Considering that I am planning to make a few instruments (or at least a good amount of dust) this year, I have decided to invest in some dust extraction. I cannot justify the cash required for a large machine, so I decided to buy a powerful chip extractor and build a cyclone filter system which should filter down to 2-4 micron particles of dust - the chip extractor alone would only extract down to 12-14 microns, so MDF and all fine dust goes through and is still in the air.
The chip extractor is induction motor powered, and is an impeller design which kicks out 1000 cubic metres/hour (573CFM). This is pretty good for my purposes - 400CFM is recommended for bandsawing, and similar for bench-sawing. These are about the most demanding.
It is recommended not to reduce below 35mm on these systems otherwise the impeller just generates drag. I am using 100mm for most of the work and for the smaller tools I am reducing to 40mm or thereabouts.
I looked at a few cyclone home builds online - a google will turn up lots of these in all wonderful various sizes and designs. Ok, some are pretty terrible designs, but hey - you have to give it to people trying.
Here are 2 links:
The first shows a simple design which is pretty functional and effective, the second is fine for hoover-based stuff, though it will never handle more than light dust. there are a bunch of very cool builds showing sheet metal construction in much larger scales - I can't find this right now. Anyway, the principle is simple, so I started into it the same way I like to bake and cook - with no plans - just an idea of what I want the end product to be. Ok, I planned a little, but all in my head last night.
My cyclone chamber (top) is a Tesco bin. The dust will fall into the green water tank which was un-used in the garden. I cut tops out of some left-over chip-board - it won't get wet (hopefully) so even this terrible "wood" will do the job, plus it is re-using old materials which I like to do.
In the top chamber there is 1 turn of a screw - I made this by chopping up the old lid from the water tank. There is 4" drainpipe which will attach to some flexible aluminium tubing (for extractor fans) - this goes to the tool. All secured up well, gripfilled to within an inch of it's life :) It is worth noting how VERY weak the bin is - polyprop I think, but very very thin - it shatters very easily - I cut the most of my holes with a poker I heated in the fire... couldn't find dad's soldering iron (ok I could, but I didn't have the heart to wreck it, or my own for that matter!).
Down the centre goes the pipe leading to the chip extractor - this is mounted in the lid:
The whole top section will be sealed and will lift apart at the top of the green tank, here is the top plate of the green tank with a hole cut for the cyclone bin part - no trammel bar work here folks - traced a rough circle and winged it with the jigsaw. Does fine - it isn't a piston head or a guitar!
Here is this lid attached (grip-filled) to the cyclone part:
This is how it looks with it all bolted and glued together minus the top plate with hose. I have used expanding foam to fill any gaps around the drainpipe.
Here is a show looking into it with that foam starting to expand. It is awesome stuff.
Ok, not much to say - I will complete this tomorrow and hope that the extractor comes soon - looking forward to a dust free experience :)
Back to the show tomorrow night - last week was really successful, so here is to another fun run!
God bless,
Mike
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