Bandsaw Dust Collection Improvement

[Jimmy Harris]

My 17" Grizzly bandsaw makes a lot of dust, but I have no room for a proper dust collector. So, I bought a 1hp portable dust collector, the kind with just a bag attached, and had to remove the roller base, because I couldn't even fit it in the garage with the roller base. Anyway, it's listed at 500 CFM, and might do a fraction of that. So it's not a good dust collector. But I came up with an idea that makes the dust collector get almost all of the dust that falls below the table. And the best part is, it's cheap, easy, and quick to do.

What I did, was sealed off the lower cabinet. I used window rubber insulating strips and a rubber door sweep. I put the rubber window insulation around the cabinet doors, and the door sweep, cut into parts, around the bottom of the little triangle on the top dust collection port and around the blade gap, cutting out a groove for the blade to nest into so it won't touch the door sweep. Now, here's the kicker. I didn't insulate the bottom of the cabinet, nor the top around the top port triangle. But all other walls are sealed. That forces the lower port to replenish the air it sucks out from the gap at the bottom of the cabinet, and forces the top port to replenish it's air from above, where the lower guides are just below the table. This way, you're directing the air flow to where the dust actually builds up, and not wasting vacuum on areas where there is no dust. I've seen videos of people making enclosures under the table and running a third dust collector hose or shop vac there, and so far, this method seems to give pretty similar, and sometimes better, results than a lot of the videos show, depending on their actual method.

It does nothing for the dust above the table, of course. So there's still some cleanup to do. And a tiny amount of dust still builds up around the trunnion.

Now, I haven't tried every type of wood or situation. I'm not claiming it to be a perfect solution. But it works much better than I thought it would. So, I figured it would be worth passing on my findings so others could give it a try and see if it's a worthy modification for them as well.

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[John TenEyck]

Sounds interesting. Do you have any photos to share? Thanks.

John

[Jimmy Harris]

Sounds interesting. Do you have any photos to share? Thanks.

John

I'll post some tomorrow.

Edit: or today, since another reason to back the car out of the garage popped up.

[Edward Weber]

I have a few rules that I follow when it comes to dust collection.
If you can't get it at the source, keep it contained as much as possible and don't fight gravity.
A small bag type dust collector will do a decent job co controlling dust on that saw although I don't know if it will capture enough just using the upper port. Hopefully you'll let us know how it's working for you.

[Derek Cohen]

Jimmy, did you record before- and after results?

The mod I added to my Hammer N4400 came from Rob Cosman, and was a simple PVC pipe under the blade ...



The cap at the end of the pipe was later removed to improve air flow.

The before photo, following cutting several short lengths of MDF looked like this ...





After the pipe was added, it was like this ...





It improved further when the pipe cap was removed.

The dust collection from the pipe was linked to the main hose (which did much less on its own!) ...





Regards from Perth

Derek

[Jimmy Harris]

No, I didn't record before and after results. I wasn't really planning to document it. And I didn't want to measure sawdust or anything. I figured if it wasn't an obvious upgrade that was easily apparent to the naked eye, then what's the point? Plus, running tests and documenting them seemed like a waste of time and wood that would be better spent elsewhere. I have no desire to become a content creator. To be honest, I didn't think it would do that much or be an endpoint for me. And I still haven't done a ton of cutting with the setup, so I can't really say that it won't get overloaded if I go to resaw a wide board or whatever. It was just one of those mods that seemed obvious to me, so I moved forward with it without thinking much of it, gave it a test, and was really surprised with how much better it worked than I had expected.

I say, give it a try if you're curious. You can get a roll of the thin window weather stripping (you don't need the thick stuff or anything fancy) for around $5 (here in the U.S.) at the big box store. Ten minutes to clean and apply the seal. And if you hate it, it's easy enough to undo. I won't guarantee that that's all you need and it fixes everything, but for the extremely limited investment involved, I fully believe it's worth it.

[glenn bradley]

Great improvement Jimmy. Like you I too gather under the table and close off the stock lower collection point.
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I use the stock below the table point and added a shroud that serves as Derek's pipe solution does. Collection is great.
BS-DC-Under-Table-Status (3).jpg
The Cisco logo thingy is just a piece of sheet magnet to block the lower port.

