I am surfacing my new ShopBot and midway into the file I am having the spindle stop moving. The spindle will still be left running. I have to go out and restart my computer to get the spindle to quit running. The window that comes up says "Lost Comm Return". What does it mean. Can that be caused by static electricity? If so my dust collector tube is not grounded. Can I wrap it in bare copper or am I better off to buy the tube with the ground installed? Where can I buy the tube? My second question is when I make the surfacing table file it always will raise the spindle to 1" and proceed to go around the table. I have to edit the file to not raise the spindle and it will then proceed to cut. Why does it raise the one inch?