One of the bad things about most of our bot's design is the open-loop nature using stepper motors (without an encoder).
It ocurred to me that an accelerometer on moving carriages could provide a feedback loop that might be used to detect and correct skipped steps (if I am watching my printer and the head bumps into something missing steps I can fix that by pausing and homing the head before resuming). Three-axis accelerometers can be had quite cheaply these days.
But before venturing into more work I mention it here just in case some of you guys already did some tests and discarded it for some reason.
Maybe just the answer is to use optical encoders instead ...
