You should change the needle about every 8 hours of sewng time. Not to say that it won't work after that, but if you could see the tip magnified, you could see that the tip was getting worn and will affect its performance. So if you want the best from your machine, change the needle as advised. And clean the bobbin area, pop off the neele plate and clean at LEAST after every project, and ideally at every bobbin change. These are such little things that will keep your machine running more smoothly.