I think SM is a pretty cool guy, eh builds unicycle-bots and doesn't afraid of anything
is this bot don't lost all razors in a fight before do a damage thought
Actually, you only need one black. Assuming that there are only four spin motors, they draw a combined total of 40 amps, and you are supplying them 160.
Removing one of them will leave you with thirty extra kilos. Although I'm not quite sure what to do with them, so this is optional.
Also rotate all of the razors with the same orientation, as Wacky Bob (indirectly) said.