Seat base/bed cushion torn underneath.

We have had an issue where the underside of the seat/bed cushion has been trapped and torn on the slide-bearings when making up the beds; this has been caused by sharp edges on the end of these slide-bearings, catching on the fabric and eventually wearing right through to the foam. I've fixed it today by removing all the sharp edges with a file (not easy, as some of them are underneath) and by sewing in a piece of canvas to cover the torn material.

If I could get the servimg link  image upload software to work, I'd post the photos!