Noisy X-Axis
At certain speeds the X-axis makes a very loud buzzing noise. I've tried holding every part of the printer (including the LCD, which is prone to buzzing during large Z movements) and can't find any part that is making noise. It sounds like the sound is coming from the actual belt. I've replaced the entire X-Axis (except rods) including the bearings (tried with polymer bushings, too), idler pulleys, different models for the end blocks, and also the latest revision of Prusa-designed ends. The belt doesn't seem to be rubbing on any plastic or the idler pulleys. It just seems to make a loud buzzing when printing solid infill. When printing perimeters I can hear it, but it isn't nearly as loud. Slow movements like external perimeters are quiet. Ideas?