Hallo people,

(this is my first instructable so if anything is not clear feel free to comment)

in this instructable im going to show you how to mod your boring old pc fans.
I will be using RGB LEDs but you can use regular single color LEDs aswell.
For less experienced people I'd recommend using regular LEDs.

What u need:

- PC fans (or any other fan u want to mod)
- LEDs (including the data see step 1)
- wire
- drill
- hot glue
- 5mm drill bit
- soldering iron
- solder
- resistors (for value see step 1)
- tape (I believe the tape I used is called painter's tape or masking tape)

if u are going for rgb:
- rgb controller (u can buy these on ebay for 5-6$, CHECK: common-anode or common cathode )
RGB controller

- RGB LEDS (CHECK: common-anode or common cathode )

optional:
- paint (I asked friend to do it for me but forgot to ask what he used)

Step 1: Schematics

Before u check the schematic choose your leds and obtain their datasheet

things u need to know about your led :
- foward voltage (v)
- current rating (mA)

and if your going for RGB also check whether u have common anode (+) or common cathode (-) leds

now first off regular leds:

I'll use regular blue leds as example:

datasheet:
blue led
foward voltage:3.2
current rating max: 30mA (I will use 20mA wich is the common current for LEDS as 30 is max it could kill leds when there is a peak in current and it will also reduce lifespan)

I want 4 leds, 1 for each corner of the fan

they supply voltage for PC fan are yellow (+12v) or red (+5v), I the use 12v so I can put more leds in series.

using this calculator u can calculate what value resistor u need
ledcalculator

In my case the calculator tells me to put 3 in series with 120Ω resistor and 1 led with a 470Ω resistor.

I could also use 2 strings of 2 leds in series wich would need 2 300Ω resistors 1 for each string
see image below

its best to use 1 resistor as this results in lowest current being drained from psu but this can only be done with leds wich have a low foward voltage like red leds(1.5v 4x1.5=6v 6v<12v).

Now for the RGB LEDs:

its almost the same as with normal leds (as a RGB led is a mix of a red, blue and green LED in 1 case) u have to calculate your resisistors

as shown in the added image I used 470Ω resistors for all leds because I had a lot of them laying around resulting in a lower current for blue and green and a higher current for red but only a few mA and within the max current rating

I used a rgb controller (u can get one on ebay for around 5-6$) to test my finished fans.
For the single color leds u can simply use any 12v dc psu or adaptor (note: the adaptor has to have a higher Amp rating then the leds u are hooking up to it, but ussualy they go from 200mA to 5A so u can hook up 1000/20=50 leds strings on a 1A supply at max but its better to avoid the limit >better safe then sorry<)

if u have your leds and resistors right u should go for the next step

LED_fan_schematic.sch
Download

Step 2: Drilling

now we have the elektronics ready its time to mod the actual fans by drilling holes

NOTE: be verry carefull at this step if u drill to deep u could destroy the fan blades wich equals game over

the power cable got in my way so I used some tape to hold it in place while im drilling the fans

on the corner of the fan there are some plastic *walls* so I cant put my leds precisely in the cornor so instead I decided to put them all left next to the walls (left when u look onto the corner from above and the airflow is in your derection (u can find this printed on side of fan)).
remember to do all leds in the same way cause else It would look realy bad + I'd be hard to fix

I put some tape on the corners cause it gave me the best holes and also gives a little protection for the blades(very little that is).

I drilled the holes using a 5mm drill bit.

After drilling remove the tape en check your holes and fan blades

if u did a great job u can now go to the next step

Step 3: Building

NOTE: !! Check your leds (after using the hot glue I found out some of my rgb leds were dead and took me few hours to get them out and put new ones in without destroying anything) !!

before u start to build, you shoud put new tape on the corners covering the holes u drilled in step 2
U have to do this to prevent the leds from going to deep into the fan blocking the blades

to keep the leds in place I used hot glue and after that I bend the leds legs all to the same direction

after soldering all the resistors and wires I hot glued these aswell to avoid short circuits

because I use yellow, red, blue, and green wires the fan looks a bit to flashy so covered the blades and asked friend to paint the edges shiny black

this is optional, I can imagine some ppl want to see the work they did.

if all went well u can go to the final step