In this video I try to build a basic platform for a quadcopter with salvaged motors from small axial fans and some other household items.
These (like all PC-Fans) are powered by BLDCs (Brushles DC-Motors). You cannot reverse their rotation by changing the POLARITY . That only works with old fashioned "Brushed DC Motors".
Model number of the Server Power Supply: HP - DPS - 700 CB-A.
I recommend you not to buy this unit simply for this unit . A wide variety of fan -motors, salvagable from several devices / manufacturers could be used.