I used to change my needle when it broke or wasn't sewing well. When I got my Bernina, 10 years ago, I started changing the needle with each new project or after about 8 hours of sewing if it is a large project.

Me too. I did have to change it after I put it thru the side of my finger the other day as that bent it way out of shape. Me too, pretty much. LOL

Whenever I am working on knits or nylon fabric, I put in a new needle & if I hit a pin I change it. Dull needles will make holes or make the fabric run. When I'm working on cottons, I don't change as often as I should. I am cheap & try to get the most out of it as I can. I need to break the habit & start spending a little more on neeedles.

The "rule" is after every 8-10 hours of sewing, advice from a sewing machine dealer, or at least every project, but I change my needle when I notice it isn't stitching quite right, or it starts to skip stitches. I do, however, change the needle when I start to machine quilt, because by then I've spent a lot of time sewing the quilt top or one or two more and it needs to be changed.

Dull needles actually poke holes in your fabric, so you don't want to keep needles for too long, or your quilt will not last as long. I change mine every project, or about 10-12 hours of sewing. You can "feel" your needle to see if it is dull, a new needle feels sharp, and does not have burrs on it. If it doesn't feel sharp, or you can feel bumps along the sides, it is time to replace it.

I think I've changed the needle maybe 5 times in 25 years, and made probably 50-75 projects in that time. (quilts, Halloween costumes, dog coats, etc) I only change the needle when it bends, breaks or gets obvious that it needs it. This isn't about $$$. I just don't think about it. However, I sew with a 1940 cast iron Singer. I'd probably do things differently if I changed machines....which will be NEVER!!!!

Another telltake hint as to when to change the needle, the machine is sewing small zigzag stitches and you don't have it set to zigzag.

I replace the needle when I notice a problem.

I never get it to stay in there that long and with hand quilting. I have 3 1/2 years before retirement.I cannot wait.

I usually change when I do an embroidery.