• double pendulum
• klein bottle
• grand piano
• platonic solids (dice)
• finger sized unknots and knots (rings)
• oh no my fibonacci spiral
• drumstick from cool band
• metal puzzles
• coup
• nintendo 3ds
• rubik's cubes
• sinnoh gym badges
• physical world ain't ready copy
• cool lighting (lamps, projectors, led strips)
• raspberry pi
• fender orange mustang bass
• sire 5 string natural jazz bass

already have

• gyroscope
• newton's cradle
• borromean rings
• finger sized trefoil
• finger sized unknot
• frog torus