# Question: Dust collection, Table saw and vacuum efficiency.



## Bob in St. Louis (Feb 11, 2015)

Question for y'all.....

When my DC is running, I feel very little air where the blade comes through the guard. I expected a breeze, but no.
On further inspection, I see areas all around the cabinet where ambient air is pulled into the saw cabinet. Now, I feel this is robbing the main area, ("ground zero") for dust/chip manufacturing of very important and needed vacuum. 

The largest offenders seem to be where the cast iron top meets the cabinet (that's over an inch wide and runs all the way around the cabinet) and the large opening the blade elevation shaft comes through (that's about 2" wide and a foot long).

What are your thoughts to sealing these leaks?


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## d_slat (Apr 10, 2012)

A pic or 2 of your setup and the areas in question may invoke more replies...


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## Steve Neul (Sep 2, 2011)

There is just other places for air to pass. There is always a gap between the top and the cabinet. Then where the saw tilt indicator is at there is always a big opening. Anyway for the most part the dust collector isn't for eliminating dust from the shop, it's to remove dust from the saw cabinet so you don't have to shovel it out like you did on old models or on contractor models that just let the dust fall on the floor. If you want to to feel a draft around the blade get some great stuff expansion foam and seal the gap around the top. Then put some duct tape over the tilt arbor indicator slot.


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## Bob in St. Louis (Feb 11, 2015)

Thanks Steve. I thought about the Great Stuff, but before I "went there", I wanted to get folks opinion on the matter. That gap up there is massive.

d_slat, when you have your DC on your saw, do you feel a breeze at the blade, and do you feel a breeze at all of the openings? I figured most saws would be build about the same. I've got a few dozen pics of my saw (in another thread), but haven't taken pics of the "offending" openings as I figured we all had the same openings.


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## michaelpugh (Dec 31, 2013)

I was disappointed in my dust collection at the table saw. Every so often I have to open the side door and push the saw dust to the dc port. It's sucks it right away but I was thinking it would suck it all away without having to do this. The space in front of the port is always clear but the rest of the cabinet gets a lot of build up. I guess it would eventually fall over and get sucked away. Maybe I'm just doing work I don't need to...


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## Bob in St. Louis (Feb 11, 2015)

Yip, mine had about a gallon worth of dust inside the "chamber", but the area in front of the port was clear as well.
I guess it really doesn't matter if the inside fills up, since the port/intake area is clear.
My main goal was better overall collection and the thought process was that if I can make it suck more at the blade, it would help. I guess it can't hurt?


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## Steve Neul (Sep 2, 2011)

Bob in St. Louis said:


> Thanks Steve. I thought about the Great Stuff, but before I "went there", I wanted to get folks opinion on the matter. That gap up there is massive.
> 
> d_slat, when you have your DC on your saw, do you feel a breeze at the blade, and do you feel a breeze at all of the openings? I figured most saws would be build about the same. I've got a few dozen pics of my saw (in another thread), but haven't taken pics of the "offending" openings as I figured we all had the same openings.


I have a harbor freight dc hooked up to unisaw only with a 10' flexible line. I do feel a little air around the blade but not much. When running the saw I do get dust all over me when I'm cutting. I just don't have to get down on my hands and knees anymore and shovel dust out of the cabinet anymore. 

Go easy with the great stuff. You don't want to get it into the mechanics of the saw.


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## michaelpugh (Dec 31, 2013)

I've been wanting to build something to hang over the blade. A guy I like to watch on YouTube has a setup that he can raise out of the way but otherwise it hovers over his work and looks like it would work great...course I have a million projects going so when will I get to that one???? Who knows.


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## michaelpugh (Dec 31, 2013)




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## Oneal-Woodworking (Apr 14, 2013)

Thought Steve gave you some excellent advice. :thumbsup:


A larger and more powerful DC may be another way to go. Something dedicated to the tablesaw perhaps... :smile:


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## Marv (Nov 30, 2008)

Bob..I am using a 1.5hp Delta with an Oneida Super Dust Deputy Cyclone coupled to a 5" mainline with 4" to the saw cabinet and 2.5" to the blade guard. I have very strong suction at both places (the blade guard will actually suck up small chunks) and the inside of my cabinet stays pretty clean. I originally tried sealing up the entire cabinet and found it actually decreased efficiency since the only place for air to enter was through the tiny blade slot. I left the foam in between the top and cabinet but took off the cover I had over the front slot and had a dramatic improvement. 

