Miter Saw Dust collection hose

[John Hemenway]

John,
From the little bit of testing I have done so far with just the downdraft from underneath. it looks to me like the hose idea would work fine. I think the hose would need to be very flexable so it would not interfere with the swinging movement of the saw. I have seen pictures of others who have done this so I was hoping to get some input from them. I am also interested in sources for fittings and hose. I can get 1 1/2" flexable hose from a vacuum cleaner shop locally, but I was wondering about fittings. I guess I could use 1 1/2" pvc fittings but was wondering about other ideas and what others have done.

Of course for testing/mock-up purposes you could always use duct tape to fit hose to saw. Just make sure you explain to any visitors you are only testing this setup, it will look better when you get it just the way you want it!

There are many hoses to choose from. I've seen flex hose used in hot tub installs, vaccum cleaners have flexible hose, etc. If the hose was long enough to go into DC hole when at 45 degree miter and bevel it might just bow up or go further down DC hole when in 90 degree miter/bevel.

As others have mentioned, it seems like some sort of box behind the saw would be good to contain all the dust the saw bounces off the blade and gets tossed all around. On my saw with no DC and not even the bag to collect dust, about 90% of the dust falls behind the saw within one foot either side.

[JayStPeter]

Larry,

I have the Delta cousin of tht saw. I gota a piece of carwash vac hose, 2"id I think and had some of a rubbery hose adapter left over from a project. I was able to make a bushing with that and got a tight fit. I am sure that folks are going to think I am crazy using a 2" hose ( I only use a little over a foot of it). This seems to catch 85-90% of the dust. I was really suprised. I do keep a second blastgate open to keep air flow going. I have nothing under that saw in the way of dc. I think when they redesigned that saw they had DC in mind. I think that split fence that is pain to get both sections square is that way to a llow a clear path to the dc port. Now if some one will make a CMS with a 4" port.
Joe

I did basically the same thing. I use a shopvac hose with no hard plastic end and cut off a piece of a rubbery adapter (from the Ridgid/Shopvac connection section at HD). The piece is a rubbery adapter that's meant to adapt 2 different hose sizes. I chopped off the smaller size and use it as a gasket for the shop vac hose to fit over.
IMO, those who think you need a 4" hose are all wet. In my experience with the Delta version of the saw, too much airflow pulls the plastic deflector behind the blade forward and actually decreases capture. I go from 6" - 4" - 2.5" to adapt the 6" PVC. I think the 4 - 2.5" adapter is in the same section at HD. Until I build the under saw DC like yours, I have to open another blast gate to keep from having too much airflow at the port.

Jay

[Ken Garlock]

Well, I guess I will jump in since we all have opinions, and everyone knows what they are like.

I am in the process of building the miter saw workstation that was featured in Shop Notes, last issue. As I was looking for a dust removal solution, I happened to get a catalog from Air Handling Systems In the catalog they have helpful hints interspersed among the parts. One hint was to use a metal reducer under your miter saw, just like Larry has done.

The difference is that they recommend putting split rubber tubing around the edge of the large end and push it right up to the bottom of the saw, or at least as far as you can without interfering with the saw miter table movement. They also said to ignore the 1" outlet by leaving the bag in place

Air Handling Systems is a quality operation that among other installations, has done the New Yankee Workshop system. Their stuff is pricey, but good.

[Larry Browning]

The difference is that they recommend putting split rubber tubing around the edge of the large end and push it right up to the bottom of the saw, or at least as far as you can without interfering with the saw miter table movement. They also said to ignore the 1" outlet by leaving the bag in place
.

"Split rubber tubing"???? What is that? Are you saying that there needs to be some kind of an enclosure that sort of seals around the bottom of the saw? Maybe kinda like weather striping only thicker?
Edit: Maybe if I had a piece of sheet metal and took a garden hose and split it and put that on one edge of the sheet metal and then placed that around the hole I cut in the table extending it above the table to where it just touches the bottom of the saw.

[John Hemenway]

Well, I guess I will jump in since we all have opinions, and everyone knows what they are like.

They also said to ignore the 1" outlet by leaving the bag in place

Air Handling Systems is a quality operation that among other installations, has done the New Yankee Workshop system. Their stuff is pricey, but good.

Well that's not exactly like the system they set up for Norm. Of course not everyone has central Vac to go along w/ the DC.

I don't see why you would want to block the path the saw dust WANTS to take. I figure a path to direct this stream of saw dust to the DC would be a good thing as long as it doesn't interfere w/ bevel/miter movements.

Now if only I could get Larry to test this hypothesis!

[terry richards]

I have made several adapters out of wood, when going from smaller to larger with the air flow. Turn a donut in the lathe with a small ledge on the outside to catch the lip of the larger pipe. Turn out the center to whatever diameter you need. Leave a slight lip on the back side for the smaller tube to bottom on. Seal the small tubing into the donut with liquid nails or something similar. Put a couple of small screws through the larger PVC into the donut, so it can be removed if necessary. Finish the seam with a couple turns of duct tape.

Works great - totally customized - and cheap.

