Wanhao i3 plus ExtruderFan Shield. Better ABS prints

- Tested! all good.

- Print the shield and spring. Put the spring on the shield. Put the combined parts over the extruder fan.

This model will cover up the front opening on the heatsink as well as the side of the fan.
- When printing abs, you never want cool air present, this will prevent that.

I made this after using cardboard for multiple weeks once i noticed that simply blocking the air resulted in a lot stronger parts.