Quote Originally Posted by m_c View Post
Sounds like a USB lock up issue due to interference.
Try a good quality USB cable with ferrites at both ends, or an opto-isolating USB cable. You've not said what kind of spindle you have, but it could be worth adding some noise suppression to that, as it's most likely the additional current under load that is causing the problem.
You are right, I found a shorter shielded cable and it worked far better, I only had a freeze one more time after like 20min. I'll probably replace the wires with shielded ones and get a even better USB cable in the future but for now it works!