Best dust extraction for mitre saw

[ScottGoddard]

Hi all - I have the Bosch GCM 12 GDL 305mm Axial-Glide Mitre Saw. Currently i have a dust / chip extractor leading to a 150mm spiral pipe, that i then have a 100mm reducer, blast gate with another reducer to 63 mm.....My question is, are mitre saw better (i know they're bad anyway) with a vac or the current set up i have.?

 

[AJB Temple]

There are a couple of ideas on the internet (you tube) to improve dust collection quite a bit. It mainly involves: add sacrificial fences, add a collector chute extension and remove the right angle exit pipe and connect the house on straight. I use a lidl cheapy vac, of which I have a few, and plug the saw into the power take off point of that. Works brilliantly.

 

[ScottGoddard]

thanks, i have a vac below the saw that can power on start up as well....Just wondered the best approach.

 

[AJB Temple]

I have the same saw and really rate it. No mitre saw has brilliant extraction as the dust can start quite a way from the extraction point on a wide cut.

 

[Gregers]

I built a cabinet around mine with an extractor on the back panel which reduced the total amount a fair bit but it was still a long way from eliminating the dust problem. It appeared that some of the dust was hitting the back panel and eddying back out. There was enough coming out to dust my overalls - and therefore my lungs.

There are some interesting Youtube demos of small one man tents forming a cowl around mitre saws and these seem to do a half decent job of containing dust, and there are also purpose built types available with exhaust outlets which are even better. I attempted this with a cheap mini tent I got from Decathlon but it wasn't really the right shape and was notably unsuccessful.

I recently tried to work out where most of the dust was going by putting a PVA covered board behind the saw and this demonstrated a distinct pattern of dust dispersal. Now I know where its epicentre is, I intend to build new cabinet which will incorporate a big mouth dust hood at this spot with various deflectors at places where my board shows some of the dust is flying. This is currently on hold as the dust hoods are currently out of stock at my local Axy. It should be the best solution, yet, but I still doubt that it will capture everything as most mitre saws are ergonomic disasters as far as dust collection is concerned .

 

[Sideways]

In my experience of a couple of 10" SCMS, the thing that makes the biggest difference is getting a vac attached to the outlet from the blade shroud. If you have a way of getting high volume airflow from around the back of the blade so much the better but you need high suction to get a decent airflow through the narrow hose and port in the back of the blade guard and take as much sawdust directly off the back of the blade as you can.
I regularly use a Makita setup this way with an autostart vac. It still throws a fair bit of sawdust back into a plywood hood built around it, but when the vac fills up and loses suction, then you really notice it. This setup is way better than using the saw with no dust capture.