Thank you for responding. The problem is that lifting the presser foot does not free the discs of the tension unit, so the thread tension prevents removal of the material. I can see that the plastic spindle at the rear of the tension unit has broken off. I plan to remove the tension unit and fit a new one,but it is not obvious how to do this.My wife has dementia and I am her full time carer,
( doing the sewing repairs) and I cannot leave her to make a long journey to a repair shop. I am a mechanical engineer and consider myself capable of doing the repair but consider it advisable to seek some instruction to avoid the possibility of causing further damage. Please help me if you know how to remove the tension unit.
robert
March 2009