I'm trying to make large rope for the main and fore stay. I'm using Serafil Tex70. I had already made the mainstay and it seemed to have spun up nicely. It is 3 strands of 6 threads. I then spun up the fore stay, it is 3x5. It worked fine. As I held it up to the mainstay I noticed that I had spun the mainstay the wrong way, it was S instead of Z. So I started to spin a 3x6 Z rope as replacement. It won't work. I get knots in what looks like one thread of each strand. It knots up as I'm putting in the first twist, like before I run the bobbin down. I tried more tension in the moveable head and that didn't work. I double checked to make sure all the threads were the same length and all the threads are hanging in nice compact bundles before I start spinning. So in a nutshell what I've got is, 3x5 Z works fine, 3X6 S works fine but 3x6 Z knots up. The Serafil thread comes with a Z twist so I know that I have to untwist to twist a Z rope but it works with 3x5 Z. Anyone have any similar problems?