 In my last video I showed you how I made this mini cyclone dust collector from an old shop bag. And in this video I'm going to show you how I'm going to use it to supercharge my main big dust collector by hooking this one up to that one. Let me show you what I mean. On my table saw I've got it hooked up to my main dust collector through a 4 inch line which hooks to the bottom of the cabinet. And that goes up the wall and across the ceiling and then back down the wall behind the bandsaw and then it hooks up to the main dust collector. And that does a pretty good job at collecting the dust that goes from the blade into the cabinet. There's still some dust though that gets shot off from the top of the blade when making cuts and thrown into the air and in the front. And to capture that dust I designed and built this. This overarm dust collector does a really good job at collecting the rest of the dust that's thrown above the blade and otherwise into the air. With the design of this overarm dust collector it's got a very small dust chamber and it's hooked up to a pretty small dust hose. And that paired with a shot vac makes for a really good dust collection. The only downside with this setup is that I've always got to have my shot vac hooked up to the overarm dust collector. And that means it's always out, always on the floor, the hose is out and the cord is out and they're always just getting in the way. The next logical thing to do is to connect the overarm dust collector right into the main line through a T and another blast gate up there. And just have the main dust collector collect the dust and that way I don't have to have the extra shot vac hooked up. The problem with this setup though is there really just isn't that much suction right where I need it. My big dust collector is what you would call a high volume low pressure dust collector. And by the time the air goes through that 4 inch pipe gets reduced down to the smaller pipe there really isn't a whole lot of air flow left and the pressure was low to begin with. And that just doesn't leave a whole lot of suction right here at the blade. And that's why I made this, a dedicated high pressure high suction machine just for my overarm dust collector. It's nice and small. It's got a mount on the back so that I can screw it to the wall so it's up and out of the way. It's pretty easy to empty the collection bucket. It's got a cyclone chamber to help separate the big chips and the fine dust goes out through the top and since it's made from an old shop vac it's got a ton of suction. Now I could have just added a filter box to the exhaust of this cyclone and then mounted it to the wall and I would have a pretty sweet dust collector for the overarm. But then I got to thinking I've already got a pretty nice filter on my main dust collector. Could I just hook the exhaust from my mini cyclone right into the dust collection line of my main dust collector and have it suck out the fine dust? Then I wouldn't have to deal with a separate filter box for this unit and my main one could do all of the work. So I've got the dust hood hooked up to the mini cyclone and the exhaust on the mini cyclone is now plumbed in through a blast gate into the main line to the main dust collector which is behind the camera. And so what do you think is going to happen? Is the big dust collector going to out suck the little dust collector and cause it to run away and burn up? Or is the mini cyclone going to pump so much air into the big dust collector that the big dust collector is going to run away or its suction somehow is going to be diminished? Let's test it out. The first thing I'm going to do is just turn both systems on and see what happens. So open the blast gate for the main dust collector and open the blast gate for the mini dust collector. And then I've got a remote for each one. So I'll turn on the main dust collector first. So both dust collectors sounded just fine. It didn't sound like one was outrunning the other. The suction at the overarm was really good. Much improved over just running it through the main dust collector line. The four inch hose down here still felt pretty good. It was maybe slightly less than before. Kind of hard to tell but seemed adequate. I've got two tools to help measure the actual performance to see if there is a difference. I've got this anemometer to measure airflow or CFMs of each dust collector and a couple of adapter plates to adapt to each hose size. And then I've got a homemade anemometer which will measure inches of water lift or the static pressure of each system. So I'm going to start by measuring each dust collector individually. And so I will shut the blast gate for the mini dust collector and test just the main dust collector first. And I'll test it at the joint down here. To take measurements for the mini dust collector I've got its blast gate open to the main line. And so it will be exhausting through that main filter. The table saw port is taped off and that just allows the exhaust from the mini dust collector to go through the filter instead of escaping out there. And then the intake hose for the mini dust collector I have upsized it to the same 4 inch line so that the readings will be comparable. For the last set of measurements I've taken the tape off of the table saw port and both blast gates are open. And I'm going to turn on both the main dust collector and the mini dust collector. And I'll take readings at both ports and see if the values have changed. So what did we learn from that testing? Well we confirmed that the main big dust collector is a high volume but pretty low pressure dust collector. And we also confirmed that the mini dust collector is a very high pressure but pretty low volume dust collector. We also learned that the mini dust collector when it's hooked up to the big dust collector maintains essentially the same airflow at the nozzle. But the pressure went up slightly I guess due to the additive pressure from the big dust collector as it's sucking on the little dust collector. What was interesting is that the airflow to the table saw underneath actually went down a little when the mini dust collector was hooked up. And if you think about it that makes a lot of sense. Essentially the main dust collector has an impeller on it that's designed to move a certain amount of air. And when additional air is introduced into the system by the mini dust collector well it can't really suck any more air than it's designed to suck. And so that means the other input here can't suck as much air as it used to now that there's more air being dumped into the line up here. And that value was essentially subtractive. The amount of airflow at the bottom of the table saw decreased by the amount of airflow that was being generated by the mini dust collector. But since the mini dust collector is a high pressure but low volume system I'm gaining a ton of pressure or supercharging my main dust collector without sacrificing too much airflow from the rest of the system. I'm really happy how this experiment turned out. I can't wait to put it to some more use and see how it performs long term. If you're interested you can watch how I built the mini dust collector in my previous video. Or if you want to build one of these over armed table saw dust collectors for your saw there's a very detailed set of plans available on my website which you can use to follow along and build one for yourself. Thanks for watching, see you in the next one.