Just a note on spinners:

Jonno's said Chatham is important to show off what the class is capable of, and how entertaining they can be (especially if we go with a head-to-head structure). So making the robots and fights as good as possible only makes sense. However there will obviously be a small number of middleweights at the event and indeed for a good while. This means it's necessary to avoid causing terminal damage to any of the entrants, as that won't do anyone any good.

So if you're building (or thinking of building) a spinner, please don't make it completely overpowered for everyone's sake; this has been agreed by a number of MW roboteers. If you're designing with foreign competitions in mind (RoboGames, FMB, etc), then by all means make as destructive as you'd like, but you may want to tone it down for the UK live events.