40mm fan block for i3 mini

A slider to block some or all of the fan from blowing on the part on the Wanhao i3 mini,
Monoprice MP i3 etc style printers.
It sandwiches between the fan and mounting plate/block and can slide back and forth while printing to adjust air flow to the part only while allowing full flow to the heat sink.

I added this to the duct linked below so it seals really well.
https://www.thingiverse.com/thing:3270472

Tinkercad link in case you want to modify it;
https://www.tinkercad.com/things/4