Sounds like the screw is stripped. A visit to repair many less you know how to take the screw fixture off and replaced. I worked on a friend's singer the other week which was missing stitches and not sewing correctly. After altering to correct place all the tensions I went to take the needle out to replace. The gentleman who had borrowed the machine had jammed the needle somewhere, definitely not the right place. After removing needle and putting a new one in correct place the machine purred.

This is my experience with needle falling out of my Brother ULT....I had difficulty with it jamming and could not remove without pliers. So I removed the needle screw completely, turned the machine over to have a close 'look see'. When I put a new needle in and the screw, I could not sew because the needle kept falling out. I took it to repair and was told a part was missing, which I denied could be the case. He was not associated with Brother co. and could not order. So I returned home and placed my machine back in it's spot. Aha--there was a strange looking item behind the machine. It looked like a nail with the head cut off. This pin goes into the screw hole before replacing the screw. Sure enough, "a part Had been missing"! I think the point goes in first, but I reversed it and have never had a problem since. This is my primary embroidery machine, so you know how fast the needle penetrates fabric. Could you somehow have lost that little pin?

My walking foot also tends to loosen the screw that holds the needle. Keeping the screwdriver handy and tightening it every couple of minutes is all I can do.

My guess would be that the motion of the walking foot is enough to loosen that screw that holds the needle in

That's one of the reasons I sold my BL E. It drove me crazy! I quit using the walking foot and used my Bernina to quilt. Every time I took it to be repaired the tech would tighten it, but it never lasted.

Not often but the vibration can cause things to loosen. i check every once in awhile.

Oh yes, my bl has a similar problem....but it's the screw that hold the foot in place......to replace that "part". .....$100+.... No way! I'll buy another kind of screw.... So sad, pay big bucks for poj!

Mystery Solved!! I have a Brother LS-1217, and had same problem with needles falling out when using a walking foot. Then I discovered the Needle Clamp screw (which holds the needle) is actually too short to use with special presser feet such as a Walking Foot. At "SewingPartsOnline" I purchased a special longer Needle Clamp for $3.99 ("needle clamp attachment screw #SKL-1) I had really pulled my hair out trying to solve this.

Wonderful sleuthing!

Replying to Laynak re needle falling out. Your question is a bit old, and I'm new here and unsure of how all this forum stuff works, so I don't know if you'll see this. I, too, have that same problem with a walking foot and/or FMQ foot. Someone mentioned a longer needle clamp screw. They are not easy to find. The last time I checked, SewingPartsOnline no longer carried them, but it might be possible to still find one somewhere out there on the internet. I have the longer screw, but that did not solve the problem. Recently I decided to try wrapping a little bit of waxed dental floss around the threads of the screw. I was able to use the walking foot with no problem. I kept checking the screw, but it never loosened. In the past, the needle would fall out after only a few inches of sewing! The floss might be worth a try. If you came up with a different solution, might you share it?