Bobbin case on Janome problem
 

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?

Have you tried prewound bobbins and does that make any difference? Is it sometimes better and sometimes worse? One of the last options we consider is it is a bobbin issue itself, not the casing or the thread or the mechanics, but a tiny little rough edge or ever so slight bend..

The Bernina I have has a proprietary bobbin and that isn't an option -- but maybe your technician already tried/can wind a bobbin for you to try.

My friend's long arm was terrible about bobbins, we tried everything we could and then finally we started buying them via Superior Threads and life immediately got a lot better.

That same friend had a reasonably nice Brother and then got a nicer Brother embroidery machine and while they looked and fit fine to the naked eye, the bobbins were just so slightly different! Finally, she got rid of every bobbin she had and bought new ones, putting a permanent marker line on the embroidery bobbins. Again, life got better :)

Another thought and I know it sounds silly -- what is your work surface? Another friend of mine just had such terrible results and I knew she had the skills needed -- when I visited for a sewing day it turned out she was sewing on a flimsy card table that bucked up and down like a bronco while she was sewing. We bought a prefinished shelf board at the local hardware store and put that under the machine and just the bit of extra stability helped both machine issues as well as technical skills and was still easy to take up/down.

On my old Viking D1 I plain and simple wore out some of the parts and it got noisy....the dealer was able to replace them. On my older Bernina, it was getting noisier but stitched OK. I think with newer machines then pre 1950 or so....the parts are not made out of the metals the old singer's were and they just get worn. I am creaking more these days too.

Are you using Janome bobbins?? My 6600 only work with Janome bobbins

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My repair guy told me to only use plastic bobbins on my Janome.

At the shop, I see this all the time with drop-in plastic bobbin baskets. They just don't handle thick fabric. It's probably just fine while sewing two layers of cotton fabric. Right?

Check the bobbin basket for damage. You can polish any needle holes or scratches with a very fine sandpaper, about 400 - 600 grit. It only takes a few strokes, so be gentle.

The other thing that happens is the spring in the front can get damaged. Sometimes it needs to be bent back into shape or replaced.

One other thing that happens is the "finger" that holds the bobbin basket position gets bent upward. Most can be pushed back down with your finger. The metal is pretty soft. Some fingers are in the needle plate, and can also be adjusted.

There needs to be a small space between the bump on the front of the bobbin basket and the spring in the front, for the thread to pass through, so don't tighten the space too tight.

Your bobbin case may just be worn out and needs to be replaced. The Janome bobbin cases are about $35.00 and are available in a lot of places. Attached is a link to Sewing parts online that gives some practical information about bobbin cases.
The first thing I would do is replace the bobbin case itself, or get your repair guy to try a new case in it to see if that is the problem.
https://www.sewingpartsonline.com/bl...e-bobbin-case/

OK, let's see if I can get to everything here (and thanks so much everyone!!)

I was using a mix of bobbins I bought that were said to be used in Janome machines and a few Janomes that came in the package with my machine, but after the checking the machine last month he said to use Janome bobbins only, so that's what I've been using since then. I do also check the bobbins every time I fill them now, rolling them on the table to make sure they don't wobble or do anything weird. They did ask me if I've ever used prewound bobbins and I said no, they never really said if it's better or not.

My work surface is my dinning room table, it is stable when going slow, and moves a bit when I hit one speed, but when I go a tiny tiny bit faster it stops the movement, it's weird, it's only one speed it does this with!

They were going to try a new bobbin case but didn't have one in stock at the time I took it in. I did feel around every single little part of it and nothing has anything that can snag fabric. I'll try to post photos of the damage from the needle on that white area. I did feel it and it's there, but not horribly rough, but thread can't snag down there can it?? The bouncing seems to be the case itself not the bobbin.

The repair guy wants me to take a video of it, but I haven't figured out how to do that just yet. I think I'll need my husband to do it for me since I don't think I can get the right angle with a tripod.

It does this with thick fabric and thin fabric, it does it when going fast (like I said above I don't go super fast since I can't control the fabric when it goes too fast so I have it set to the middle speed with that switch thingy) and yesterday I was trying to pay more attention to when it does it and it does it slow too, not super slow, but what I would call slower average speed. So basically it's doing it all the time no matter what I'm doing. The weird part is when I start sewing it's totally fine, then after going for a bit it starts up. Like if I'm piecing an 6" square it's fine, but if I move to a longer seam, like 10-15+" it starts bouncing. Sometimes I can sew for a full length seam and nothing, then then next one 8-10" into it it starts acting up. I could maybe understand it if it did it all the time, but it doesn't.

Another quick question, like I said above I went from coats and clark thread from joanns to aurifil, and now I'm cleaning lint from the bobbin area about 5 times as often. Is it normal for the cotton thread to produce THAT much more lint?!

Re the Elna machines, they are now made by Janome. I have the 7100 that I use for FMQ, and I love it. I owned several Elnas before the company was taken over...they were my preferred machines. I cannot help w/.your problem as I've never owned a Janome ( unless the Elna 7100 is considered that brand), but I hope you get it figured out.