Interest in upgrading dust collectors?

Our setup isn’t that big - I think there’s an argument for using proper spiral steel dust collection pipe and fittings instead of PVC. All the fittings we’d need would be pretty typical for dust collection applications, and grounding the system would be trivial.

I also suspect the fire marshall might have a thing or two to say about using plastic ducting to manage combustible dust?

Confirmed. NFPA 664 Woodworking facilities. Not sure if Austin has adopted this code specifically, but it seems like a good idea.
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If we start on the first DC, and get a cyclone and barrel attached, with a sensor, that works be a huge step. We can then plan out the ducting.

I’ll be there Saturday and Sunday afternoon. @Jon or @dannym , of your going to be there, is be glad to talk about it more in person. It sounds like quite a bit of thought had gone into it already. Maybe we can start pulling the pieces together?

Agreed. Upgrading the collector and upgrading the ducting are different projects.

I’m interested in this project but I won’t be available for group projects until mid-October; I’m quarantining, then out of town for a while. Don’t hold up on my account, but if there’s still work to be done when I get back I’ll be around to help finish up.

not hard electricians do bend it all the time

The sanding table needs to be connected. Currently the area is not usable. I had set it up with a special compatible vac that was small enough to work with the available power (barely) on a single circuit. It got replaced with a bigger shop vac that routinely overloads the breaker, so it’s not usable or safe like this. Plumbing it into the DC is a good answer.

Oh, righto. I forgot about the sanding table. Some of those machines have pretty small dust ports - can a conventional dust collector generate enough static pressure for them, or should we be looking at something customized or a Supercell ?

The list grows. The sanding station is at least next to the DC we’d like to upgrade first, or make the basis of a central system. It still starts with adding a separator and improved filtration. I’d be happy to organize the list of air quality issues / upgrades. If there are any other ideas, suggestions, let’s get them on a list. For example, an overall filtration system would also be nice, but little point if we have not upgraded the dust collection.

From the conversation up to now, it sounds like Danny has a good idea (with a working build) on a vortex system, with some kinks to iron out. And the filtration bag. Implement those changes, with a manifold (?) for extending the system in the future. We can’t try to boil the ocean, or we’ll never get started.

One thing to think about up front is the size of the barrel. If it is to become a central system, a smaller barrel will need frequent changes. Larger barrels are tough to lift into the dumpster.

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I’m not convinced one system to rule them all is the way we want to go. I’ve been doing some window-shopping on the topic, and we’d be looking at 5000+CFM to cover all the machines (see link below for my numbers).

That’s 10HP dust collector territory, and I’ve been gathering that motors of such size can be idiosyncratic regarding things like minimum run or idle times that might not play nicely with the tool-based dynamic control. We’re not a production shop, so I don’t think we want to pay to keep a monster dust collector running full time. Definitely interested in hearing from anyone with experience in such things.

The central alternative would be automatic blast gates like Danny suggested earlier, with a DC sized to support up to some number of machines operating concurrently. Duct design and gate programming to maintain minimum run velocity (required to keep sawdust moving) regardless of gate demand can be tricky, but it’s not impossible.

Door #C is dust collector islands, or basically what we’re doing now. This keeps motors smaller and runs shorter, at the cost of floor space and more bins to empty. The iVAC control system supports up to 4 independent dust collectors, so we have plenty of room to improve automation. This route would mean individual upgrades would be projects of more manageable size, and would minimize the impact of a collector failing or going offline. There’s still a lot of work to do to improve ducting and wiring, but this feels more our speed to me.

You need blast gates for sure. The physical size, electrical requirements, and deafening, droning noise of such a massive system isn’t what we need.

You are correct about minimum flow velocities. That actually can be a tricky situation to keep chips entrained, while keeping flow resistance low. Sanding dust is easy, but like the table saw and planer make heavy chips and debris.

A long run of 4" pipe creates excessive flow resistance that may make for poor flow no matter how powerful the DC is.

But 4" is the max size for a lift pipe from a chip source with a 4" port. More and the CFMs may be better, but the velocity is too slow to blow chips upwards.

A 4" horizontal run is probably too much resistance for even one tool over distance, and definitely too much resistance if multiple branched tools are turned on.

