Wait...you're supposed to change a needle after just 12 hours of use!?
I know I tend to wait too long (often I only remember to change it when it starts to sound "poppy") but I didn't know there was a 12 hour guideline. I TRY to remember change mine between every other quilt, which is probably a lot more than 12 hours of sewing for me. Or I'll (carefully & VERY gently) run my fingertip over the end of the needle if I can't remember when I changed it...if it catches on my fingerprint I figure it's still sharp enough to use.