|Project by Don Kondra||posted 04-27-2016 07:09 AM||2837 views||4 times favorited||9 comments|
I was looking at purchasing a commercial overhead collection system for ~ $350 (Cdn) but wasn’t impressed that they are mostly 3” mains with an even smaller guard/collection head.
Another thing I didn’t like was having to run another hose to the overhead. Ideally, the whole system would be self-contained with one hose hook up.
While I was mulling this over, I discovered 4” sewer pipe was $16 for 10’ and the 90’s are $6/each
One thing I should mention, I have no need to cross cut sheet goods so the foot print of the system could be quite a bit smaller…
I do rip panels, mostly baltic birch ply for core for veneered panels. They are then cross cut on the SCMS. Cores are 1” oversize and once veneered are trimmed to size/length with a sled on the table saw, hence no need for more than 24” width capacity.
Up until now, I had a piece of plywood between my saw and its base with an inlet for a 5” hose. But it’s the top dust that is nasty and it was time to address this…
To begin, I made a plywood manifold with a cut out at the top to fit over the original 5” starter pipe (easier than removing it), a 5” starter pipe on one side for the main collection hose and a collar for the 4” sewer pipe on the other side, basically a T.
That in turn is screwed to a length of 3/4” plywood which is long enough to also support the sewer pipe before it turns to go up. A couple of metal screws secure this contraption to the base supports !
The upright support is a short piece of wood with two metal screws into the side of the top extension and a hose clamp. That gives me three mounting points for rigidity.
For a collection head/guard I used a 10” x 4” HVAC duct. It’s height right now is high enough to clear my sled and I will decide (after some use) if I need to make something to get closer to the work being cut (without the sled). After a couple of test cuts, it does appear the dust coming off the back of the blade is going straight into the hood…
At the back/interior of the saw I’ve added a couple of pieces of angled 1/4” MDF at the front and back to help with directing the dust into the collection port. For now, I’ve taped the collection hole to balance the velocity between the top and bottom collection points.
Some fine tuning may be necessary but for now, I’m pleased.
-- Don Kondra – Furniture Designer/Maker