PDA

View Full Version : tablesaw dust extraction



Ivor
12th September 2003, 02:39 PM
Hi All,

I just bought a table saw dust chute, which is just a black plastic square with a hole in it to attach a 4 inch hose. What I can't figure out is how to mount this in relation to the blade. Should it go underneath, on top or behind the blade? Please help.

Thanks

Ivor

Dean
12th September 2003, 03:04 PM
Usually enclosed tablesaws have like a chute (like a slide) within the enclosed base (under the blade and trunnions etc) that slides all the dust down to the collection port that your hose connects to.

What type of saw do you have and does it have an enclosed base?

Ivor
12th September 2003, 03:43 PM
The table saw I have is part of an old shopsmith, so basically it's open to the general environment.

Sound's like I am going to have to enclose the underneath of the aluminum plate and attach the dust extractor to that. I don't think they saw dust as a bad thing back in the 60's when the shopsmith was built.

Ivor

Dean
12th September 2003, 04:03 PM
Ahh right, yep make an enclosure for the base with a flat board angled down to act as a chute so the dust slides down to the outlet.
Make sure this chute plate is coated with something the dust can slide on.

Ivor
12th September 2003, 04:33 PM
Cool,

Thanks Dean

Dean
12th September 2003, 04:35 PM
Ok good luck!
Let us know how you get on.

rodm
13th September 2003, 12:36 AM
I am about to do the same thing to my table saw. The problem I have is that being a a miser I tend to dock (I have a sliding table on my table saw) small sections of timber that always fall between the blade and plate on the saw. The sections are typically 75mm by 50mm by 2mm or so thick. These have until now just mixed up with the sawdust to be picked up later. If I make a slide so that all the material inside the table saw is directed to the hose then is there likely to be a problem with blockages or impeller damage? Has anybody built a wire cage or any other device to capture the larger bits to prevent blockages or damage or am I imagining a problem? Another thought may be to make a closer fitting plate for the table saw/blade width.
Any comments would be appreciated.

Dean
13th September 2003, 12:41 AM
You need a zero-clearance table saw insert :)
Also the dust collector should have a basic grid at its intake outlet to stop anything 'large' hitting the impeller?

rodm
13th September 2003, 01:05 AM
Thanks Dean
Couldn't remember what to call the table saw insert. I will check on the inlet to see if it has a grid. I should remember as I assembled it last night but obviously I didn't take notice before I hooked the ducting up to it.

Dean
13th September 2003, 01:40 AM
Its just a basic grid. But it should stop anything large enough that may damage the impeller. With the zero-clearance insert, nothing large enough should get down there anyway.

Red neck
13th September 2003, 02:14 PM
Basic grids can be a major hinderance. A few of Rodm's off-cuts passing into the hose will stop at the grid eventually blocking the flow of sawdust and reducing dust extraction to zero.

My Delta extractor drove me to the point where I removed the grid with tin snips.

Interestingly my larger Carba-tec unit doesn't have a grid and that is the unit I have plumbed into the table saw. The occasional off-cut goes down the tube, makes a slight ping and passes into the bag. Impellers still look as good as new - on both machines.

Ivor
13th September 2003, 04:45 PM
Dean,

I remember reading something in a magazine about zero-clearance inserts. I think the method to make them went along something like

1. Get a piece of wood the same thickness as the normal insert.

2. Cut a bit out that will fit snugly into the table and screw it in.

3. Start the saw and slowly raise it from underneath the piece of wood so that it cats a hole the same width and length of the saw blade.

This seems fairly dangerous to me. Has anyone actually tried this or is there another way to make them?

rodm
14th September 2003, 10:58 AM
Ivor,

I followed Dean's advice and made a zero tolerance insert. I made it the same as you describe except I clamped a board across the table saw to hold the insert in place while I raised the blade. Worked fine and there was no risk as I did not have to hold it by hand.
One concideration is that if I want to angle the blade I will have to use the original insert to have the clearance to tilt the blade.

Dean,

I have the Carbatec economy 2hp dust collector and it has a pressed metal guard of sorts on the intake side. Basically a crossover piece that will retain any large bits of timber - probably bits too large to be able to be sucked up anyway.

Red Neck,
The impellers are steel and look like they will take a few hits.

Thanks to all