Thread: Eat My Dust

Good job with the stand.

Using the standard 5" connector between the impeller and the bag housing limits the impeller flow to ~680 CFM with clean bags.
This may lead to a potential problem when using 6" ducting where the air speed will be 680 CFM divided by the sectional area of the duct in ft²)
I work this out to ~3500 FPM, which is less than the 4000 FPM recommended by BP to retain all sawdust in suspension within the airflow.

With my full generic 2HP mod the flow rate is 840 CFM so the air speed is 4300 FPM for clean needle felt bags which is also marginal because it will drop below this when the bag clogs up.
A pleated filter will have an air speed of 4700 FPM which will also stay cleaner for longer.

However, I would not now stop from proceeding with 6" ducting but make sure you have extra inspection ports so that you can keep an eye on any build up of dust in the ducting especially along horizontal runs of ducting.

The 4000 FPM won't apply to fine dust from sanders but large volumes of bigger chips such as a thicknesser.
If the chip do build up then shove an "air lance", (PVC pipe with holes in the end connected to a compressor) into the inspection ports to fluff the dust up while the DC is running.
In some industrial setups these are built into the system but I would not do that is it restricts the flow while it is in there.

Looking good!

Nice work. I look forward to seeing the rest of your upgrades!

Trav

Probably a stupid question, but how do you cut the sheet metal for the dust extractor (ie to make the input hole 150mm)? I don't work in metal, just wood. Would a jigsaw with a fine metal blade work ok.?

Trav

Should work fine. I used a jig saw with metal cutting blade to open up my table saw to 6"

I think Safari gives good advice which mirrors my experience. I performed surgery on sheet steel up to about 1.5 mm thick with a metal cutting blade in the jigsaw when opening up ports to 6", such as on the linisher. Worked fine.

Cheerio!

John