Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Quality control is an issue

The first one of these sharpeners that I bought worked wonderfully. The only complaint I could make about it was that the shavings tray is very small, and if it got overfilled it was very difficult to pull out and could break.But when it came time to replace it, my second one's blades were clearly off center, because no pencil would sharpen evenly. The whole unit would shake and rattle too. So I returned it. The third one also had a similar off-center problem, and to make matters worse, as soon as I inserted a pencil it would never shut off again until I unplugged it.After that, I gave up and went with another brand.