Table saw dust extraction

[altennis]

I have finally got around to trying to improve the pitiful dust extraction from my table saw, but am a bit stumped as to what to do, any advice would be much appreciated.

I have a Charnwood W650 table saw, which is fitted with a crown guard with an extraction hose coming off the back, with a T joint into the main 100mm port. The saw also has a black plastic assembly around the saw blade itself, forming a kind of hopper, which the 100mm hose is connected through to.

I have a Axminster cyclone extractor that will move 3,700 m3 per hour and a 100mm ducted pipe system (going to upgrade this to 150mm soon). However, even with this air movement there is dust everywhere in the workshop whenever I use the saw. The floor underneath usually has about 10mm after a good sawing session, with further dust being spewed out of the top of the table.

Any advice appreciated.

 

[PAC1]

The problem with most LPHV extractors is they do not work well with small diameter pipes. so if you could increase the extraction underneath to 125 or 150mm diameter it should improve. Also try connecting your crown guard to a shop vacuum just to check if the current arrangement does not work or if the crown guard itself is not efficient at dust extraction. You can buy better crown guards including a SUVA guard which is excellent at both safety and dust extraction but not cheap.

 

[altennis]

Are there any saw guards that you recommend as the SUVA guard itself is a tad expensive!

I have checked and my extractor will take a 200mm duct, so going to put that in rather than 150. However, the inlet on the machine is only 100mm so I guess there will always have to be a length of 100mm hose to go to that.

 

[PAC1]

I have a SUVA so I cannot say but Scott and Sergeant have an after market one as do Axi that is £30-40 from memory whether it is better than your current model I do not know.
As for the 200mm pipe, unless you can change the inlet it is not going to make a difference. LPHV systems need to have an unrestricted flow. It will not suck the air faster through the 100mm section to compensate for the restriction Going from 200mm to 100mm restricts the flow to one quarter of the potential. The air speed stays the same so the volume plummets