https://www.youtube.com/watch?v=PoKxVNX81tg
MAGNETIC rail
The rail is in a horizontal position, the ball is NOT rolling down.
The (magnetic)ball moves through the blockmagnets which are located on the H profile.
Sphere magnet Ø 19 mm
NdFeB, N38, chrome-plated
http://www.supermagnete.nl/eng/K-19-C
Blockmagnet 10 x 6 x 2,5 mm
NdFeB, 42SH, nickel-plated
http://www.supermagnete.nl/eng/SALE-035
20-10-2012
https://forum.davidicke.com/showthread.php?t=225312&highlight=magnetic+rail
22ND OCT 2012
http://science2art.tumblr.com/post/34095378010/magneticmagnetic-rail