Which size dust extraction tubing should I choose? 100/63mm

[Tetsuaiga]

I'm looking at getting some permanent wall tubing set up so I can connect multiple machines and not have to constantly be reattaching my extractor.

My extractor is one the cheaper ones available and has a 100mm outlet but most of the machines I use including the two main ones that I want to connect, a bandsaw and router table have 50mm extractor ports.

Would I be best getting the 100mm pipes or 63mm? That's the option on Axminster at least which is where I normally buy from.

I will probably want to upgrade to a more powerful extractor eventually if it makes any difference.



Thanks

 

[woodcrafter]

Go for the biggest section your budget allows. Bigger pipes mean better evacuation of chips and dust and less likely to get blocked up if you are doing much thicknessing, or machining a wood such as hemlock.
You do not have to purchase specialist woodworking vacuum tubing - any kind of pipe will do. 4 inch Plastic drain or rainwater pipes form B&Q will work just fine. they are a doddle to install and will probably be very much cheaper than Axminster's range.
C.

 

[CHJ]

Certainly the bigger Ducting if you are to have more than one input source connected, the only caveat is the volume of air that is being moved along the ducting.

To get the moving air to carry the debris it has to move at a sufficient rate to avoid the debris dropping out and lying in the lower reaches of the duct.

You say your extractor is low powered, this may be a problem if you have larger diameter ducting as the smaller equipment connections will throttle the airflow.*

You don't want debris settling in the larger pipe due to lack of airspeed, you may be able to negate this risk by making sure you have a natural fall on the larger ducting with no 'drop box' situations.

* You are already suffering from this problem, although not of any significance to you at the moment, as the extractor is obviously designed to move larger quantities of lower pressure air with its 100mm duct and you are restricting its input volume with the 63mm equipment outlets.

Connecting more than one 63/50 mm 'open' source to your ducting will allow the airflow to increase and carry the debris better but at the same time will reduce the effective 'suction' at the individual equipment.

 

[Jamesc]

Hi, I spent many years designing ductwork systems, the subject is vast but in a nutshell if you have a 100mm connection on the extractor keep all the tubing this size. The thing that keeps the waste air borne is the velocity of the air, if you increase the size of duct thaen the air velocity will go down and the dust will tend to accumulate. This is also why you should use as large a radius as possible sweep bends.
From this it would seem that small ducts may be an advantage, unfortunately it is very unlikely that your extractor will be man enough to full sufficient air through the smaller duct.
With regards the change to a large extractor unless you go for an industrial unit then it will have a 100mm connector so the above applies.
On last point, if you do have to reduce the diameter then keep the reduced section as short as possible. If you want to look up what this does Google Venturi.

Regards

James

 

[Tetsuaiga]

Wow thanks for all the advice. Seems like there's quite a bit more to this subject than I imagined.

I will only need a small amount of travel distance so i'll go for the 100mm stuff, maybe just cheap drain pipe stuff and see how it works out.

 

[MMUK]

In my old workshop I had a 4" soil pipe main rail with short flexible smaller diameter hoses to machines. My extractor at the time wasn't brilliant so I fitted an inline blower to the end of the 4" pipe, blowing in the direction of the extractor bin. This made a massive improvement to the system for a fraction the cost of a new extractor unit.

 

[MARK.B.]

Would it be a daft idea to have a couple of rodding eyes in the pipe's just in case of a blockage's ? .

Just asking as i dont know so if its a c rap idea please be gentle when you crucify me

 

[DMF]

Would it be a daft idea to have a couple of rodding eyes in the pipe's just in case of a blockage's ? .

Just asking as i dont know so if its a c rap idea please be gentle when you crucify me

Hi, never used drainage pipe for air runs so i don't know either for sure but if you do get crucified but still remain concerned lol then think about pipe runs you have and use slip collars instead? That way you can just take pipes out as needed - but it's not drainage anyway, might not be two permanently fixed points to cause access probs? Of course this doesn't cover every situation, if your going hidden then yeah stick rodding points in! :roll:

Dean

 

[Tetsuaiga]

In my old workshop I had a 4" soil pipe main rail with short flexible smaller diameter hoses to machines. My extractor at the time wasn't brilliant so I fitted an inline blower to the end of the 4" pipe, blowing in the direction of the extractor bin. This made a massive improvement to the system for a fraction the cost of a new extractor unit.

Interesting, they seem cheap so if I have problems i'll probably consider trying that.

 

[WoodchipWilbur]

In my old workshop I had a 4" soil pipe main rail with short flexible smaller diameter hoses to machines. My extractor at the time wasn't brilliant so I fitted an inline blower to the end of the 4" pipe, blowing in the direction of the extractor bin. This made a massive improvement to the system for a fraction the cost of a new extractor unit.

I know this thread goes back a long way but I've only just arrived...
You say you "fitted an inline blower to the end of the 4" pipe". Which end? At the far end, it's sucking in a lot of air and, presumably, dropping the suction at the machine (saw, planer etc). At the near end (to the extractor) it will have to deal with a whole lot of dust and chippings.