I need (read like) to print things, small or big, from PLA or ABS, so I need a large printer, enclosed one, reliable and easy to use.

My printer is a corexy self-made one, enclosed and with my version of cross flow approach for cooling. I use a cross flow fan for cooling the hot end and the filament. Also the laminar air curtain keeps the heat inside the printer cabinet - I don't have top enclosure.

I ordered a fan on eBay but it takes too long to get there. So I did one. A 40 x 300 mm cross flow fan

Complete Bill of Material – 09.09.2017

a 12V 120 mm fan like this;
2x M105ZZ bearing;
an 5mm diameter aluminum rod, 300 mm long;
M3 nuts and bolts;
1x 0.3 ohms 3W resistor;
1x 47 microF/16 V capacitor;
1x complete set of printed parts.

Step 1: Destroy Your New Fan..., Have Fun

You need to free up the motor from the fan cage. With a plier you can cut of all the propellers and support from the motors. After that you will sand the motor to have a smooth diameter.

Step 2: Print Your Parts

Print the 2 propellers and 2 x propeller top from ABS with a 0.4 mm nozzle. Print slowly to have a good quality print. And no support for the propellers.

The rest of the parts I printed from black PLA at normal speed. Just be sure they are not distorted/warped.

Printer settings: 0.2 mm layer, 30% infill, 30 mm/s for propellers and 60 mm/s for the rest of the parts.

Step 3: Build the Fan

After I printed the propellers and the propellers top I glued to make the final propellers. So take the 5 mm rod and press to one propellers and one top propellers. Center the top propeller and glue to propeller with superglue. Repeat for second propeller.

Glue together case 1, case 2 and top case.

Now press the motor inside propeller 1. Press the motor support on the other end of the motor.

Press fit the bearings on case, one on middle and one on top. Now insert the aluminum rod into propeller 1 and put the propeller 2 on second case part. Insert the propeller 1 with aluminum rod into first case and into second propeller. Tight the motor support to case and after center all the parts you can glue the motor to motor support.

The cross flow fan is done.

Step 4: How to Use the Fan

I use this fan on my printer witch is powered by ramps 1.4. I connect the fan to D9 connector.

Optional to smooth the control of fan I use an RC filter. I setup the PWM control to 10% for preheating and 12-15% during the print. For bridging I use 50%.

Cool printing.