TR

[Ken Garlock]

"Split rubber tubing"???? What is that? Are you saying that there needs to be some kind of an enclosure that sort of seals around the bottom of the saw? Maybe kinda like weather striping only thicker?
Edit: Maybe if I had a piece of sheet metal and took a garden hose and split it and put that on one edge of the sheet metal and then placed that around the hole I cut in the table extending it above the table to where it just touches the bottom of the saw.

Yep, that is what I understand. Put rubber tubing over the edge of the reducer and slide it up to the bottom of the saw. In their example, they used a 10 in to 5 inch reducer. In your case a 10 to 6 would be the choice. They claim that "it gets almost all the dust," which is open to interpretation.

Yes, I was surprised that they just ignored the 1" outlet with the bag.

For about 37 dollars, you can get a reducer that will knock your socks off. Check the AHS website that was high lighted in my original post....

[Larry Browning]

Yep, that is what I understand. Put rubber tubing over the edge of the reducer and slide it up to the bottom of the saw. In their example, they used a 10 in to 5 inch reducer. In your case a 10 to 6 would be the choice. They claim that "it gets almost all the dust," which is open to interpretation.

Yes, I was surprised that they just ignored the 1" outlet with the bag.

For about 37 dollars, you can get a reducer that will knock your socks off. Check the AHS website that was high lighted in my original post....

Ken,
Unfortunely I cannot just slide the reducer up into the hole I cut in the table. If you will notice on the 2nd & 3rd pictures I posted. there is a hood of sorts mounted under the table that has a 8X6 reducer attached to it. The reducer fits to the outside of the hood and is offset from center of the 10" hole in the table. I was thinking that I could get a piece of sheet metal and attach that around the table hole extending above and below the table. Below the table it would extend down and attach to the hood. I could then cut another small hole in the top for the 1 1/2" hose and a hole in the sheet metal extention to route the hose into the DC.
However, I guess I could just start all over with a 10X6 reducer and dump the hood all together. I will keep you posted. Maybe by the weekend I can have this built.

[Ken Garlock]

Larry, the important thing is that you feel that it is working as you like. I am sure there are more than one solution, and I was just adding what another company recommended. I see your problem, and I am sure you will end up with a good installation.

[Larry Browning]

Well, I finally was able to test this idea (kinda) last night. I added a piece of cardboard sot that it extended up to the bottom of the saw, and the vacuum cleaner shop sold me a used 1 1/4" hose for $5 that I hooked up to the dust port on one end and then thru a new 2" hole in the table, then thru another hole in the cardboard and just sort of layed into the DC ducting. I turned on the gorilla. There was a noticable increase in suction thru the saw, but very little air flow thru the hose. I cut a few boards and noticed that there was still a bit of saw dust/chips escaping as it left the blade. I would have to say it is picking up maybe 85-90% of the saw dust. I think that I need to figure out a way to increase the suction in the hose.
Now I am no engineer, but I think if I was able to increase the size of the hose to about 2" and then somehow tap directly into the pvc pipe I could increase the airflow in the hose quite a bit. I am pretty pleased with the downdraft part of this and I think extending to the bottom of the saw is a good idea. I had an idea as to how to do this permanently that I thought I would propose to see what you think. Instead of making the extention out of sheet metal I was thinking I could take a plastic 5 gallon bucket with the bottom cut out of it and fit that into the hole in the table. After getting it cut to the proper fit under the saw I could add some weather stripping or even rubber hose around the top to sort of seal around the saw. What do you think of that idea?

[Joe Meazle]

I gots 2" hose if you want some. I will even mail it if you want. I would avoid that 90 degree pvc fitting, if it were me. I tried to give the chips and dust a straight shot since the saw propels them in that direction anyway. I think that fitting would impead and maybe even make some bounce back. i am just guessing. I also used as little 2" as possible.

Joe

[Chris Padilla]

Larry,

Be sure to make yourself a ZCI (zero-clearance insert) in place of what you have. This will also help direct dust AND keep chunks from falling underneath and give you cleaner cuts of course!

[Roger Bell]

I have been experimenting with CMS dust collection for several months. I started out using a rear mounted hood. The rear hood alone just was not catching enough dust. I used the "Big Gulp" plastic hood.

I then tried the 10"-5" spun reducer idea from Air Handling Systems with my CMS as shown in their catalog. I found that it worked much better than a stand-alone hood placed on the back of the saw with NO downdraft. But relying on the stock dust bag to capture the remainder of the dust was a bad idea. Too much dust was blowing out the back for my tastes.

I have since found that using BOTH the downdraft AND the rear hood work best. Both the hood and the downdraft have separate hoses going to a Y in a central DC. Using both, I am capturing "almost all" of the dust. There does not ever appear to be any airborne dust using this combination.....just a few crumbs in the crannies of the saw towards the back. I think that a better custom fabricated sheetmetal hood will likely capture that. There are a number of guys who have made these and there are pictures available.

I have a 45 degree one inch pvc elbow fitting placed on the dust-bag fitting on the saw (Dewalt 705) which can be hand rotated to direct the dust when the saw table is moved around for angled cuts. The pvc fitting works well.