Yes you can buy multiple different sizes of backing plates for a rotary. I use a 3 inch and a 6 inch. Flex makes damn good machines. If your looking to purchase a rotary i would go the flex route. Amoung many other reasons the big noticable difference is the wieght...they are pounds lighter than other brands.
Like i said b4, just get some junk panels to practice on so you can get a feel for it. Also when buffing...a lil tip...check the panel for how hot your making it. Heat is one main reason of how you burn through the clear. Edges of panels is another area to not spend to much time.
Just look up mike phillips as he has countless videos and threads on how to use a rotary machine. It will no doubt help you out when learning the rotary. I know it helped me, as i had nobody else teach me the ways of it
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