Inspired by Alan Bishop’s post on the CVWA web site ‘Cyclone dust collection for your vacuum’ (May 14, 2020) I embarked on a similar journey. For some time, I have had a commercial 2hp dust extraction system (with pleated filter) plumbed to my lathe and linisher. Emptying the dust bag was a minor hassle and once the dust bag got to about one third capacity there was a reduction in air flow. Alan’s article got me thinking about adding a cyclone system.
The cyclones similar to that which Alan purchased for his workshop vacuum have inlets and outlets around 50mm diameter. All my existing plumbing was 90mm or 100mm diameter and I did not want to reduce to 50mm and adapt back to 100mm. It is possible to purchase cyclones (Oneida) out of the US with 100mm inlets and outlets but they are not cheap. Larger cyclone systems (Hare & Forbes; Carbatec) were not an option because of limited space and cost. So, I decided to build one from scratch.
I purchased a 60L drum with a sealable, but easily removable, lid and then plumbed in a cyclone system (see photo). These heavy-duty plastic drums are available in 60L, 160L and 220L capacities. I would have preferred a 160L drum but could not fit it into the space available.
For the inlets and outlet I used 90mm PVC pipe fittings. The 90mm outlet pipe has a 90 to 100mm adaptor that connects to the 100mm flexible dust hose attached to the commercial 2hp dust collector.
Inside the drum the inlet pipe has a 90o bend directed at the side wall of the drum to create a cyclone (see photo). The outlet pipe needs to be located in the vortex (middle). Blast gates at the lathe and on the inlet from the linisher (see photo) allow isolation of ducting and machines.
After assembling the system I did a ‘before and after’ weight test similar to that done by Alan Bishop. I collected and weighed 2kg of dust and shavings, then put it into the inlet pipe at the lathe. I then weighed the contents of the drum. My home-built effort captured 99.1% of the dust/chips/shavings. This compared favourably with Alan’s system removing 99.7%.
The system has now been in use for a few weeks and I am very happy with how it works. A search of YouTube or Pinterest shows that there are many variations for home made cyclone dust separators and one of these may suit your situation.