I have the Sapphire 855 and I love it but it is very picky about thread. I can piece with just about any kind but it just won't do machine quilting unless I use a good quality cotton quilting thread. Mine has the built-in pressure sensor so I do not have to use a walking foot and I do not need a 1/4" foot as the machine adjusts to a 1/4" by moving the needle. I would certainly take it back to the dealer as this is not the norm for a Viking.