Stationary robots seem to be where Mindstorms owners become most creative. I've seen a number of piano-playing robots, but Mario Ferrari took the concept one step further by including a conductor, too. In his setup, the piano player sits in front of the keyboard intently watching the conductor (see Figure 7). The conductor reads in the sheet music, which is actually quite similar to piano rolls from old-time player pianos. Once it knows the note, it transmits it across to the piano player, who then plays the note.
Figure 7 Piano player and conductor (Photo courtesy of Mario Ferrari).
Robot arms are another popular creation with Mindstorms. The most impressive to date, the Cyberarm IV, is from designer Hideaki Yabuki (a.k.a. Joda, which means Yoda in Japanese). Hideaki's forte seems to be robot arms, and he is the best at what he does. He has designed a string of robot arms that are as complex as those on assembly lines. The CyberArm II has essentially every movement of a human arm, and it also moves laterally along a track (see Figure 8). His latest designs use Lego pneumatics for powerful movements, and all movements are monitored by the RCX using sensors, so the RCX always knows what position the arm is in (see Figures 9 and 10).
Figure 8 CyberArm II (Photo courtesy of Hideaki Yabuki)
Figure 9 CyberArm III (Photo courtesy of Hideaki Yabuki)
Figure 10 CyberArm IV (Image courtesy of Hideaki Yabuki)
Everyone dreams of making robots do all the work for you, but a few users made it a reality. No one likes to scrub the toilet bowl, so one inventor featured on the Lego site created a robot to do it for him. It is an impressive feat, though I personally wouldn't want to play with his Lego set after it has done its work.
Stuffing envelopes is a tedious, repetitive job, so an inventor created a robot to do the work for him. Using mechanisms employed in factory machinery, this robot stuffs letters into envelopes, one after another. There was no word on whether or not it licked the stamps, though.