how to measure dust collection efficience

[Alan m]

hi all
i am always trying to improve the dc on some of my tools such  as tha router , chopsaw, etc
i bought a new chop saw a dewalt 703, to compiment my dw718. i did this because it was cheap , small to carry upstairs and up ladders etc, had some dust going up the pipe so a decent start.

back to the point. i want to impove the dc on it . what i am wondering is how to measure it fast and easily. i want to know if i am going in the right direction
my plan was to build a box and put the saw in it. new bag in the ct and make 10 cuts . sweep up the dust in the box and weigh it against the dust in the new bag.

anyone able to come up with a better way or a way to improve my method.

 

[harry_]

I wouldn't bother measuring what's in the bag. No point in it. If it is not in the box, then (in theory) it is in the bag.

cut,
measure,
tweak the set-up,
(rinse,)
repeat

 

[Kevin Stricker]

It's going to be tough to get an accurate measurement with only 10 cuts as the dust you are going to be collecting is going to be pretty insignificant.  Another big challenge is that on a miter saw you tend to spit a bunch of dust out the back and a bunch ends up in the air.

I would probably weigh the wood sample and the CT bag before the test and again after say 25 cuts.  This gives you your base reading on material and how much ends up in the bag which should give you a better measurement on efficiency.

 

[Alan m]

yes 25 cuts would be better.
i was planning on cutting the cuts at full capasity of the saw (with  in reason). with a kapex with dc there wouldnt be a lot of dust in the box but with my dw 718 there would be a lot, that thing has no dc efficiency ( i would say less than 1 % max )

i dont need it to be 100% accurate as i only want to know if i am going in the right direction. some previous improving  had mixed results. i changed where the dust was thrown but didnt know if i was makeing it better or worse