Hello everyone.
Sorry for the delay, but for some unknown reason the notification of new posts has been disabled.
The plate is adapted to a specific engine from the seagate barracuda disk, it has 5 holes that perfectly match the holes in the engine housing. The spacing of these holes is not standardized, so other manufacturers use different dimensions. If you use a motor other than the one described, the holes must be adapted on your own. In my clock the propeller is attached only to two 2mm screws, it is enough.
The battery is placed in a socket which is soldered to the board. This stand has been removed from the cell key fob, which flashes when ringing. In turn, I took the keyring from my little cousin

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The main disadvantages are the lack of external communication and, of course, energy transmission via brushes. A coreless transformer will be used in the final version. However, the biggest step will be the use of tricolor smd diodes and an FPGA chip from the SPARTAN family. Perhaps it is too powerful a system for such a device, but I treat this project in terms of development.