Thread: Installing my Dusty - WIP

I'd like to see other videos, like mine, of other shrouds with the saw blade actually running with the extractor on, before I will totally condemn the current design. I have some minor tuning in mind but no major changes anticipated. I believe the front shape creates a vortex that prevents fine dust leaving the front but I will need to test this with a smoke machine rather than strands of wool.
As the shroud lifts, it moves forward. At the height the test was done at, the front of the blade was 50mm back from the throat and well in the area of the side draught.

After watching the video again I realised that the wool strands at the front of the dust shroud were not moving at all - not moving out when the saw started and not moving in with the extraction on. This meant one of three things:

1) there was no air movement at all at the front of the shroud
2) there was air movement but so slight that the wool did not detect it
3) something was wrong with the test procedure.

Turned out it was 3) and probably 2).

In the picture below, you can see that the wool strands at the front were in fact placed 60 mm away from the actual shroud opening. This included a flat 25mm section and a 35mm tapered section. That's a big ask to get movement of the wool, lying on the table, at that distance. On the sides of my shroud and on other pictures on this forum, the wool is only approx 6mm max. from the low pressure extraction area.

blade shroud measurement problems.jpg


So I revised the test, placing the wool strands close to the front edge of the cavity and re ran the tests. The correct placement showed that there was in fact air movement both positive (outward) with the saw only running and negative (inward) with the saw and extraction running so no need for major design changes.

https://youtu.be/Yd9v-CKk1pU

The other point about this particular shroud is that its designed for cutting panels or ripping, not cross cutting, that is why it is so narrow. It actually sits on the wood at the front and both sides with only the back open so there is no gap between the guard and the wood as shown in these test videos.

guard covers panel.jpg


Decided to shoot another video showing black saw table top before, during and after a panel cut. As I saw previously - shroud works great for what it was designed to do.

https://youtu.be/UDOyV8MiU1c

Cheers

It looks like it works pretty well. Better than my dust spewing hunk o junk.

Terrific and well spotted.

Even though its not designed for it, it would be good to see how it goes cross cutting?

Thanks Bob.
I have two cross cut sleds. The one I normally use is this one.

crosscut sled.jpg

The reason I didn't design the dust shroud for this sled, is a dead extraction area that occurs between the timber being cut and the saw table on the RH side. This is easily seen in the following video as the dust exiting below the timber being cut, not from above..

https://www.youtube.com/watch?v=HPtFEOKw1iA

The amount of dust is greatly reduced but not eliminated due to this dead spot. I have a hole in front of the saw blade, but this is 1/2 covered by the sled. I believe if I opened the hole in front of the blade on the RH side, the lower extraction may improve this problem significantly but probably won't eliminate this. That's why I said from the beginning that this shroud wasn't for cross cutting.

Still pretty good though!

I think I may have come up with a really important reason why your hood and a number of similar hoods work so well.

It can't be air flow because shop vacs and narrow ducting simply don't carry much are.

I think it is the angle of the inside front of the hood which will reflect the air/dust up into the intake of the of the ducting.

Like this

IMG_0394-2.jpg

Because I have always wanted to be able to see the start of the cut and blade clearly I have always angled the inside front of my saw hoods the other way and used transparent material for the front of the hood.

However, if the hood is angled the other way the spray is then reflected down onto the table so even more suction is needed to collect the dust.

For the mens shed I'm going to see if I can design a full transparent version.

Originally Posted by Lappa

Lots and lots of pipes

https://www.youtube.com/watch?v=JBmdyd7sJiw

Video has been replaced - had my hoses connected incorrectly

https://youtu.be/dkPOqmROs8Q

Can't imagine how you could have become confused and hooked it up wrong.

Yeh. It does look like a bag of licorice down in the corner with all the black pipe

Hi Lappa,

How does your system go when cutting a thicker piece of wood, say 30mm, particularly when cutting less than a blade width? I found that this was one of the tougher situations and required front bristles; in my case thin rubber strips at the front of the guard.

Are you referring to ripping or cross cutting?

This hood, as I said from the start, was never designed for cross cutting. It was designed mainly for cutting up panels. It's designed so the hood sits flat on the timber being cut. At 30mm, the hood would be too high and would need a flexible skirt to help seal.

If ripping a narrow strip off the LH side, I believe I would also need the add a skirt of some description to help seal the LH side as it would be 30mm off the ground. Interesting point re ripping. I'll have a look as see what I can come up with

Ah ok. Yeah I mean ripping and cross cutting particularly when only taking off a blade width or less. You will definitely need a skirt on the front at least in this case. Otherwise you'll have a heap of dust firing forward.

I'm at the stage where I'm connecting my router table and fence and building a dust cabinet for my SCMS (lots of great ideas in the posts started by Chris Parks).

AS I want to move a single hose from one unit to another, I built these adaptors.

IMG_0503.jpgIMG_0504.jpg

I have a Triton MOF001 mounted in the table. Before installing my dust system, I had it connected to a VC with a 32mm hose from the dust shroud and a 32mm hose from the fence to a single port. I'm still unsure of the mods. I need to to make to connect to the new system - lots of pros and cons.

I actually posted a list of questions in the Router forum and would appreciate some feedback

Triton router in table and dust collection set-up

Cheers

Originally Posted by Lappa

Getting there
Yes, it does look like the ClearVue stuff . I priced theirs - but I like my price better

Hey Lappa,

where did you get the Flexi hose from?