I change my sewing needles at the first sign of a skipped stitch. My embroidery needles are changed every other purchased bobbin.

My longarm needles I change every 4 queen size quilts (about 8 hours, which is the standard).

Marge

I change my longarm needles with every quilt, but I am a little lax on doing it with my sewing machine. I sew every day and change the needle on my sewing machine about once every couple of weeks....I know, I'm bad :)

I use Schmetz or Inspira microtex 80/12 for piecing quilts, 90/14 for flannel quilts.
For machine quilting: 90/14 top stitch
I change them after every project, sometimes more often.

I like to change the needle when they cause a knocking sound.

Too funny. lol

Thanks for all the good advice. I will watch for joann's to have their 60% off and stock up on them.

I change the needle about every eight hours of sewing, but much more frequently when quilting.

I do try to change mine fairly often. I just inherited my DSIL,s 1985 Pfaff. She has never used. Her hubby did once in a while, and when he passed away she gave it to me. In a beautiful cabinet. We had it services and I was trying it out - sounded really bad for a just serviced machine. So I decided to change the needle. purred like a kitten. She said she didn't think the needle have ever been changed since 1985!! Maybe some kind of record! The needle will definately been changed more than once every 28 years!

What model is your Pfaff? I have two: a 1222E and a 2040

Purplefiend: My Pfaff is a 1222. The only thing missing is the hard cover, as it came in a beautiful cabinet. Of course, the hard cover could be in the attic or somewhere at DSIL. But I can live without it. Hope to give this sewing machine to my Granddaughter later (she is 6 now) and wants to learn to sew.