Bought these: http://www.ebay.com/itm/280875300072?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
And I'd like to connect a platform to the motor (that would spin) but I don't know what such a part would be called. Any help?
prismspecs:
Bought these: http://www.ebay.com/itm/280875300072?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
Ha! I salvaged the same type motors from a toy micro copter.
And I'd like to connect a platform to the motor (that would spin) but I don't know what such a part would be called. Any help?
The thing that connects to the spinning part of the motor is the shaft.
Shaft coupling
Something like this put smaller: ACHSKUPPLUNG 2: Achskupplung für Potentiometerachsen, gold bei reichelt elektronik
A hub? A bushing?
http://banebots.com/c/WHB-HM
And I'd like to connect a platform to the motor (that would spin) but I don't know what such a part would be called. Any help?
HYP-NO-DISK. watch it slowly start to turn... slowly turning... let your mind relax... let yourself go... send me money...
Well whatever you call the part, I'm sure it gets dizzy. 
Lefty
The two common names are, shaft and rotor.
ALT: The thingy that sticks out of the motor and can attach things to.
The thing that sticks out and you can attach things to it 
The thing that sticks out and you can attach things to it
Yes, that is what my brother called it, when I was trying to teach him about how motors work.