Equator

[Bramberg]

Hello to you all. This is my first entry in this forum wich topics; spinning dust into cans  :)

I am a full time construction capenter. My main dust producing tools are the miter saw, electric hand planer, hacksaw, rotary sander and bench drill.
Since I am moving around alot betwen smaller projects I try to travel as light as I can. This is why I bought the smallest of the Festool vacuum machines The Festool CTL Mini. In europe this model has the same motor as the bigger models and just about the same extracting capacity. The biggest model extracts 3.900 liters (1030 gallons) per minute and this smallest one that I bought extracts 3.700 liters (977 gallons) per minute.
The downside is that it has a small dustbag at only 7.5 liters (2 gallons). This is fine for tidying up some breadcrums but for collecting dust and chips from a miter saw or planer this will not work. I will have to build a good dust separator for this. I've studied videos on youtube on the Dust Cyclone and the Thien Extractor and have made some plans for the one I'm going to build.
I hear great things about these extractors efficiency and I hear some people that have alot of problem with clogging and such.
I meditated on how this thing works and realised that it's pretty much the same dynamics as in a low preassure weather system, a tornado or - a cyclone.
When I pull the plug in my bathroom sink, the water goes down with a clockwise rotation. It's known that on the other side of the equator it's the other way around, same with weather systems.
I don't know the importance of this in building a dust extractor. But does anyone has any say about the rotation direction of the airflow when building one of these extractors?

Thank you /Bramberg

[RonS]

Why fight Mother nature?

[phil (admin)]

The rotation of water down a drain has more to do with the design of the sink (size/shape of bowl, length of drain pipe, etc.) than the rotation of earth.

So make your separator spin any direction you like.  You won't notice a difference one way, or the other.

[Bramberg]

The rotation of water down a drain has everything to do with the earths rotation. You can force it to spin anyway you like but if you let it choose it's own rotation direction it will always go clockwise north of the equator and counter clockwise on the southern hemisphere. This might have small effect on a dust sepparator but then again it might be just the sort of thing wich makes it work just good or that makes it work Great! I gather noone has tried switching direction to investigate this then.

[retired2]

Hmmmm.....I wonder if NASCAR built a track in the southern hemisphere they would race clockwise rather than counter-clockwise for faster speeds and higher fuel efficiency?   ;D  Sorry for the cheap humor!

Actually, the Coriolis Effect, to which you refer has little, or no effect, on most vessels created by man, and that includes your bathtub, sink, and commode.  It is incorrect, that the water in these vessels consistently swirl in one direction in the northern hemisphere and the opposite direction in the southern hemisphere.  The rotation of the exiting water is determined by a lot of factors, but the Coriolis Effect is the least likely to have any influence.

And trust me the Coriolis Effect has zero effect on dust laden air traveling at several thousand FPM in a piping system or a separator.

The rotation of your separator might have some effect on your system's CFM if it is close-coupled to the inlet of your fan.  Under those conditions you can cause turbulance or cavitation in the fan depending on whether the rotation matches of opposes it.  Neither is good and that is why I ultimately added an air straightener to my separator to eliminate the turbulance.