I took this picture of a team 575 mechanism today:
https://vexforum.com/gallery/files/2/0/9/1/team_575_pic_2012_feb_15.jpg
I wonder what it is?
Normal wheels not big enough for you guys? 
I have no idea why you would ever need a planetary gear, but if you do, then something is definitely interesting about your robot. Can’t wait to see it!
It’s not MY robot. All I do is order parts and try to get students to fill in permission slips…
It looks like a twist off of the tristar wheel
it looks like it could be used as a wheel or an intake roller…
I was wondering if this would work as a planetary gear. It is in one of my notebooks somewhere. Is it efficient without a lot of play? The reason I never built one is the fact it would be very large to include on one of our robots.
I think it’s a giant Autonomous Selector Nob! It mounts on to a potentiometer in the back (hidden of course…) 
No offense but it doesn’t look to sturdy with the chain bowing and the outer ring being a couple 1x25 bars :o
but other than that it looks like it could be a possible tristar wheel like Drbayer mentioned or a planetary gear
Rick, please don’t follow the teaser trend, its overrated! Haha, anyway, looks interesting. Could maybe be used as a wheel, but I agree, it doesn’t look like a piece of hardware that I would trust to support my bot.
It is a planetary gear box. Here is a picture of one
