Thanks for the info - been looking for my ISPTiny programmer.. finally found it tonight.
I used the Arduino IDE and set the Board to be an Uno and burned the bootloader into the Nano. Recompiled Grbl 1.1 and now I have it running on the Nano/Uno board.
More detailed info on how to do this here : https://github.com/grbl/grbl/wiki/Frequently-Asked-Questions Search for "I've got a Duemilanove-compatible board and I can't seem to fit Grbl onto it! What do I do?"
So my guess is this thing uses spindle speed PWM to drive the servo?
My pen servo is all over the place with 1.1 - do you know which config options will get it working like 0.9 ?