Thread: And so the new dust collection installation begins

Originally Posted by scottbr

Can dust collection ever be perfect?

Dust collection usually obeys the law of diminishing returns.
eg Spending $X will get you say 90% of the way there. To get to say 99% you have to spend 10$X and to 99.9% will need 100$X

There are situations (not in wood working) where say 99.9999% of the way is required. An example of this working with radioactive or highly toxic dusts. This is usually achieved using 99.999% efficient HEPA filters and working in space suit type lab wear.

Trying to measure DC air flow is fraught with problems, so unless you are a nutter like me, chances of getting ay sort of accurate measurement is not usually worth the effort.

Originally Posted by BobL

Trying to measure DC air flow is fraught with problems so unless you are a nutter like me chances of getting ay sort of accurate measurement is not worth the effort.

Thanks Bob.

Good to know before going to any effort that attempting to measure airflow is not worth the effort for a non nutter.

Got the flex.
5m of 160mm that fits nicely over 150mm PVC. It looks and behaves like a giant slinky.
And 3m of 50mm to draw from the guard over my table saw.
The plan is to use the flex for runs as short as possible, so I have more than I will likely need.
$223 in total.
Blast gates next.

Slinky.jpg

What sucker are you using on the 50mm off the tablesaw guard?
H.

Originally Posted by clear out

What sucker are you using on the 50mm off the tablesaw guard?
H.

I have a good shop vac, but I'm inclined to plumb the guard into the 150mm PVC that will be running directly behind the tablesaw. I'll try both and see what sucks best.

50mm hose connected to shop vac is better than nothing. You will get better performance if the guard is modified such that the collection point is in front of (not behind the blade) Lappa made a decent one a few years ago.

Originally Posted by BobL

50mm hose connected to shop vac is better than nothing. You will get better performance if the guard is modified such that the collection point is in front of (not behind the blade) Lappa made a decent one a few years ago.

Thanks Bob. I just did a search for Lappa and no luck. I'll have another look tomorrow.

My table saw is a K3 Hammer. Lovely thing, but throws a bit of dust around - the collection point is behind the blade. I have a shop vac connected to it now but I'm hoping connecting it to the 150mm line will be better. We'll see.

Originally Posted by scottbr

Thanks Bob. I just did a search for Lappa and no luck. I'll have another look tomorrow.

Quickest way will be to send him a PM - he's still around according to his activity chart.

Originally Posted by BobL

Quickest way will be to send him a PM - he's still around according to his activity chart.

Ah, Lappa is a person here. I assumed it was a brand name.

Gates are made.
Photos are sideways of course.
Sure, they're not very attractive, but I made them from scraps that have been hanging around for ages.
They accomodate the 150mm pipe and will be bolted to the floor.
Those flanges provide a good seal.

Gates 1.jpgGates 2.jpgGates 3.jpg

Done.
I'll probably have a beer and a dedication ceremony to BobL on the weekend.
The things I did inspired by BobL's posts:
- 150mm PVC.
- Home made gates that the PVC fits inside to maximise flow.
- No sharp turns - 45 degree bends used in series for the two turns I had to make (from the DC and the TS).
- Minimal flex - 1 metre of150mm flex goes to the router, thicknesser and bandsaw.
- Hard connection to the table saw - the biggest dust culprit.
- 50mm connection between the saw guard and main line.


Dust line finished 1.jpgDust line finished 2.jpg

Good work! Its very satisfying to get it all up and running.

One caveat.
Initial testing did show 2 x 45º as marginally better than a 90º, but in ~2017 I did some further testing I found 2 x 45º was about the same as a standard 90º and significantly worse than the large radius 90º bend.

Originally Posted by BobL

Good work! Its very satisfying to get it all up and running.

One caveat.
Initial testing did show 2 x 45º as marginally better than a 90º, but in ~2017 I did some further testing I found 2 x 45º was about the same as a standard 90º and significantly worse than the large radius 90º bend.

I recall reading that, Bob - I read a lot.

The plumbing bits wholesaler didn't have the large radius 90 degree bends in 150mm and they had none at their other stores. They said they couldn't remember ever selling one.

Originally Posted by BobL

Initial testing did show 2 x 45º as marginally better than a 90º, but in ~2017 I did some further testing I found 2 x 45º was about the same as a standard 90º and significantly worse than the large radius 90º bend.

Does anyone know if the orange 150mm electrical fittings attach to 150mm DWV PVC pipe?

247P150 Conduit Bend Large Sweep 90deg Pvc 150mm Electric Orange