Part Cooling Duct for Tevo Black Widow & 40mm Fan

Note: This is the "Standard Version"

Volcano version can be found here: http://www.thingiverse.com/thing:2217394

This part cooling duct and nozzle is for use with a Tevo Black Widow 3D printer and a 40mm fan. File for compatible velocity stack also included.

With the right duct and fan, and velocity stack combo you can boost the airflow through the system, giving the part maximum cooling and better printing.

I aim to make all my designs elegant, efficient and effective. The 3Es! Feedback is always welcome.

I tried many cooling duct systems, but I found that "adriansm's" design ( http://www.thingiverse.com/thing:1964762 ) was the only one that worked. After a while the tight fit and the thin walls of this duct started to melt and distort.

It was time for an improvement. It was time to design my own.

Using my knowledge of aerodynamics I felt I could not only design a more resilient duct, but also a more efficient version as well.

Using gentle curved surfaces and also an internal fan hub fairing, this design keeps the air moving in a more laminar flow while also providing the connection to the print bed without the need to print with support. Its a win win design!

Please give this one a go you will not be disappointed.

When connecting ANY layer cooling fan follow the Black Widow "Community Guide" in Section 11.6.2 and connect your fan wires to the "FAN" terminal on the MKS 1.3 or 1.4 board. When setting up your slicer, the cooling must be "off" for the first layer and should be set to reach your slicers maximum flow at about 0.6-1.5mm layer height.

Keep in mind that fans by different manufactures come in different flow rates. This means that ALL layer cooling ducts will reach a point of "thermal runaway" if you pump too much air through them. To prevent a thermal runaway, increase the layer height at which the fan kicks in at 100% AND/OR reduce the power going to the fan AND/OR put a sock on the heating block.

If you are still getting a thermal runaway at 100% fan speed, and you have increased the 100% layer height beyond 1.5mm and you do not wish to use a sock on your heater block follow these steps:

1. Pre-heat your bed and extruder to your normal operating temps as if you were preparing to print.
2. Perform an auto home.
3. Set the Z-axis height to 0.8mm
4. Perform a "PID auto tune". (See BW CG)
5. Add 0.2 to the I value, and add 10 to the D value. Note: adding these values helps the board adjust more quickly allowing for extra cooling produced by the layer fan.
6. Set the extruder PID values.
7. Using the selector knob go to: Main/Control/Temperature/Fan Speed
8. Set the fan speed to "100" - Note: the maximum for this setting is 255.
9. Return to "Info Screen" and monitor the extruder temperature.
10. If after about a minute the temperature maintains its setting or dips slightly then recovers then increase the "Fan Speed" by 10.
11. If the temperature continues to drop and goes in to a "THERMAL RUNAWAY" error state then take note of THIS "fan speed" (FS) setting.

((FS-12)/255) x100 = "fan speed" % = slicer setting for cooling

Example: if you get a thermal runaway at a fan speed of 190 then,

((190-12)/255) x 100 = 69.8 Then set your slicer cooling to 70% at 0.8mm layer height.

The above technique will probably work for most layer cooler designs. Whether or not any particular cooler is "effective" is purely subjective and in the end is proven in your print results.

Edit: If you know the fan is super strong like the Sanyo San Ace 40 9CRA0412J508 then start the fan speed at 5 and increase by 1 and use 3 instead of 12 in the equation.

This design has been tested without a sock with several cheap fans and has never produced a thermal runaway situation with a fan at 100%. That said 6 people out of the 1500+ downloads do date have claimed this duct will "always" produce a thermal runaway. However more users have said this is the "best cooler ever", which it is not. This design is a design that you can print without a layer fan so you can print a better layer fan like the "Evolution" series.

If a thermal runaway is encountered using this layer cooler post a comment here and I will help you. Posting any issues concerning this layer cooler in the Black Widow Facebook group will quickly attract the attention of one particular "troll" who will give the wrong advice, in which case I can not help you.

Compatible with:
http://www.thingiverse.com/thing:1937278

Use a 4mm nut and bolt to secure to mounting plate.

Thanks to adriansm for the inspiration and mounting design.

Please check out my other thingis!