Originally Posted by 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?

Originally Posted by Ncb607

I am having the same problem and have been since buying my MC 15000. I just got it back from service last week and the bobbin case jumped again last evening. Mine was bought from dealer used but I have noticed what looks like a crack in the white part under bobbin holder. I use ONLY Janome bobbins and have found a new bobbin holder seems to help for awhile. It has never done it during embroidery which uses a special bobbin holder. What did you do about your's?

Originally Posted by KalamaQuilts

old thread, fun that the OP responded! My first computerized janome went through (MC9000) 3 bobbin cases in it's lifespan, That would have been the first thing I would have suggested. I have a Janome Horizon now, and occasionally the bobbin itself will bounce when it is getting quite low on thread, but not always. But when I do hear that I fresh bobbin always cures the problem.

Originally Posted by gardengirl1331

Well I just bought a couple new bobbin cases. I got a very small bit of money when my great aunt died, enough to cover the rest of the cost of a 6650 with what I had saved so far, and I don't like it at all. Had an issue with the foot pedal which seems fine now with them replacing it. I've been trying to sell it locally but no one is interested, too bad this didn't happen during COVID I probably could have sold it for almost what I paid for it instead of trying to unsuccessfully sell it at $500 off new when it's only a few months old. But I just can't bond with the machine at all and I'm back to my 6300. The bobbin is still a little wonky, but now I just deal with it, when it gets really bad I'll just put in a new case. I have no clue how the white part got scratched since even at it's lowest point the needle is no where near it, and how would it have gotten through the bobbin case? I do worry I'll need a new machine at some point, which I'm not sure what to do when it happens. I love quilting, but my health isn't real great and it's getting harder and harder to do some things, so I'm not sure if I'll quit, or go to a real cheap "crappy" machine to save money and just deal with that, that way if something happens I'm not out a ton of money like this last time (I don't have any shops near enough to me to go really test much out, aside from Joann's which only has the basic singer models. Or any repair shops locally either since the guy I brought this to I told him about what everyone here told me about the bobbin case and asked him to order me one to test it and he never ever got back to me!! So I was out hundreds of dollars in "repair" work that never really happened it was only barely cleaned (and he didn't oil the wick since it was super dry when I got it back!) when all it was was the bobbin case needing replacing!)