As others have said, you're probably dragging your needle as you move your quilt, so that it hits the needle plate. Needle size is usually determined by thread size - 50wt thread, 80/12 needle - 40wt thread, 90/14 etc. I like a quilting needle, but sometimes use a Topstitch.
Some people have suggested using Titanium needles, but as you'll see from the picture below, they'll still hit the needle plate if you drag your quilt (time I practised what I preach, lol!). It's more a case of arranging good support for your quilt and trying not to go too fast when you change direction. Good luck
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