I do machine quilt my quilts. I protect the quilt from the sharp corners of my machine cabinet with plumbing pipe insulation. It fits around the corners and has sticky edges to keep it in place. See the photo attached. When I have a quilt that's large, heavy, or bulky, this protects it.
As others have mentioned, if the quilt is very large I put card tables around me to hold the weight of the quilt.
Pipe insulation protects quilt from sharp corners of table
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