at 8:30, the equation of w1/w2 does not make sense if b2 = y1. I think there is a mistake on previous slide . Vn2 should be equal to d2/2*w2*cos(b2). It is apparent from the figure also. Vn2 is in cosine direction.

Thanks for making these videos

Hi. When load lift up motor supply on time good moving up . But when load lift down motor supply stop but load not stay.Why reverse moving time with load not stay . Automatic load coming down. What problem please clarification give.

Very good, my colleague

Elevator Motor ----As for the gear box, it is a small box that contains oil and has two gears... The first is a helix gear, which is connected directly to the motor and is the driving gear... The second is a regular gear with teeth that connects to the drive gear, which is the driven gear... A box was manufactured. The gears are engineered in this way, so that the motor can always move the gear wheel, and the gear wheel cannot move the motor even if the brakes are applied... This method is very safe and smart, so that a rapid fall of the cabin does not occur at all, even with the brakes applied.

nice lectures sir!