Lathe Dust Collection Idea

[BonPacific]

Okay, I may be overthinking this, but I'm looking for some ideas/advice.

Rockler sells their whole Dust Right branded thing, for $50, which is basically a hood on a stand. Reading reviews, it seems to work alright, but is kind of cheaply put together according to some reviewers. A few people complain about not being able to get the hood close enough to the work when turning small or oddly-shaped items, due to mounting directly to the lathe bed. I've definitely run into times where my Jet midi lathe's bed gets crowded on smaller turnings, and I wouldn't have room for this accessory.

So I was thinking, all I really need is an articulated arm, and a dust hood. Checking monoprice, I can get a nicely articulated monitor arm for $22, which would mount directly to the lathe bench, and Powermatic sells a 4"x10" dust hood for $6 on Amazon. So I'm thinking that for <$30 and a few pieces of scrap wood, I can have a sturdy articulated dust hood.

Am I missing something?

[wtnhighlander]

Sounds like a plan to me. Let me know how the monitor arm works out, I may need one for a monitor!

[lewisc]

I've just started using one of these. Good collection across the width but it's a fiddly thing to move into place. You could be on to something with the monitor stand.

[Just Bob]

I bought this :http://www.grizzly.com/search?q=(dust+AND+collection)+OR+(dust+OR+collection)+AND+(category:Attachments) used a muffler u-bolt and stuck it on my banjo.  Kind of ugly, but it works.

[BonPacific]

Well, parts are ordered. I'll post pictures once it's built.

[ChrisG-Canada]

Looking forward to the pics!

[Marmotjr]

I spent $1.50 in hardware for mine, and it works pretty good.  If I wanted better suction I'd use bigger PVC.  I've since shortened the one side of the shield to allow for different placements left to right. 

 

[thatCharlieDude]

I use a Shop Vac with the large rectangle attachment and a clap to hold it in place. I'll try to take a picture tomorrow. It's not very close to the lathe but the suction is enough to overcome the distance. 

[BonPacific]

Okay, here are the pictures. I haven't gotten around to turning anything yet, but I tell ya this thing sucks!

 

The only problem I've found is that the arm would work better if mounted well off to the side, but my makeshift lathe stand doesn't have space for it. The arms move with the perfect amount of force, so I can reposition the head at will, but the weight if the DC hose doesn't pull it around.

[thatCharlieDude]

Nice! That looks a lot better than my cheapo setup

[Mark J]

@BonPacific how is this experiment going?  

 I stole your idea, using a monitor stand I had on hand:

Hasn't worked so well:

The shop vac doesn't generate enough air flow to suck up the debris for as close as I can position the nozzle.  

This particular monitor stand is spring loaded to counter the weight of the monitor, which doesn't help the cause.

I might try some other configurations.  Real DC with 4 inch line would make a difference.  

 

*And yes as a matter of fact I was thinking of taking my lathe to the Antiques Road Show.

[BonPacific]

Mine's working alright. It doesn't catch the big chips from the roughing gouge, but I can watch the smaller dust getting sucked in. It works especially well for sanding since I can angle the paper to throw the dust right towards it. 

A 4" DC is definitely important. I also have mine venting outside, which increases the CFM from my paltry little HF DC.

[Bankstick]

This is timely!  My wife asked about how I collect the chips and dust when turning.  I told her I fire up the Shop Vac when I can't see the tops of my shoes.  Then I break out the wands and floor attachment.  Vacuuming definitely sucks!  BTW, I like the PVC system.

[AndrewPritchard]

I recently decided to build a stand for my mini lathe. It's a bench top model, but if I tried to turn anything that was even remotely unbalanced, it would shake itself off the bench.

So I build one out of some 2x6s and 2x3s (just cos that's what I had).The 2x6s run parallel to the lathe bed. I cut 45 degree bevels in the top, so chips and dust would be guided inbetween them and down into a dust collection chute which is hooked up to my 4" dust collector. I ended up gluing a little bit of the bevel I cut back onto the 2x6 so it would create a flat area at each end so I could bolt the lathe to the stand.

I don't usually have the dust collector on all the time, but if I do there's no build up in the chute. If I don't have it on, I can persuade the chips to slide down the chute by banging on the bottom. A smoother piece of plywood would probably work better, but I'm working with what I got.

I then added a sheet of leather to the front of the lathe, to stop the chips from falling onto my feet. Now probably 90% of the chips fall into the chute to be sucked up by the collector. I used leather because I didn't know if it would interfere with the chisel handles whilst I was turning and wanted it flexible enough that I could brush up against it without it interfering with my tools. Turns out I could have used plywood because there's no interferance at all. I added a couple of concrete blocks to give the stand some weight which has helped enormously with the vibration.

You can't really see the leather on the picture because it's coming straight at the camera edge on. Since taking this picture, I added some casters on hinges so I can wheel it out of the way. The concrete blocks make it way harder to move so the casters were a must.

[Marmotjr]

As far as I can tell, short of having a hurricane powered DC (that's in a tropical storm, not some brand), you're not going to collect the big chips.  Those will fly away and fall to the ground.  You're not worried about those.  You're worried about the fine particles that are staying airborne and being inhaled.  Really, only the particles that can stay aloft in the air are all we care about. 

