Dust Collection

Hokay, heres what needs to be done with the dust collection.

Extraction Unit Home

Theres a concrete bunker around the back where the compressor lives. We need to rebuild around that to make a shed that can fit both comfortably. I’ve estimated about 60m of standard framing pine, bunnies is the cheapest price there. For walls we have a heap of roofing offcuts around the place we can screw on there in a tile style to weather protect it all.

Essentially need to buy the timber and get going. I’ve already bought a heap of appropriate screws and masonry anchors etc.


As for the ducting, I’d like to pipe in a main bus thats 8", and we can reduce that down to 6" for drops to tools. Theres some argument for going straight to 4" but the cost difference is negligable and keeping the bus as wide as possible for as long as possible is ideal.

Blast gate placement will be as close to the main bus as possible as thats optimal for reducing the area to pull a vacuum on.

You can check the Woodwork 2017 thread for an initial concept about bus layout.

Materials wise I’m looking to utilise DWV PVC pipe, do all bends with 45º elbow pairs to reduce corner radius. Join everything with aluminium plumbers tape, which will seal well but not lock us in like pvc cement would.

Air Filtering

I think we may have two gated ports on the main bus in the middle of the room to open for air filtering purposes.

Down draft table

Might be part of the outfeed table or another piece of furniture, but a down draft table for sanding would be very nice to have.

Sweep Ports?

We may drop a few lines to the ground with a shroud so you can sweep directly into the system, make cleanup super easy.

Blast Gate Automation

This is the parts list to actuate a gate. Gates are about $12-20 depending on material, size etc. Aluminium gates might be worth it just for durability. 100mm piston is 4", 150mm for 6", 200mm for 8". We’d need a few minor one off parts, like a regulator for the air system.

Automation Electronics

We will need to detect tool on and actuate the right blast gate open. I think perhaps this may be best done with a central controller of some kind because of a few factors:

  • There needs to be simple timeouts to extract post machine shutoff
  • The motor shouldnt be cycled on/off constantly, once every 10-15min, so some smarts about staying on or not etc.
  • We need 3 gates open min at any time, the machine is powerful and any less will stress it out with not enough air flow. So a smart controller can try and pop air filtering general ports to meet that minimum number.

None of this is scary stuff to figure out. Might decide to go with 24v control just for voltage drop management over runs.

We should be able to detect ‘tool on’ with the simple current detectors that you can buy on ebay. I dont want to piggyback or interface with any interlock stuff because I want the system to stand on its own.

May need some manual switching as well, just for things like hand power tools, or force the system on for air cleaning, or sweep ports.


I think thats about it? Thoughts? Concerns? Offers to help? Much appreciated.

With regards to the Piping it will be important to keep duct velocities up … eg 25m/s in the runners and 20m/s in the main bus not sure of the flow on the collector itself so this may already be worked out but i would have thought 4" for tools and not 6".
Automating the system sounds great but given its complexity i would question its longevity as well as having it reliant upon the compressed air system to operate.
Just my 2 cents

The collector itself has an 8" input, and I’ve seen much much smaller machines use 6" to tools so I’m pretty confident it will be fine. Its a big beastie. When I consulted with the manufacturer they stressed that the system needs to be reasonably open because it pulls so hard that if you only run one tool it starves for air.

This particular method of automation is quite common around the internet, we’re definitely not inventing anything new. I’m not going to let an automation requirement block any other works but if someone wants to take it on as a project itself and work on that while we get the rest going, that would be super useful.

I’m happy to rely on compressed air for the system, if the compressed air fails I’m sure we’ll replace or fix it in short order.

Just FYI I’ve taken on the automated gates setup and have ordered everything for prototyping a 6" and an 8" gate except the gates themselves as I’ve been unable to find the 6" and 8" in a reasonable price (for the cast ones at least).

If someone can find me a price that is closer to $50/gate or even below it that’d be great.

6" Self Cleaning Cast Aluminum Blast Gate Cut Off Valve for Dust Collector ABG6 | eBay

6" Diameter Dust Collection Industrial Blast Gate - Hvac Controls - Amazon.com

8" Diameter Industrial Grade Dust Collection Blast Gate - Hvac Controls - Amazon.com

6-inch Aluminum Blast Gate Dust Collection Fitting - Woodcraft

70167 Aluminum Blast Gate, 6-Inch - POWERTEC

6" Self Cleaning Cast Aluminum Blast Gate Cut Off Valve for Dust Collector ABG6 | eBay

8" blast gate | eBay

6" industrial grade cast aluminum blast gate - New

Buy Blast Gate Metal 6in. Self Cleaning at Busy Bee Tools

Self-Cleaning Blast Gates - Lee Valley Tools

Lots of options, I think it will be fine if we do a consolidated order and bounce the shipment.

So far I’ve ordered everything but the gates as I don’t have enough money currently to purchase them.

Almost all of the parts have arrived aside from:

  • Pistons
  • Fittings for the solenoid valves

OK, so i finally finished off a couple of rough 3D models for the main bus of the Dust extraction system.
This one was based on the current extractor location.

I modified it to take into account the building exit location as well as trying to ensure that the main bus pipe doesn’t get too much in the way.

Here is the whole sketchup file if someone wants to modify it or view it better.