It is a project of an etching tank. The principle of operation is the same as in most etching tanks. One significant element added to a classical construction of such devices is mounting of the board, which is hung on a round plate moved by mini motoreducer.
Assumptions:
the etching tank should have a simple construction
reliability
without unnecessary electroni circuits
solid construction
The etching tank consists of:
aquarium
40W heater with thermostat
aquarium pump
mini motoreducer 4rpm
power supply for the motor
The board is hung on an acid-resistant wire, which is mounted to a rotating disk. That causes the vertical motion of the board. The motor with disk moves the board in a solution inside the etching tank. The motion of the disk can be disabled.