will1983":2iyji7it said:
How come you didn't make the outer edge of the drop slot level with the inner face of the baffle Matt? All the other threads I have seen show that it should be arranged thus to provide an unrestricted route for the chips/dust into the collection bucket. Have you noticed any build up of dust on the lip?
Maybe you could try adding a heavy chamfer to the underside of the chamber bottom plate. Apparently this will assist in the capture of material by reducing turbulence at the edge of the slot. I have done this with mine, chamfered enough to leave about 3mm of vertical material remaining. I made it this way from the start so have no before-after comparison.
Good news on the air flow increase but I cannot work out why this has risen by widening the channel. Have you observed any other improvements other than the airspeed increase?
Personally I think the Thien design can be tweaked for forever and a day and completely over engineered with negligible increase in performance. There is potential for disappearing down a Thien Baffle Rabbit Hole, therefore I believe the ultimate tests have to remain that "Is the air coming out cleaner than when it went in?" and "Is that air now clean enough to breath or be released outside without causing a nuisance to my neighbours?" I would be interested to hear your thought on that.
I wanted to maximise the diameter of the cylinder to ensure I had sufficient airflow. I had considered going no bigger than the internal diameter of the container, but decided to err on the side of caution - always easier to reduce the diameter of the baffle than increase it!
Before I put the deflector in, a small amount of dust would gather around the perimeter, but with the deflector in its down to hardly anything. I think it's a good solution for people to consider if their container isn't quite as big as they'd like.
I have no idea why increasing the channel width has increased airflow - I can only assume it's allowing a larger vortex to be created.
One other option is that the bin is about a third full now - I have seen a video from someone on YouTube who noted that the performance of their cyclone increased as the container filled up, so it could be that. I'll empty the bin and test for comparison.
I agree regarding finding a balance in performance - it is tempting to keep tweaking. I wish I had a design program that could stimulate fluid dynamics!
As for your two criteria - the thien eliminates every speck of chips and dust other than the very finest and any invisible particles, so the separation is outstanding. I wouldn't breathe it without some sort of filter that's able to capture the sub 5 micron particles though.
I'm more than happy to vent outside, without fear of neighbours complaining - they wouldn't be able to see anything visible coming from the vent.
