Ball wheel sketch 1

I wanted an easier way to move my drumkit around through my room. This is one idea i'm working on. Since i wanted to ask some people for feedback, i decided to share my current progress here. As a matter of fact, any feedback is welcome, so if you have any ideas, please chip in!!

The obvious choice would be to go with "shopping cart wheels", but the problem is, they need to align first before the start rolling easily. So the first 10 cm is very tough, also they don't play nice with carpet.