Boston1954

The needle shudders, and sounds like a jack hammer. I cleaned the insides, changed the needle, checked the owner's manual and the only other choice is the bobbin case may be scratched, although I cannot see it.

Has this happened to you? Is there something else I can do?

Boston1954

Well Jim came in an watched as I attempted to sew. It is not the bobbin case. It's the motor. If Jim cannot get it fixed, I will be doing something else for a while. I have no backup machine. Please keep your fingers crossed for me. Cannot afford a new machine just now.

Dolphyngyrl

I have never had that problem with my SQ-9050 maybe it needs servicing and something inside needs oiling

Prism99

To confirm it's the motor, you can try running it without a needle (and even without a bobbin). Jack hammer is not a normal sound for any sewing machine!

ManiacQuilter2

You might just start looking around in 2nd hand stores and garage sales and pick up an older reliable backup DSM. I have always had to take my Bernina for yearly servicing just like a car.