Proposed homemade author Instructables under the nickname mosD is an analogue of the oil floodlight company Mathmos, better known as a manufacturer of original lava lamps. The effect is similar, but flat on the big screen.
The master cuts two identical disks from plexiglas 3 mm thick, each with a diameter of 150 mm. Using pieces of plastic provides between them a gap of about 1 mm. Glues and seals the seam, leaving only a small hole for filling.
Paraffin oil is poured (the article says that it is paraffin, but solid at room temperature) and water, to which dye can be added if desired. After pouring, it also seals the hole intended for it.
Installs the LED module on the heat sink through thermal grease or thermal padding, and also assembles the optical system from parts from an old slide projector. The LED module will be powered by a low voltage - from 5 to 9 V at a nominal 12.
Places racks, optical system, PSU (not pulsed, but pulsed with a suitable output voltage is also possible) on a laminate base (suitable for plywood). A shaft sticks to the “sandwich” of the discs.
On that rack, which is closer to the center of the base, it installs a sliding bearing, and on that which is farther away - an engine with a gearbox that provides a very low speed (from a microwave oven, for example). The shaft lengthens and collects everything so that the engine slowly rotates the “sandwich” of the discs. Checks the device in action, adjusts focus. Everything works.
The master assembles the body from the same laminate:
Initially, the master suggested that the reduced supply voltage of the LEDs in the module would dispense with a fan. But it turned out that after installing the projector in the case, it was still required. The wizard adds it, and then completely assembles the projector. On the side of the case opposite the fan, holes must be provided. Also pay attention to the interesting design of the legs.
Such a master turns out to be an interesting oil projector that works no worse than the original Mathmos company.