Cyclone Dust Separator

Just about any functioning woodworking shop has some kind of dust collection system. For some time now I have been using my shop vacuum to manage the saw dust in my workshop. This works fine initially but it doesn't take long before the filter starts to get clogged and the vacuum loses suction and effectiveness.
So, I needed to do something but didn't want to spend a lot of money. Not only did I not want to spend the money on a costly dust collector I don't really have the space for one. Well I was watching an episode of the 'Woodsmith Shop' and they did a short feature on a cyclone dust separator and that got me thinking. I started doing a little research by reading some articles online and found a simple cyclone separator on 'WoodworkingTalk.com' that I thought I could make myself and the version I used is loosely base off the one I found on there.

The system consists of two 5 gallon buckets and a few fittings. Within the top bucket there is a cone that funnels the particles down into the lower bucket through a 3" hole (which may be a little small-4" might be better). For the cone I had an old graphic that I formed into a cone and riveted together. This first version I made is more or less a trial run, if I should decide to modify it I will pick up a traffic cone and cut it down to fit into the bucket. Before I installed the cone I drilled the hole through the bottom of the upper bucket and the lid to the lower bucket. I then bolted the upper bucket and lid together and installed the cone and secured with some heavy duty tape. With the upper bucket & lid placed onto the lower bucket the bottom half is complete.

I used 2" PVC pipe for the down tube with a rubber elbow at the top. I couldn't find plumbing fittings that would fit the 2" vacuum hose fittings so the rubber elbow was an easy solution to make the transition. From the research I had done it appeared that the down tube extended down well into the cone. I don't know the exact formula for this but my version seems to be working well. As for the intake I drilled the hole as close to the edge of the lid as possible and used 2-90 degree fittings with a small piece of PVC between the two to create a 'u' shape. It seems that most of the diagrams I looked at show the dust intake either entering the side or coming in through the lid and making a 90 degree turn which I guess makes sense to initiate the rotation.
I got in a bit of a hurry and put this together without reinforcing the lid. With the hoses hooked up to the fittings the flimsy lid just isn't quite sturdy enough to maintain it's shape so if/when I upgrade my prototype I'll be reinforcing the lid.
So far I've given this setup a couple good tests and it works quite well. It seems like the system is catching about 80% of the dust and particles which will go a long way in saving my shop vacuum. I also never noticed any loss in suction and that is probably the most important benefit.
That pretty much wraps up this entry thanks for reading.
Rex