[Edward Weber]

The only issue I would have with some of the solutions like Derek and Glenn shared, is that you need to remove them if you ever tilt the table. Hopefully this is not a hassle.
Thanks for showing the photos

[John TenEyck]

The only issue I would have with some of the solutions like Derek and Glenn shared, is that you need to remove them if you ever tilt the table. Hopefully this is not a hassle.
Thanks for showing the photos

That's the same thought I had.

Bandsaws need a surprising amount of CFM to capture the sawdust when resawing. The solutions above work, to a degree, but the two 4" ports on my Grizzly work fine as long as it have enough air pulling through them. It didn't when I first hooked up the saw and I got dust piling up everywhere, even in the upper wheel housing. That cascaded a whole study of why I didn't have enough flow from my 1200 CFM DC and eventually led to a redesign of my system. I didn't need to buy anything, but I had to reconfigure it to reduce the static pressure losses I was getting between the saw and the exhaust port. Once I did that the saw remains sawdust free even after extensive resawing of 12"+ thick stock. 4" diameter ports will carry about 400 CFM, IIRC, which means 800 CFM for the 2 ports. It doesn't take much static pressure loss to make a 1200 CFM DC drop below 800 CFM. At 500 CFM, and likely less, Jimmy made the right call to try to reduce the airflow required. That works as long as the airflow is properly directed, and the CFM is still high enough to carry away the sawdust. At some point, however, it won't be able to keep up, which may or not be a problem for him, it just depends upon how he uses it.

John

[Jimmy Harris]

That's the same thought I had.

Bandsaws need a surprising amount of CFM to capture the sawdust when resawing. The solutions above work, to a degree, but the two 4" ports on my Grizzly work fine as long as it have enough air pulling through them. It didn't when I first hooked up the saw and I got dust piling up everywhere, even in the upper wheel housing. That cascaded a whole study of why I didn't have enough flow from my 1200 CFM DC and eventually led to a redesign of my system. I didn't need to buy anything, but I had to reconfigure it to reduce the static pressure losses I was getting between the saw and the exhaust port. Once I did that the saw remains sawdust free even after extensive resawing of 12"+ thick stock. 4" diameter ports will carry about 400 CFM, IIRC, which means 800 CFM for the 2 ports. It doesn't take much static pressure loss to make a 1200 CFM DC drop below 800 CFM. At 500 CFM, and likely less, Jimmy made the right call to try to reduce the airflow required. That works as long as the airflow is properly directed, and the CFM is still high enough to carry away the sawdust. At some point, however, it won't be able to keep up, which may or not be a problem for him, it just depends upon how he uses it.

John

Yeah, I did a bunch of research and pulled a lot of ideas from all of the things you guys had posted over the years. I was considering putting a cover, at least partially, over the lower port like you had done, to increase pressure on the top port. But so far, I haven't needed it. Honestly, reducing the amount of free air available to the lower port with the seals probably was enough to keep sufficient power diverted to the top port. And it doubled as a way to keep the airflow directed.

I will say it probably helps that I have less than 10' of flex hose in the total system, so I'm not getting much loss there. And the collection bag is made of felt and probably doesn't filter much. But, I have it placed just outside the garage when in use, so it can blow all of the fine dust it wants into the outside air. So it passes a lot of air.

[Louis Joyce]

Hi John - apologies for the off topic reply, but whilst I too am looking for better dust collection for my Laguna 14/12, I saw you post in another forum a design for a saw blade tensioner, but following the link you left, it comes up with an error. Do you still have that design?

Thanks in advance.

[John TenEyck]

Hi John - apologies for the off topic reply, but whilst I too am looking for better dust collection for my Laguna 14/12, I saw you post in another forum a design for a saw blade tensioner, but following the link you left, it comes up with an error. Do you still have that design?

Thanks in advance.

Try this link Louis. It should work, but let me know if it doesn't so I can figure out why. https://sites.google.com/view/jteney...ter?authuser=1

John

[Louis Joyce]

Try this link Louis. It should work, but let me know if it doesn't so I can figure out why. https://sites.google.com/view/jteney...ter?authuser=1

John

That works - thank you John! Appreciated!