Also, below is my solution for collecting as much dust as possible on top of the table. 
http://www.woodworkingtalk.com/f2/shop-built-table-saw-overarm-dust-collection-hood-45394/
It is extremely efficient with through cuts however when I "buzz" the edge of a work piece dust spews out of the side so I'm actually working on a third version hood with dual pivoting sides to rectify this problem.

first version










current version


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## Bob in St. Louis (Feb 11, 2015)

Oh my!!!! 
That's more than a tool, that's a work of art.
Thank you.


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## michaelpugh (Dec 31, 2013)

There's a better picture of it.


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## woodnthings (Jan 24, 2009)

*it's aerodynamics*



michaelpugh said:


> I was disappointed in my dust collection at the table saw. Every so often I have to open the side door and push the saw dust to the dc port. It's sucks it right away but I was thinking it would suck it all away without having to do this. The space in front of the port is always clear but the rest of the cabinet gets a lot of build up. I guess it would eventually fall over and get sucked away. Maybe I'm just doing work I don't need to...


Most table saws fill the cabinet in such a way as to allow a smooth air flow into the DC port. It's a strange phenomenon but I don't think it's a big issue. It like you are in a dust storm in the desert and the wind blows around certain things with a smooth air flow.

To be really efficient, use a over the blade collector like Marv. The blade spits a lot of dust right back at you because of the tip velocity, and in the gullets where it can't get sucked out. I made mine from 2" PVC and hooked it to a separate shop vac with a lot of suction. Works great when I use it.
http://www.woodworkingtalk.com/f7/dust-collection-woodnthings-shop-part-1-a-20273/










http://images.search.yahoo.com/yhs/...fr=ytff1-gl-gen1&hspart=mozilla&hsimp=yhs-006


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## Marv (Nov 30, 2008)

Bob in St. Louis said:


> Oh my!!!!
> That's more than a tool, that's a work of art.
> Thank you.



You're welcome and thanks for the compliment! Here's what everything is connected to and although you can't see my saw it is just to the right of the dust collector since it is my biggest dust producer.


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## Bob in St. Louis (Feb 11, 2015)

That's fantastic!
Probably cleaner that your average hospital!


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## michaelpugh (Dec 31, 2013)

woodnthings said:


> Most table saws fill the cabinet in such a way as to allow a smooth air flow into the DC port. It's a strange phenomenon but I don't think it's a big issue. It like you are in a dust storm in the desert and the wind blows around certain things with a smooth air flow.
> 
> To be really efficient, use a over the blade collector like Marv. The blade spits a lot of dust right back at you because of the tip velocity, and in the gullets where it can't get sucked out. I made mine from 2" PVC and hooked it to a separate shop vac with a lot of suction. Works great when I use it.
> http://www.woodworkingtalk.com/f7/dust-collection-woodnthings-shop-part-1-a-20273/
> ...



That's what I wanna do. Yours looks pretty straight forward.


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## michaelpugh (Dec 31, 2013)

Marv said:


> Bob..I am using a 1.5hp Delta with an Oneida Super Dust Deputy Cyclone coupled to a 5" mainline with 4" to the saw cabinet and 2.5" to the blade guard. I have very strong suction at both places (the blade guard will actually suck up small chunks) and the inside of my cabinet stays pretty clean. I originally tried sealing up the entire cabinet and found it actually decreased efficiency since the only place for air to enter was through the tiny blade slot. I left the foam in between the top and cabinet but took off the cover I had over the front slot and had a dramatic improvement.
> 
> Also, below is my solution for collecting as much dust as possible on top of the table.
> http://www.woodworkingtalk.com/f2/shop-built-table-saw-overarm-dust-collection-hood-45394/
> ...



Marv. That looks very awesome. Love it. If you wanna get rid of version 1 or two you could send it my way


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## michaelpugh (Dec 31, 2013)

Marv, could we see a pic further out when you get a chance? I'd like to see the whole set up. How it hangs etc.


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## Marv (Nov 30, 2008)

michaelpugh said:


> Marv. That looks very awesome. Love it. If you wanna get rid of version 1 or two you could send it my way


Thanks Michael and I gave version 1 to a friend already however you are welcome to version 2 as soon as I get version 3 finished (I'll be posting a thread on the build and just remind me when you see it)



michaelpugh said:


> Marv, could we see a pic further out when you get a chance? I'd like to see the whole set up. How it hangs etc.


Here's the original thread on the build...
http://www.woodworkingtalk.com/f2/shop-built-table-saw-overarm-dust-collection-hood-45394/


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