Fitting a case fan

The simplest fan mod is the removal of a factory punched-out grill and replacement with a simple but elegant chrome wire guard. The process is as straight-forward as it looks – remove the fan, cut away all of the existing metal and screw it back together. That’s the theory, but the reality can be a little more complicated depending on the tools that you are using. Best results will be achieved using a fine cutting tool (hacksaw, jigsaw, Dremel cutting wheel) to ‘nip off’ the OEM grill around the perimeter of the hole, and then remove any sharp edges, or burrs, with a metal file. The final step is to smooth off the opening with sandpaper and, in the case of steel, coat the cut edge with paint to stop rust – in small area’s like this, clear nail polish will work as well as anything else!

When you are adding a new fan port, the modus operandi is very much the same, but with a few additional steps; the first and most important thing being location. There is no point adding a fan, and then discovering that it impinges on another component – one of the more common mistakes is adding a top blowhole only to realise later that it is in the way of the PSU!



So, be ‘environmentally aware’. That is, aware of the restrictions of the environment that you are working in. One method is to take some reference pics of your case with your system in place before you start, and refer to them as you progress. Another solution is to assemble a few cast-off components, such as an old PSU, MoBo, etc., that can be used for mock-up purposes without the fear of destroying something useful. Make all of your measurements, and then check them again, as even the best tradesmen and women get it wrong occasionally!

With the location sorted, the fun begins! The easiest and fastest way of cutting away the metal is with a hole saw and bench drill, but as that might be beyond your budget we will do this the ‘skill building’ way. Firstly, define the exact position of the fan, and mark out the four holes for the retention screws. Most pencils won’t fit down inside the holes, so the use of a centre-punch or large diameter nail will make the job easier. Drill the holes, attach a fan grill and then mark a line around the inner edge of the grill as the hole perimeter. This will ensure that your fan, hole and grill will all line up perfectly.

Cutting away the sheet metal is obviously more involved than in the case of the OEM grill, but utilises the same tools. When using a hacksaw, hand nibbler or jigsaw, you will have to drill a ‘pilot hole’ large enough to fit the blade into as a starting point, whereas the Dremel can start cutting on any point along the scribed line. There are some alternative Dremel cutting bits that can be used when working with plastic or aluminium, such as the #199 High-Speed Cutter shown here, but they do have a substantial additional cost that must be budgeted for. We find that the #426 reinforced cut-off wheels are a good starting point if you already own a rotary tool, but prefer to use a jigsaw wherever possible – there is no substitute for industrial-level cutting power and flexibility!

Regardless how you have cut out the metal, the next step is to file and sand off the edges of the hole so that there are no sharp edges. Use a fine, half-round file in curved strokes to remove all of the jagged burrs, and then finish off with carbide sandpaper. The tool on the left of the file is an invaluable aid to getting a perfectly round finish; it is called a drum sander, and is attached to a power drill. As the name suggests it sands as it spins, and as it has a curved surface it will help remove ‘waves’ and ‘bumps’ from the perimeter edge. The last step in a steel case is to seal the surface, as mentioned above.