Storm in teacup (acetone bath)

Materials:

• 4L sealed box made from PP
• HDD motor from old 3.5" 250GB WD drive
• Model aircraft ESC for brushless motors, you may use almost any model, i used Turnigy 20A
• 12V PSU, 10W is enough (1A)
• Servo tester, i made one from ESP simply because i don't found pot in components box :)

Motor plate designed in FreeCAD.
Impeller is modified version of Centrifugal impeller, unfortunately i lost source, but modifications are easy - holes to tightly fit on motor outer dia.

To assembly you need cut hole for motor and drill 4+3 holes for M3 screws,
then apply silicone sealant and tight screws. Then check impeller, i used disc spacer ring to mount w/o disbalance.
Then solder ESC wires to motor, there should be 3-phases and (possible) central output, use ohmmeter to find phases (mine have 4 Ohm phase-phase, 2 Ohm phase-center).
Check rotation direction, if it wrong you may change ESC settings (if it supports) or swap any 2 phases.
When all tested to be working i sealed wires with ABS juice (plastic in acetone) and glued impeller with thread lock.

ESP8266 is not required, just i don't have free servo tester, so i made one with MQTT control :)
It connects to MQTT broker (mosquitto), then using MQTT Dash i may control PWM value. "Smart" vapor bath :)

Benefits from HDD motor - it is sealed (use less acetone, no losses via motor hole),
and it is very quiet!

Also i use spear stand for a while, it is useful, but require strong metal backplate.

Place pice of cloth to bottom, it helps to evaporate faster.