Last year I bought myself a serious dust extractor for use in the workshop. It has a huge dust collection bag and a 100mm hose.I have it sat between my bandsaw and my lathe. The bandsaw has a specific dust port for connecting this type of extractor to which makes life easy. The lathe on the other hand is not so easy.
Basically I set it up with some garden wire providing a wire loop hanging off the bed bars, which I could hang the hose end in, which left it pointing vaguely where I was working. Whilst this seems fairly rubbish, the extractor is powerful enough that it was still effective at sucking up all the dust from sanding etc.
Although it has been effective, it was not really a satisfactory solution. The hose gets in the way, and often wound up not really pointing where I wanted it.
I looked around for ideas for dust collection hoods that would provide a more sophisticated solution. I found generic dust hoods for connection to 100mm hoses, but they seem to be fairly expensive for a shaped bit of plastic, which I'd still need to mount in something.
Having not really found anything that was quite what I wanted, and certainly nothing in a 'sensible' price range. I decided to make my own.
So I hunted around my garage to look at what I had that might work as materials for this project. I quickly found a piece of plywood, about 5mm that looked like it would fit the bill. I also had a suitable size stick of something like pine, that was already planed and squared that looked good for a support baton which would get bolted to the bed bars.
The top of the plywood already had a big circle cut out from a previous project, and I decided that I could use that arc cut out of the headstock end, and just cut another section to the same dimensions for the other end. It has to be said I didn't really bother to stop and figure out dimensions. I probably should of, but I basically went on what looked right, and I could keep sizing things up against the lathe to get a good idea.
Once again I really appreciated my bandsaw for making this project pretty trivial, it was very quick to cut up sections to size. Once I had the two end sections I decided to cut an angle on what would be the back top corner. And rather than measure to get it right on both ends, I just cut them both at once. For an exact match.
Then I just set the fence width to match the length from bottom corner to the corner of the diagonal cut, in order to cut the width of board for the back, and similarly set the fence for the angled top section. At this point I'd not settled on how wide I'd make the whole assembly, I basically set the ends on the lath to get a reasonable idea of what I wanted, and just cut both the back and top boards to match.
The idea was to just nail the left hand side to the pine stick which would have a channel drilled out so that it could be bolted to the bed bars just like my tool rest. Again I didn't really measure, I just set it against the lathe to get an idea for how long to make the channel to get the range of movement I wanted.
I cut another piece of the pine to the same length for the right hand panel to nail to, and decided I'd just connect the rest with hot melt glue. Since it would be fast.
First things first I needed to cut out a channel in the right hand side that would allow my live centre tail stock to pass through, in this way I should be able to set the hood over at least the end of what ever I work on. If I have to work on something long enough that this end needs to be as wide open as the left hand side, I may adjust it then. For the moment I'd rather keep it as enclosed as possible,
This picture just showed me sizing it up against the tailstock to make sure everything was going to fit.
So now for the more complicated bit. Obviously I need some way for the hose to attached to this contraption. My idea was to make a ring that I would glue to the back board, which the hose would fit snugly over. For this I found myself a piece of MDF glued up to a block thickness that would give enough purchase for the end of the hose. Basically my hose has a few plastic guards that form a cross in the hoseway to stop big items getting sucked into the mechanism. These where set about an inch and a half back from the end of the hose, so I got a block of mdf about that thick to give it maximum interlocking space. As it happened I had a lump of MDF laying around already glued into a block of just the right size. So I didn't need to wait for any glue to dry. ( This is why I don't throw anything away!)
Having got the block, I mounted it on the lath and turned it down to the correct diameter.
Here I'm checking it against the hose itself, you can see the plastic guards I was talking about.
Now all I had to do was hollow through it to form a ring. I wanted to leave enough wood to make it a pretty solid ring. I would after all be connecting and disconnecting the hose as I use it with other machines, so I want it to survive. But at the same time I'm conscious of the fact that these kinds of extractors are not designed to have their airways reduced. They lose suction, since it's more about high volume of air, not high pressure of air. Which is the main difference between one of these and a regular 'vac' Anyhow I once again settled on a 'by eye' feel for what would work and set to hollowing
And once I was happy with the ring shape, I parted it off and was left with a nice neat MDF ring of just the right size.
With the ring formed I placed it roughly where I wanted it on the backboard, and drew a circle for it's internal diameter. Which I then needed to cut out of the board. For this I decided to just use my drill press to drill a bunch of holes all the way round the circle, then just use a chisel to cut the connecting bits
This wasn't terribly neat, but it was fast and easy. I just couldn't be bothered to get my jigsaw out, even though it might have made a neater hole. I just used a bit of rough sandpaper to smooth the worse of the rough edges and plowed on.
I glued the ring in place at around this hole. I had actually tapered the ring slightly so that the fit on the hose would get tighter as it went over, So I was careful at this stage to glue the wider edge to the board.
With that clamped in place, I decided I was too impatient to really wait several hours for the wood glue to dry, so I got out my hot melt glue gun and set it warming up.
This is the first time I've really used my glue gun for a project like this. I've read variously of them being used to form quick glue chucks which can then be re-heated to remove later, and so I figured it would be easily strong enough for my needs.
I added a little hot glue around the ring against the board. And let it dry whilst I got together the other panels.
Hot melt glue made this bit really fast and easy, just run a line of glue along the joins and hold for a few seconds before moving on. And before you know it, you've got a dust extractor hood!
I think it's taken me almost as long to write about this as it took me to get this far actually making it. It really was very quick to put together. And I was keen to put it in place and have a go. I had ummed and ahhed about putting a 'floor' in place, vs just leaving it open. In the end I decided to cut a panel to size, but not glue it in initially to see how I got on.
This is it in place, it only gets bolted on the left hand side, the right hand is just resting on the bed bars.
Next I attached the hose to the back, which was a bit fiddly because it's quite a tight space, and the host isn't all that flexible for tight 90 degree bends.
With everything in place I decided it was time to give it a whirl. And so I switched everything on and attempted to sand the piece of mdf still on the lathe. This worked great! I could just make out a steady stream of fine mdf dust going straight into the extractor. Wanting a more visually obvious demonstration I decided I'd just a tool to see how it handled larger bits being cut off.
At this point I discovered the first thing I'd not taken into account. I went to move the tool rest into place, and realised it hit the bottom of the back board. So I couldn't get the tool rest in position properly. I was now glad I had not glued the 'floor' in place, and the adjustments became obvious. Cut a section out of the bottom of the back board, big enough to allow the tool rest clearance to move around. Then set the 'floor' at an angle up towards the hole.
Some quick adjustments later and I ended up with what is now a finished extractor hood.
I've now had it in use a few times, and love it. It does a great job of sucking up a lot of the debris coming off the lathe. Obviously the large chunks tend to go all over, but mostly it's the dust and finer pieces I'm interested in capturing, and it does this without the hose getting in my way.
The couple of issues I have is that it's a bit slow to attached and remove, and since it only bolts on one side, the hose occasionally pulls it enough to twist the whole thing. I'm not sure if I will do something about that or just live with it. If I add another bolt it will just get even slower to setup and take down.
Generally this was a great little project. Very quick to put together and very cheap, given I used materials I already had laying around as effectively scrap. And I hope that it will help my dust extractor be even more effective when I'm using the lathe, which can only be a good thing.