I have a Liteon DVDRW drive within my PC. Its your standard drive with an ejectable tray. I've opened up on before and there isnt much to speak of. I do see the lens and the tray but what the heck is used to initiate and maintain the spin of the DVDR during reading. I see no elevated center clip which attaches to the middle of the disc, i see no over/under hanging pad which will press up agaiunst the disc.
What is used to spin the disc? WHatever it is it certainly doesnt scratch the bottom of the disc nor does it leave it overheated due to friction.