I had the idea for this project after experiencing a lot of defects in my prints , mainly caused by humidity ( thanks to British weather ) and dust. The defects , clogging and you can observe them in the pics , courtesy of the website simplify3d.com (https://www.simplify3d.com/support/print-quality-troubleshooting/) and also due to the humidity , you would hear a small cracking while printing coming from the nozzle.The printer i used for this project was the Rostock Max V2 I received from SeeMeCNC and the hairdryer is a Bosch model (I made it so , you can add your hairdryer adapter and don't have to search on ebay for the model that I used).

Currently working on a cooling module for those of you who use a little more powerful hairdryer , and you don't want your filament to exceed 50-55*C. The hairdryer that I use has a off-half power-full power button , and I use it on half power for now. The temp goes up to 35-40*C so it's in the OK range for ABS and other high temp filaments , not so much for PLA.

Future developments: You can also add a filament sensor , to notify you when you are out of filament or it has the wrong diameter.

The design of the rollers was inspired by this project:
http://www.thingiverse.com/thing:1185076

Step 1: Bill of Materials

-large bed 3d printer , capable of printing 240mmx80mm ( if you land just short from it , you may be able to print it diagonally )
-about 500g of (preferably...mandatory) ABS filament . Temperature can reach 45*C inside so you would be better off with ABS or higher temp materials rather than PLA.
-4 bearings 625ZZ
-screws M3, M4, M4.5 ( not pictured )
-some glue
-a hairdryer - i used my girlfriend's old hairdryer , Bosch ( for the filament drying part ) - you would want one stick shape not pistol shape. It makes the design more compact.
-4 or 8 magnets neodym , 10mm diameter , 3mm thick ( 8 if you want the cooling module )
-a sponge (for the filament cleaning part)
-a sharp tool to clean your prints and cut your sponge

-a silicone stick glue
If you think that the temp inside is getting too hot , you can add a module with a 5V fan 40mmx40mm controlled by an arduino board with a temp probe inside - "cool" but still hot ;) . - you will also need a 9v adapter to power your arduino.

The design is modular so if you want to improve it , you just print a module , not the whole thing.
This design is for spools that have a maximum diameter of ~205mm , and a width of ~52.5mm (usually 500g-750g) . You would be able to fit in larger ones if you increase the size but I don't have a printer that big.

Good to have : laser thermometer

Step 2: Files

You will have to make your own adapter , i will post mine in case somebody out there has a bosch hairdryer on hand. The rest of the parts should be the same as mine , in case you stick to the basic model. If you want improvements , remember... keep it modular. It's better for the community . :)

You can break off the "Mickey Mouse" ears after you finish the print, I made them because my ABS would warp like hell, I had to dump a print at 85% because of the warping :( .

Some of the parts i designed in Fusion 360 so that it would be easier to be customized by the users out there and some I designed in Catia V5 because this is the software I normally use. will post the design files on the 20-25th of december because I have to make some corrections ,but for now , you have the STL's.

files can be found here : http://www.thingiverse.com/thing:1936600

Step 3: Assemblying

Lets start with the Cleaning Filter.
Using your sharp tool , cut a piece of sponge of just the right size , not too big because it will create lots of drag , not too small because it will go all the way trough the hole.
Then , attach it to the lower shell using glue. You can also use glue to attach the sponge to the filter case so it won't move around.

Step 4: Assemblying Part 2

In this part we will assemble the rollers... or tumblers .
As you can see , in the assembled position , the rollers have 2 walls that prevent the spool to go either left or right touching the walls or falling.

Glue the blue and green parts ( as they appear in the Catia rendering ) . They have complementary shapes , so they will fit just fine.

Place your bearings inside the printed roller parts , as you see in the image and glue them in place.

Place the rollers inside the lower case and secure their place by driving the M4.5 screws from the sides , trough the small bearing's hole.

Step 5: Assemblying Part 3

Place your magnets in the holes of the shell , and glue them in place.
I also used an old soldering iron to melt some filament and cover those powerful neodym magnets.
These magnets will insure your shell won't loose it's top part at every small vibration.

Step 6: Assemblying Part 4

See if your hair dryer adapter fits your hair dryer . After that , place the adapter inside it's hole and glue it with some silicone stick glue . I made the diameter like 1.5mm smaller because i wasn't sure about how well the printer will print overhangs , so you might increase your diameter to your needs.

Step 7: Finished

Still to come , a cooling module controlled by an arduino board which will unable active temperature control as opposed to just relying on those vents.
Don't worry, it will be modular ;)

You can support future development , not only of this project but of many others as well , by sharing it with others.