Hi Dave, looks good. I'm sure the extra space will soon get eaten up with wiring and other goodies like clive mentioned.

I would maybe swap the drives and the bob though and to try and keep the "clean" signal cables away from the "dirty" mains/drive power cables as much as possible?

I think most people would consider safety relays a step too far for smaller machines. They have features monitoring to detect if the contacts have welded shut but many don't worry about it. Really depend on your personal view of safety :)

I picked up a nice one for about £20 on ebay and it also has timed shutdown on one of the contacts which is nice. Can be quite large though and the ones I have seen are all din rail mounted.

Jim