Dust collection system

[DixieReb31]

Thinking about installing a dust collection system for my LT35HD.  Any recommendations as to how to build one?  Will a standard dust collector for woodworking work?

[DanMc]

I have a Grizzly 2hp dust collector, but that's down in my basement wood shop, not on the mill.  2 hp would be enough power, but I would recommend a cyclone filter on top of a large container on a pallet that can be moved by machine and emptied.  Damp sawdust is heavy, and the bag with the Grizzly collector would fill up pretty quick.  Also, if you don't empty it regularly, the cloth bag would rot out.    

[SawyerTed]

Jake @customsawyer has a system and so does Robert @YellowHammer as I am sure there are others.  Both these guys have theirs connected to their mill and other machines as well.  

[Don P]

Do you need to collect it or can you just blow it into a pile? Mine is just a blower, I move the pile with a skidsteer.

[DixieReb31]

I don't "need" to collect it. Just looking for a way to stop shoveling it all up. 

[Don P]

That was my need. I just have the blower for a dust system sucking and throwing it out beyond the mill in a pile, no bags or cyclone just a fan and some pipe.

[Old Greenhorn]

I have been watching this since you posted hoping to hear some neat ideas. "We" have an ongoing debate on this subject. Bill (the mill owner) and I (the sawyer who runs it) have differing opinions on how to improve our dust issue. Bill wants to tie in a 4" flax hose along the live chain (outboard) to follow the mill with the blower at the far end. I am thinking it will be another 'thing' to get hung up or hooked onto something, or snag. I would prefer to go overhead if we have to attach to the mill and have a cable setup for the looped hose. My actual preference is to just let the dust land and set the blower up with a long hose and use it like a vacuum at the end of each session. I'd like to blow it into a big stationary box with the floor about 4' off the deck and a discharge chute. We bag and sell the sawdust to folks with chickens, us it for oil-dri, and other stuff. So having a way to fill bags would be very useful. We have the blower, but keep debating the approach. I should just build the dang box to get things moving. we need that either way.
 I'll be interested to see what you come up with and any other idea that come out.

[caveman]

We have a 120v blower hooked to the mill with 20' of 4" flex hose.  The blower is mounted above, about mid-way along the outfeed side.  From the blower, the sawdust moves overhead through a 4' pvc drain pipe and dumps on the ground.  It gets clogged sometimes when sawing wet cypress but it is a huge improvement over shoveling sawdust every few hours.  

If we had 220 volts to the mill shed, I'd install a bigger blower.

[D6c]

I just finished installing a 5hp blower I got from Woodmaster.
Woodmaster Dust Collection

I put it up high on the wall and mounted a dust cyclone below it that drops the sawdust into a55 gal cardboard barrel.  The blower exhausts through the wall to outside.  It could just as easily be setup to blow the dust outside and not use the cyclone.  
The mill is about 40' from the blower, piped with 6" furnace pipe and 6" urethane flex hose down to the mill.
So far it's working great.  The only dust I get on the mill is the small amount that gets deflected off the guide roller.  Way better than before....no more pile on the floor to shovel and much less dust flying around getting I my eyes.  I still wear a dust mask but I'm especially sensitive to dust.
If I get to sawing a lot more, may do away with the cyclone and blow it out into a wagon.

[YellowHammer]

I've tried several, the easiest is a 5 hp trash blower hooked up to the mill sawdust chute with a 6 inch flex pipe and then a straight pipe out the blower with a downturn elbow to spray the sawdust down into a pile that can be cleaned up with a loader bucket.  It will catch 95% of what comes out of the mill and you'll never go back to  hours of shoveling.

Or go further and get more hp, get a cyclone with airlock, and mine will put the sawdust directly into a big dumpster hopper.  It's easy to generate several tons of sawdust a day, and it can be shoveled by hand everyday, or a blower can do it with nearly zero effort.  

It's an easy call.  Spend a grand$ and sell the sawdust shovel, or shovel a few thousand pounds of kitty litter by hand every day.  

[customsawyer]

I started with a small blower from Timber King. I think it was around 3hp but can't remember for sure. It didn't do to bad but it did leave a little bit to be desired.  When I added the planers I needed something with a lot more CFM. Just be careful running your discharge through PVC as I have heard that sawdust can generate static that can cause a fire. I've never personally seen this and know of a few mills that have run PVC and never had a problem. I don't know if they added grounding wires or what to control the static.

[alecs]

A simple solution I learned from Jim Rogers a long time ago is to attach a large bucket to the mill discharge chute and then empty it periodically.   I tried a mock-up of this on my mill and it works to collect most of the dust.  I took a second bucket and cut it up as a "cap" for the main bucket to improve the capture rate.  I used one of those 3M sticky tape hooks to attach to the mill at least until I am sure about the mounting location.  Will add a picture in a bit.

You do have to empty the bucket fairly often and it doesn't collect all the dust, but it's better than shoveling, and super cheap to implement.

I have a cyclone dust collector with a sealed box for my indoor shop equipment but I think something like that would fill up really fast too, and also have the problems of clogged hoses and filters, especially with wet sawdust.  What about using a truck loader like landscapers use for leaf pickup?

[Don P]

 A friend uses one of the tow behind lawn vacs. Basically a small trailer box with a gas powered ~12" radial blower, not really any different than a dust system without a cyclone. The other name for a radial blower is material handling fan, lots of applications. They are straight vaned very simple fans so that they self clean but this makes them less efficient and noisy compared to something like an inclined vane squirrel cage air handler of the same size, which will clog instantly if used for real material handling. The chips get blown in the trailer. the air lifts the vents on the top. It captures the majority of the dust in the trailer.

[PoginyHill]

A cyclone with no bag attached or even no rotary airlock valve would do the trick, I think. A bit neater than simply blowing into a pile, but less expensive than a fully enclosed system and maintenance free. There'd be some air coming out the bottom with the sawdust, but most should escape through the top. Could empty into a dumpster or enclosed area to make it easy to remove with a tractor bucket.

[Old Greenhorn]

A simple solution I learned from Jim Rogers a long time ago is to attach a large bucket to the mill discharge chute and then empty it periodically.  .......

That worked for me on the manual mill until the head got close to the ground. But on a larger mill cranking out lumber it's not practical. On the LT50 I would have to empty that bucket twice on each pass doing 16' x 24" logs. :D

[alecs]

Alright, here's another idea.

Along the backside of the mill, make a trough of sorts with a horizontal belt conveyor at the bottom.  Same kind of conveyor used for firewood processors or other bulk handling, etc.

This would feed to another conveyor that would be inclined up to a trailer, dump truck, or wherever the sawdust will ultimately go.  Control the conveyor so that it only advances when the saw is retracting.  So the saw spits a linear pile of dust onto the stationary conveyor when the cut is being made, and then the conveyor advances.  If it were powered off the mill by a hydraulic motor, the conveyor wouldn't be competing for power while the mill is going forward and making a cut.  No filters, no 50 hp+ blowers, no three phase wiring, very little noise.

Found this picture as an example of what I am thinking of.


 

Sorry, did I overcomplicate it?  Did I mention I am an engineer?   :D

And here is a picture of my mocked up bucket with "cap" to catch dust.  Yes, it works for a small manual mill.  Agree that it would be completely impractical for a large automated mill doing big cuts. As it is, have to empty it every two or three passes.