Ah Miriam. Your Phoenix pics posted here instead of on the Phoenix thread. Yeah, I spend too much time here. I am wondering if the Phoenix wants a very tight bobbin tension? Sort of like the Necchi Lydia I am fighting with. I have the same problem with Naughty Lydia, beautiful top stitch with big loopys and the bobbin side. She is currently in "time out" under the sewing table till I figure out how to correct her tension issues.
Wow, look at that drive belt underneath. Yep, those girls are "iron maidens" for sure.