Blow holes are not hard to make and most people will purchase electrical drill and hole saw or even a knock out punch.
However there is a easier way to do it without spending on expensive equipment. All you need is a hand drill and some 1/2 round files.
Last but not least, some filing skills.
Remember to wear safety goggles and gloves when you are handling tools. It helps to prevent unnecessary injuries. If you are not confident or not adult enough to handle tools.
Kindly consult adults or experience tool user as I will hold no responsibilities for any injuries or damages.
I intend to do another 80mm exhuast fan right blow the first exhuast fan therefore remove my mother board tray to do some measurements.
The diagram above shows you exactly what I am doing. I will not drill or cut on the actual diameter of the fan hole.
Instead I will work with the inner circle. Do draw these circles on your piece, you can use a compass.
Using a hand drill I drill pilot holes along the inner circle, once done. I will then use bigger drill bits to drill on the pilot holes.
observe the picture properly, those smaller holes are pilot holes and using bigger drill bits on them to cut more material towards the actual hole size.
Use metal cutter to snipe in between the holes. Once done, use 1/2 round hand file to file it round till it touches the actual hole measurement.
Simple and easy, though time consuming but it does the job with cheap equipment. By the way, don't forget to mark out 4 holes and to drill them in order to hold you fan.
