My R1+ is having an issue with the y-axis stepper. Right out of the box there was considerable vibration / "grinding" when the y-axis was in motion. I pulled the stepper motor out \, spun it around a few times back and forth, plugged it all back in and it ran fine... for one print. On the next print just as it started layer 2 it started the grind again and fails to follow along that axis. I have read all the threads I was able to find doing a search and none are helping. I pulled the bed off, removed the belt and in the stepper motor itself I can feel and hear the grind. Do I need a new stepper motor? BTW, if I help it out a little and apply a tiny bit of torque it seems to spin much better if not just right. Also when sending a y+ or y- command it doesn't always know which direction that it. I'll hit y+ and it goes + then I hit it again and it goes -.