No, that’s not normal at all. If it’s been doing this since your first plot, it sounds like your machine may have had some damage in shipping, or perhaps there is a problem with the power supply. Please contact customer support directly so that we can follow up personally, ask some follow-up questions, and determine the best way to get you back up and running.
Your grinding sound is when the motor “cogs” to the wrong position — that’s “loss of position control” as described in section 11.4 of the user guide. If you were running near the upper end of the speed range, I might advise that you turn down the cornering speed factor, but my suspicion is that something is _very_ wrong if you’re seeing this at speeds like these. If you’d like to send us a zipped SVG file for a sanity check, we’d be happy to look at it as well.