I switched to the treadle machine, because the modern machine was actually catching the underside of the hourglass blocks and tearing the fabric while i was sewing, and the treadle has a flat, smooth stitch plate without all the fancy holes and openings for attachments that are tripping me up on the modern machine. It is only one fabric that rips, and I have just been completely disassembling the block to replace that piece, then reassembling. I am about to run out of it, though, so I have to be very very careful with the last few blocks I have using that particular shade of gold. It took me a lot of experimentation and redoing blocks, but I found the right combination of pins and ways to put the units through the machine to minimize the risk of the fabric catching on anything.
I also have decided that as long as it isn't glaringly obvious from three feet away, I am going to have to live with points that don't quite add up...the problem has consistently been with one of the gold triangles on the hourglass units coming up a smidge small every time.
No more quilt kits for me unless I know what fabrics are in them first, this one has only a couple of quality fabrics, and a couple that are so thin they tear like tissue paper with the slightest pressure. I had this problem earlier with one of the oranges, but the fabric damage was always at the edge of pieces in what would get turned under t he seam allowance.