I just got my stepper motor working. Plugged it into a TB6612FNG and a 12V wall wart for power. Been spinning it like crazy on my desk, reveling in my new accomplishment. However, I just noticed it's quite warm. Not "oh I just burned myself" warm, but too warm for me to just hold comfortably. From what I gather, this is normal. I am, afterall, running current through it constantly. What I don't know is whether or not I should worry about it overheating. I don't have any load on it yet, just toying around with it free-spinning on my desk. Any concerns?