the inside (connect it to mains earth at one end), just to keep static to a minimum. It'll be at its worst in the coldest part of the winter, more so if you heat your workshop.

It's belt+braces though. I've heard no tales of soil pipes exploding in workshops because people haven't grounded them!.

E.

 

[Peter Sefton]

I understand the problem can be that the static sparks go into your dust bag and smoulder until they set fire to the contents, not that this has happened to me but an ex fireman student of mine has horror stories on this. On a more general note when setting up dust extraction try and have long slow bends rather than tight 90 degrees and keep the flexible connection pipes as short as possible to keep the air flow efficient.

 

[jimmybigfoot]

Cool, thanks guys. I live in France and the soil pipe here is 100mm. I'll use a joiner to hook it up and get some gates from axminster.
Interesting about that wire (static) though.

 

[chipmunk]

I think that an (easier?) alternative to running an earthed bare wire through the pipes is to insert earthed BZP screws or self-tappers through the pipe walls a little way into the air/dust flow. I think they should be quite close (every 6 inches or so).

These can be wired up on the outside more easily using insulated cable and, provided they don't stick up too high, will not catch shavings or other debris.

The idea is that the points of the screws will effectively discharge the static at low energies before it builds up too much to create ignition sparks.

HTH
Jon

 

[Heath Robinson]

Hi.
I used white 100mm extractor duct from each machine into a main 150mm duct, all available cheaply from eBay. There's lots of joiners, corners, t-pieces and y-pieces, and all the standard blast gates, flexi-hoses and machine outlets fit perfectly.
Check eBay item number 380360874940 as an example.
It runs to one of Cheems 150mm cyclones, with a 2hp extractor fan and motor on the far side. I've heard the "oooh, that'll collapse!" argument against using this stuff, but that's a load of horse manure. If you've specced things right there should be very little vacuum, but high flow rate. Also, if you're using a cyclone, you should have a pressure-release valve in case of blockages anyway.
This set up does a big panel/table saw, a bobbin and a massive disc sander, and a big bandsaw without complaint. It was cheap, looks the part, and was really easy to assemble.
I'd like a 3hp fan and motor eventually, but that's just so I could run a few machines at once. This set up does any individual machine perfectly.
Hope that helps!
Jake

 

[jimmybigfoot]

So, what are the two ends of the wire connected to exactly?

 

[Giff]

I use soil pipe and flex hoses with these http://www.axminster.co.uk/axminster-so ... prod23300/ on each end. I use one or two 100mm flex hoses with these on either end and they just snap on and off different machines.

 

[carlb40]

So, what are the two ends of the wire connected to exactly?

They normally say to connect the earth wire to an earth point on each machine and i think an earth in your fuseboard.

 

[Eric The Viking]

I think that an (easier?) alternative to running an earthed bare wire through the pipes is to insert earthed BZP screws or self-tappers through the pipe walls a little way into the air/dust flow. I think they should be quite close (every 6 inches or so).

These can be wired up on the outside more easily using insulated cable and, provided they don't stick up too high, will not catch shavings or other debris.

The idea is that the points of the screws will effectively discharge the static at low energies before it builds up too much to create ignition sparks.

HTH
Jon

That sounds more sensible than a wire. It will be less of a nuisance to larger chips, and the points will give slightly better corona discharge, I think. Wikipedia's entry on lightning is ambivalent on this though.

I had thought about aluminium tape, like the stuff used with pipework insulation, but it would be hard to connect to, and screws wouldn't be hard to do. Assuming you get a good purchase into the plastic, you might use anti-shake washers and solder tags to connect to them. That makes the whole thing pretty quick and easy.

E.

 

[nanscombe]

I had thought about aluminium tape, like the stuff used with pipework insulation, but it would be hard to connect to, and screws wouldn't be hard to do.

If you used the aluminium tape, surely all you would need would be a nut and bolt passing through tape and out through the pipe to a wire on the outside. If you wanted more surface area add a washer between the head of the bolt and the aluminium tape.

I further assume that you mean using a ring of aluminium foil at a given point rather than trying to pass a piece of sticky foil down the length of the pipe.

With the screws you could place several around the pipe at any given point and electrically connect them together with probably less hassle.

 

[Eric The Viking]

Sorry Nigel - I edited what I wrote but it still ended-up a bit muddled!

It isn't the connection as much as getting the tape properly stuck to the inside surface of the tube. I guess you might pull a balloon through or something like that to push it onto the inside wall of the tube but I can imagine a lot of messing about, Laurel and Hardy style. I've a feeling, too, that they use silicone lubricants in manufacture, and that stuff prevents anything sticking.

I might try it though, as if it can be made to work, it should work fairly well.

I'm sure you're right about the connection though - bolt+wide washers (and solder tag on the outside).

E.

 

[nanscombe]

You could combine a couple of ideas. Get hold of a reel of bare copper (or silver plated) wire like this and wrap it around and run it between two self tapping screws passed through the pipe.