But the difficulty is that 6" pipe is only 45% of the velocity. That can actually be too SLOW for a single tool producing chips, if only a single 4" port is feeding it. In some cases you may need to hook it up so 2 ports on a leg open together so there’s adequate flow velocity through the 6" pipe.

Now a table saw, you can- and probably have to- put a crap trap inline can because sometimes you get like 3"-6" strips of wood through the port that cannot flow and just block the pipe. There’s a grill on the miter station. But a planer and the CNC produce crazy stuff. Big chips, the CNC sometimes makes long plastic strings. Trapping it with a small can sounds impractical because that can be literally all the output of a planer, not just odd, rare chunks. Cubic feet of chips are what it does.

So there is one hybrid solution- to avoid multiple dust collectors (which come with additional electrical requirements) and filters, you can set it up so there’s like a 22 gal trash can collector by the planer to collect the heavy debris, but no dust collector motor/filter there. It runs large dia, low resistance pipe that runs at low velocity, low resistance, but high CFM to the DC, cyclone, and filter. Then you only have dust in the line, not heavy chips, and you get high CFM but nothing stuck in the system despite the low air velocity.

My main concern about a centralized system with gates is the outcome/management of concurrent tool use.

Let’s say we have 6" runs to pairs of tools. That means if one tool is in use, collection to both tools must be open to maintain run velocity. Even with covid restrictions, I don’t think it’s unreasonable that somebody might be using the planer while somebody else uses the table saw while somebody else uses the CNC. That’s three separate 6" runs, so we’ll need to move ~2400CFM to keep all the debris moving.

That’s basically a 5hp collector. That still sounds big to me, but maybe it’s reasonable?

https://www.grizzly.com/products/Grizzly-5-HP-Cyclone-Dust-Collector/G0442

What happens if somebody then starts using a bandsaw and opens another gate? Duct velocities fall, and crap perhaps starts accumulating in the runs. Then when the bandsaw turns off and that gate closes, run velocity picks up and all that crap slams into the impeller all at once. un-amazing things can happen quickly.

It’d be possible to set up tool interlocks based on dust collector capacity, but I guess it comes around to how idiot-proof do we need to make the system?

There are a lot of pieces to this, and clearly the entire woodshop could benefit from improved DC. The air in the shop is pretty bad, right now. Does upgrading the DC on the tablesaw/ miter saw now limit the path to a larger central system?

Not unless you’ll be offended if stuff gets switched around later :slight_smile:

100% fix the immediate problem without waiting for a grand plan. Get enough nerds together and we can argue forever about the best way to do something.

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Back to the start again, then. How about we upgrade the DC by the table saw with a separator, and improved filtration? Then we can start the larger discussion of a long term filtration strategy.

We don’t have electrical to run a 10 hp central DC. We need DC islands as mentioned above.

I think we need to add a vortex(s) to the table and miter saw dc. It would spare the filter bag a bit of the fine dust.

Thanks @cfstaley , yep that’s good with me. go ahead and pick out the pieces and send me the links etc. and I will order it.

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Just chiming in to physically help with ductwork in the shop once parts/decisions are made!

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@EricP

Here is the link to the Grizzly cyclone attachment. It has a 6" inlet with a Y adapter to 2x 4" feeds. Our current DC is a 6" inlet, with 2 x 4" feeds coming in. One from the table saw, one from the miter saw. Drop dead simple. It can go inline on the current system. We can upgrade the bag later. We can upgrade / modify the feeds from the saws later.
Two options here. Amazon, which is $54 more, but free shipping, though that doesn’t include tax. Shipping through Grizzly is $22, then plus tax, it’s $348.78, so that looks like the way to go.

https://www.grizzly.com/products/Grizzly-Grizzly-Growler-Cyclone-Separator/G0863

Here is the IVAC dust sensor. This can be attached to the drum. It’s half the price of the Oneida system, and will give us a reminder that can be seen across the shop.

The sensor is a nice to have. The Grizzly barrel does have a view window.

I will not be in the shop next week, but I will be there the week after. I can install it then, though as easy as it should be, just about anyone could do it. Either way, I’d be glad to do it.

Thank you for posting @cfstaley. I think that this is a good unit to help us reduce the chip load. The wheels will help members matriculate the unit to dump it.