I am hoping my 2KW 100mm Camvac (Wll mounted with bag) will be enough to get me started. Only one machine at a time using blast gates and a short run of ducting for my Table saw, Bandsaw, Thicknesser and router table. Thats all I want it for.
Thanks
I spent 3 months studying extraction and came out more confused than before I started.
The kw power of your motor is not the only factor you need to account for. It may in fact be of little use.
The first thing you need to do is determine the size of the ports on your machine.
That will give you an indication as to the required velocity and flow rate needed, to extract the particles.
1)The flow rate determines how fast the air moves
2)The velocity determines how much pressure is required to move that air.
Many machine manufacturers will five you the recommended velocity and flow rate required for their machine and if not, the size of the port, will help you get a ball park.
For example, if your saw bench has a 100 - 125mm port and a blade guard with a port for over head extraction (which you should have), say 60mm (anything less than 60-80mm is a waste of time), then the total required width of ducting to extract that machine, will need to be 150mm.
To properly extract the saw at an air flow of say 23 m3 p/h (which is the standard rate to keep dust elevated and travelling down a pipe without causing blockages), in 150mm ducting, your extractor needs to be able to keep up with that.
Then you add on bends, friction (which I think is higher in plastic), and drop over distance, you need to up the velocity (pressure/horse power) of motor. Now you can have a 2kw motor but it might have low static pressure.
Basically, if you run power tools, a cam vac should be fine, they all have sub 100mm ducting and therefore you want a low volume, high pressure vacuum.
If you run machines that have 100mm plus ports you may need a high volume low pressure system.
If you attached an dyson to a 150mm port, it wouldn’t do anything, which is somewhat similar to using a camvav.
So work backwards.
Start with the air flow which is 20-23m/s needed to suspend particles in the ducting.
Measure the dust port size on your machine and do a calculation to determine how much pressure you need to maintain the required flow rate, in that size of ducting.
For example to maintain a flow rate of 20m/s in ducting 120mm wide, you need a flow rate of 800m3 p/h at 900pa (pascals/pressure).
A 2kw camvac does 388 m3 p/h
Meaning a camvac would not be able to properly extract a single 120mm port on a bandsaw if the required air flow and velocity are above 500 m3 p/h at around 900 pa.
Basically it would be like throwing a hotdog down a hallway.
