gardengirl1331

I bought my Janome MC6300 in 2014. After working on some real thick masks last spring for the local hospital (4 layers thick with pleats plus elastic, it wasn't happy, I went very slowly but the machine just didn't want to do it at all the repair guy said it should be able to handle that thickness which much issue) the bobbin case starting bouncing around while sewing. It happens more when going a little faster (I keep the machine set to the middle range for speed on that switch and don't ever go super fast), and gets worse the closer you get to the end of the bobbin thread. I took it in to get cleaned and serviced last fall, and nothing changed. I took it back in a month or so ago with telling the repair guy exactly what I wanted looked at. He said there are grooves in the area under the bobbin case (is it called the hook race?? I'm not sure? It's the white part where the groove is) from me possibly not getting the needle up in far enough (he said even a 1/16" difference can sometimes cause problems) In the last 7 years I've only broken 2 needles, both with denim and in both cases the tip had to be pried out of the fabric, it never got lost in the machine. I clean the machine after every project, sometimes during if I think it's more linty than normal, when he cleaned it this fall he was surprised at how clean it was since it was it's first time in the shop in 7 years. I was using schmetz needles, he told me to switch to superior threads, and coats and clark thread which he told me to try the aurifil. Both changes have given me better looking stitches, but the rattle/bouncing still is happening. It's threaded by the machine, it's threaded through the machine the right way as well, the last time I dropped it off he told me to not touch anything on the machine and leave it as it is, and he said it looked fine in those regards. I'm just not sure what is wrong, and I assume he doesn't know either or it would be fixed. I can hear it happening too, it gets louder and makes a rattling noise and when you look while sewing when it doesn't make that noise it's all nice and smooth looking, and when the noise starts you can see the whole bobbin case rattling up and down. I assume he oiled the wick, I do plan on buying oil for it next time I'm somewhere that sells sewing machine oil so I can put a drop on the wick occasionally. When it does this it just makes noise, it doesn't mess up the stitching or anything else. Could that groove cause this? And if so couldn't he have just said it needs to be replaced and be done with it? What else could it be? Besides this issue I love this machine, but now I'm wondering if I should get a new one and keep this as a backup only. I only have the one machine so not having it while it was in the shop was hard. But looking at the prices of new machines, wow! I can't afford to do that right now, I'm already saving for one, but they are so much more than this one was in 2014! Like almost double the price in just 7 years for the next model up, I assume the next model, I can't figure out Janome's numbers?! I like the large throat, and kind of like the idea of the 6650 over the 6500, but it'll be a little bit before I could afford that. My local guy also sells the Elna machines more than the Janome, which I might look into, but I really like the looks/specs of the 6650 so far.

Anyone have any idea what the issue could be?