What @AndrewPritchard has made here is a chip collector and not a Dust collector.  This will collect the chips and shavings that fall down into the chute, but will do very little for air borne dust that does not stray in the direction of the collector.  Mix this system with a well designed dust hood, and you'll have very good system.  A chip collector like this is on my wish list.   But, whenever I am turning, especially with a bowl gouge, the chips tend to peel off and travel down the length of the tool for a little bit before flying off.   So frequently my shavings are not dropping straight down, but coming at me or just by me, and avoiding a chip trough altogether. 

It's the very nature of the work that a lathe can do is what makes it very difficult to design a good DC.  The work pieces just come in too many shapes and sizes, and the machinery does not enclose the cutting area, like a drum sander or planer does. 

Let's stop and think about what a DC system does, at least on the users end of the system.   It creates a negative pressure differential at the end of the hose, as compared to the air around it.   The air nearest the end of the hose will feel this difference more than air some distance away from it.  Because we are talking about just the end of a hose, it creates basically a point source for this negative pressure (and please excuse my crappy illustrations):

 

That's all well and good, but we all know that just pointing the hose towards our work really doesn't do any good.   Because the pressure difference trails off as you get farther from the end of the hose, (I'm assuming it follows the inverse square law, but I have not researched this), it means you have to get the hose very close to your target for it to be effective. 

This is where hoods come into play.  Since the distance traveled to the end of the hose equals a lower pressure, we want to make sure the majority of the air traveling to the hose passes near our work piece.   A hood will create a series of new point sources of low pressure around it's rim, and anything outside the hood will follow the same fall off of pressure as distance increases from the rim.  (If I had the software available, I would model something in 3d with actual calculated pressures, but I don't so I can't)

The shape of the hood now creates a region in space that dictates how the pressures will act.  If we shape the hood to form a circular opening, then the pressures will form a region similar to what is shown in the first pic, it's now just a bigger 'point' source of low pressure.  If the hood is shaped in a square, like a lot of the pics in this thread are, it will create a similar shaped region of low pressure.  This will work great if your work piece fits inside this region of low pressure.  But if it extends outside of this region, then dust particles have a higher chance of escaping when working on the parts outside of the low pressure region.   

So having a variety of hoods available will increase the dust collection your system can do.  If you are turning a pen or spindle, then a shape like I have in my pic will work great.  But for a bowl, my hood works ok but not great.  A hood that encloses the entire shape of the bowl would work best.  For really long spindles, a long narrow hood with multiple hose ports might be necessary.  If you can, having the hood actually conform to the piece is best.  In this photo, you will get similar amounts of suction at the ends of the spindle as you will a few inches above and below the middle.   (I don't like the hose at the upward angle, I think it should be level, but whatever). 

 

 

There are a lot of other effects that come into play with Bernoulli and boundary layers, but that's getting a little nit picky.  Just understand that dust will tend to cling to the rotating body as the boundary layer pulls it along, and not just fly straight off in the path you think it should due to angular momentum, so having a hood that creates equal pressure around the work piece is key.

 

 

Summary, and TLDR:

1) The distance the work piece is from the hood is critical.  The closer the better.

2) The work piece needs to be completely inside the region of low pressure created by the hood.   

3) If possible, 'wrapping' the hood around the work piece, yet not interfering with you or the tools is best. 

 

I love the positional ability of the OP's arm.  It's much easier to adjust than the setup I have.  But having the ability to rotate the hood or switch out for another hood would be key in my opinion. 

 

[Marmotjr]

For some reason it is not letting me edit the post (editor is not loading correctly, it's not a permissions thing). 

Since the distance traveled to the end of the hose equals a lower pressure, we want...

should read as: Since the distance traveled to the end of the hose equals a lower pressure difference, we want...

 

Feel free to pick it apart if you feel it's in error.  I'm not a physicist, but I did sleep in my own bed last night, but I have spent quite a bit of time self teaching myself aero and hydro dynamics in my other hobby building RC racing yachts. 

[Mark J]

@BonPacific I totally stole your idea.  Again.  

My new installation is decidedly less refined than yours, but this version works better than my first.

As expected dust collection when sanding is most, but not all.  Chip collection when turning is next to not at all.  

Hopefully this will mean a lot less dust coating everything else in the shop from the sump pump to the scap wood.  So thanks for sharing your monitor arm idea.

Now that I have a proper 3 HP dust collector the next problem I have to solve is noise.  The thing is just flat out loud.  Way loud.

Without hearing protection it is surprisingly wearing to put up with the noise.  With ear plugs the noise is controlled, but I find I then can't hear the turning tool on the wood which is an important sensory input as to how the cut is going.  Ear muffs are in between, but for some reason hurt my ears after an hour.

[Marmotjr]

You sir, have way too much uncluttered space in that shop. 

Another option is to unbolt that stand from it's clamp base, and bolt it onto a slider that fits onto the ways of the lathe....

[Mark J]

I had had to clear out the shop to do some work on the basement.  The picture was taken as I moved things back into place.  So I wish it were that uncluttered now.