Im after a Pcb which needs to be a ring, or at the very least a ring. I was wondering if any companies do pcbs like this for one off orders? Worst comes to worst I could get it square and trim it but I would worry about the track breaking.
All PCB companies can make a very small number of PCBs...they'll just charge you a crapload so that you could probably get at least 10 the same price. It'd be much cheaper to trim a square board around the edges. Just use a rotary tool and a cutoff wheel so that it's an abrasive cut rather than a shear cut so no force is exerted on the board. Wear a mask though and do it outside! That dust isn't good for you to breathe in. Possibly wet it down too to help with the dust. GO slowly and give the edge ample room until you figure out how much the board might melt from the heat and slow down the RPM until you figure it out.
I'd definately try to get the hole in the middle done by the company though. That shouldn't be a problem...maybe...not sure if the hobbyist priced PCB servces will do a cutout for you like that.
i've done it that way also w/ a dremal tool and files. just as stated take your time. any more i just put a small hole in the middle and spin it off on a small metal lathe.
I guess you could also design your pcb with room for a small hole in the middle, perhaps with a pad. Use a hole saw on the square boards to cut them round. Downside is you will have a small hole in the center from the sawpilot hole.