Tuesday, November 19, 2013

Getting a Bit Less Dusty

It was a long and excellent summer, which unfortunately did not include any woodworking.

However, I have been back at it in recent weeks, and have managed to make some progress on the  dust collection system upgrades I started in the spring. I ran all the 6" PVC tubing from outside into the house and routed it to each of the four machines.

I built an insulated box around the cyclone, but I still have to install either a muffler or the dust filter as the noise of the exhaust blasting straight out the impeller is way too loud. Before I built the box/shed the noise was 84 dB at the property line. With the shed it is 80 dB. I was pretty disappointed in the minimal reduction, and there is no way the new neighbours are going to stand for that! Plus the box is extremely ugly. Too late to paint it now though, it'll have to wait for spring.

I do not have a filter on the cyclone though, it just exhausts straight out. I will build a muffler for it with some baffles and hope that takes it down to an acceptable level.

As part of the upgrade from the 4" system to a 6" systerm I had to upgrade the shrouds on most of my tools. This turned into more work than installing the cyclone and PVC ducting!

Only the jointer already had a 6" input on it. I had a 6"-4" reducer on it for the old 4" system, so it was a simple matter to remove that and connect up the 6" hose.

For the planer I just constructed a new shroud out of 1/8" plywood and a repurposed 6" furnace duct. It is ugly and not well sealed but does the job. I may take it to the sheet metal shop and get them to make a nicer one for me.

For the bandsaw, I had to perform some major surgery to get it done. The original 4" pickup was was impossible to modify to 6", instead I had to close it off and cut a corner off the door to install a slighlty modified 6" furnace duct. I was able to mount it such that the saw blade actually runs right through it so the collection is pretty good.

The tablesaw was the biggest headache, my Hammond Glider. It is a design from the 30's or so and was never designed for dust collection. The opening where the blade fits is fairly tight and it would not support the volume of air required by a 6" port. So I decided to utilize a 4" lower collection port under the table in this opening, and a 4" upper collection port over the blade. I had to get a custom pickup for under the table made at a sheet metal shop, then modified it extensively as I installed it.
Not much to see in the photo below, the custom duct is temporarily taped into place on the Glider.
 I did a couple test cuts and discovered that the slot the blade comes up through table in the normal cutting position (below) is way too small to allow any significant airflow, so the dust/chips on top of the saw are not effectively collected. If I lift up the part of the table to the right (as shown in the above picture) the dust collection is fantastic. I was hoping that the undertable collection would be enough, but it looks like I will need to add upper collection as well.

The 6" system moves a lot more air than the older 4" system did. The first thing I noticed when I fired it up on the jointer (same thing happens on the planer too) is that since there is so much air moving over the blades, it actually creates a noise similar to when you were a kid and you clothes pinned a baseball card to your bike frame so it would make a noise as the spokes hit it!