is this return pulley that is the most popular or fashionable return pulley
and is made by Ober Flugmodellbau in Germany. Most of pilots who enter for
the F3B European tour. It is design to be compact and low resistance. It
is told that its pulley moves up and down in a magnificent way while launching.
The reason why the pulley must move up and down? There is no need for the
pulley to move, when only one flier fly his ship. However, when many fliers
fly at one time such as championships, the situation is different. After
launching, the strings will start to be retrieved at one time, Those strings
with parachute run low on the ground transversely. At this time, one string
rubs another string if pulley is at 50cm high according with F3B regulation.
It results in being cut the high mounted string by running string inevitably.
Therefore, your string should be low on the ground as far as possible by
moving pulley down, when it is not your turn. This is the reason why return
pulley must move up and down. (By Asano, F3B flier at Akagi, Japan)