Hi,
I have bought a 130CFM inline 3" fan to replace the one supplied with the K40.
I am a little worried it might not be enough draw but I will install it and see.
I have read this ;
Having the fan directly at the back of your machine put alot of pressure on the fan.
It has to do two things. Both creating a negative pressure inside the machine to suck the smoke up, and creating a static positive pressure, to push the air in the 4-5 meter hose.
Positive and negative pressure works against each other, moving the fan to the end of the fan will almost be 100% effect on sucking (negative pressure) as there is no positive pressure built up.
from
https://k40laser.se/exhaust/https://k40laser.se/exhaust/is this true?? I dont know enough to judge the accuracy of what they say but it sort of makes sense, but then again it doesn't as to me if there is a negative pressure there will automatically also be a positive pressure, you cant have one without the other!!!
there they also mention;
Tips for having a optimized exhaust.
1: Buy a in-line fan matching the hose you are using, 100-150cfm is enough
2: Put the fan at the END of the hose, where you evacuate the smoke (window sill for example)
3: Seal your machine to prevent smoke creeping in to your room.
4: Have a good working smoke assist in your machine
so the fan I got might be ok...
Ki
=)
