extraction question

[selly]

I want to build a little extraction system for the small dusts and wastes such as from the RAS, bandsaw, router, top of saw bench, morticer etc.

I use the extractor for big stuff from t saw and planer but would like to rig up a cheap system using 32mm waste pipe and t joints for all the above and plug it into my wickes wet and dry vac.

this will be cheap but will i be happy with it? It may be up to 5m long and run along ceiling so will I be able to suck enough with vac?

 

[selly]

no opinions?

 

[studders]

I think the Wickes is a rebranded Earlex isn't it? That's what I started out with when money was a bit tight, still got it actually but only use it as a vacuum now. They've got plenty of suck, until the filter clogs, and will do the job but I'd recommend using bigger pipe. I used the Axminster 2-1/2" stuff, it wasn't too dear and worked well so worth the extra. I tried using 40mm waste and it didn't really work.

 

[Sportique]

Sorry, I can't comment on likelihood of success, but suggest, if you go ahead, to use "Y" joints (orientated the correct way :roll: ) rather than "T" joints - to smooth the flow and reduce chance of blockages.



HTH

Dave

 

[ondablade]

I can't comment directly either S, as I don't have experience of using a vacuum that way - most of the information I've collected relates to the Bill Pentz school of thought and systems using full size lower pressure ducts and much higher airflows.

It depends on what you are trying to achieve too. Chip collection isn't too hard, but to maintain what's said to be medically safe fine dust levels in the workshop air is another matter entirely.

What does seem likely is that a vacuum based system might struggle due to shortage of puff to properly gather dust and maybe even chips on some of the items you mention - items like the RAS, top guard on the table saw or even the band saw if it's not a very small one.

An RAS is notoriously hard to hood in such way that it doesn't fling dust and chips all over the place. The people who have done fairly serious work on dust collection tend to go for a 4in duct from a full system to get good collection from a table saw top guard, and to likewise use a lot of airflow and a paint booth like principle on an RAS. Even a band saw often needs a fair volume of airflow as there are typically two (not very efficient) collection points.

There are items about that reportedly collect pretty well off a vacuum - some of the German hand saws and other tools for example. The secret seems to be really careful design of the hood/blade enclosure - if you can reduce the gaps around it enough then with even quite low air volumes as on a vacuum you can stop dust being flung out, and get the air flowing inwards fast enough to capture the remainder...