My Ultimaker 2 makes a rattling sound when moving on the X axis. The rattle does not seem to influence the print, so I guess it's not the belts. I've included a video depicting the X axis stepper motor and belts, in the background, the sound can be heard clearly.
Please help me solve this issue. Right now it's just annoying, but I'd rather fix it before something gets broken or damaged.
Thanks,
Martin