Filament storage

A shelf that allows you to store filament under the ceiling. Designed for those who, like me, have little space for all their filaments. The project shown in the photos holds about 25 boxes of filament, which corresponds to a weight of about 35 kg (together with the spool, vacuum bag and box). The total weight of one shelf is about 40 kg and despite such a large weight, I can easily lift it with one hand. In my case, there will be 4 such shelves. Placing them under the ceiling means that they do not take up space under the feet or near the printer, and the ease with which it is lowered and raised means that they are quickly accessible. Such a large mass can be lifted with one hand because each shelf arm (I have 3) works on a multi-pulley (6 pulleys under the ceiling and 6 pulleys by the shelf).Each pulley is mounted on a bearing and there is a washer between them so that they do not rub against each other. In the near future I will slightly modify the pulley attachment to further reduc