Find here below mechanical drawings with dimensions. Front and rear sides are shown in blue. Top and bottom sides in red and left and right sides in green.
There is a squared chamfered 75 mm window in the front cover (140 x 130 mm), where the ionizer needle grid will be installed. An aluminum panel 140 x 50 mm and 2 mm thick is used to install 2 potentiometers, one switch and one blue LED.
Ø90 mm for the fan air exhaust. All sides and corners are filed and rounded to allow covering with red tolex.
The PCB fully assembled with front panel, potentiometers, knobs, power-on switch and power-on blue LED. PCB has been connected with wire cables to the AC outlet, fan and ionizer needle grid ready for testing with a digital multimeter.
The picture below shows the front panel with the needle grid installed as well as the aluminum faceplate with two knobs, power-on swith and power-on blue LED. The left button controls the output voltage of the ionizer, and the right button controls the speed of the fan. There is no risk in touching the needle grid or the screws connected to high voltage because they are protected with high impedance resistors, but an additional plastic cover could be added.