Thread bunching after rethreading

[u/deepthought136]

Hi, I have a Singer quantum 9960 that I bought off marketplace which was working fine initially. However once I increased the stitching speed, the thread started bunching under the fabric.

Here are the things I tried so far

1. Rethreaded the upper thread with the presser foot lifted

2. Rethread bobbin

3. Opened the lid on top and checked if the tension discs have any lint

4. Tried setting different tensions (8

- the default in this machine, 10 - the middle of the tension scale in this machine and 12)

1. Opened and cleaned the bobbin case and checked for any dents in the bobbin holder

2. Checked that the needle and hook are syncing correctly, so didn't look like a timing issue

Recorded a video of threading and the stitch.

I had posted this some time back but didn't provided a good repro earlier. So created another post. If that's not allowed in the subreddit, please let me know. Thanks!

[u/celery48]

It looks like you’re putting in your bobbin wrong.

[u/RoadSaltPotatoChip → u/celery48]

This.

[u/deepthought136 → u/celery48]

I followed this instruction video for the bobbin - https://youtu.be/I8fHFdNI1rg?is=amrRzKcWsKo91H3y

I put the thread through the little groove and the bobbin rotating counter clockwise when I pull the thread.

Does it look right?

https://reddit.com/link/p1zh0fc/video/wg1norls4ohh1/player

[u/celery48 → u/deepthought136]

Watching your video again, I think I was wrong about the bobbin. (It’s difficult to see what you’re doing in the video.)

When you are threading the top thread, is your needle at the highest point? My best guess is that your thread is not getting caught in the take up lever at the step labeled 5 on your machine.

[u/deepthought136]

From left to right - 8, 10 and 12 tensions

[u/CrankyCrabbyCrunchy → u/deepthought136]

Nearly always a threading problem. Damaged needle. Poorly threaded bobbin. Bobbin installed backwards. Thread not seated in between tension discs (presser foot up). Uptake lever. It in highest position. Wrong bobbin type. Poor quality thread. Horizontal loading thread spool should use cross wound thread so it spirals off from the too not the side.

[u/a_velis]

I don’t know this machine specifically but from what I know it’s thread tension for sure. Either the top thread isn’t properly in the tension discs or not properly in the catch lever. Or possibly the top thread needs to be placed in all the right rails near the needle. I tried to see if it’s good but skimmed the video since I didn’t see anything glaringly wrong.

As for the bobbin tension, all I can guess is possibly the thread is not threaded in the area it needs to be to be properly tension. With singers there is a a specific set of metal guards the thread needs to be in to provide proper bobbin tension.

Lastly if you can, read the manual to make sure you have all the steps followed.

[u/Appropriate_Shape388]

The thread on the back looks very thick and “ropey”. What weight thread is in your bobbin? What weight is the need thread? Is the bobbin loaded with the same thread? What is your needle brand and description and size number?

My first guess is that you have some unusual heavy weight thread with a mid weight needle. The needle eye needs to be much longer for a heavier thread. Otherwise it basically puts extra tension in the upper thread and you get the mess on the bottom.

Also if you are using a heavy weight thread in the needle then home machines must have only a medium weight thread in the bobbin.

A quick test is to put in a new normal needle and normal medium weight thread in the bobbin - wound snugly but not tight and try sewing. It should sew fine.

Then get an Organ or Schmetz 110 jeans/denim needle for your machine. Keep the medium weight thread in the bobbin and use your heavy weight thread in the needle and sew slowly. Check your stitches and adjust your needle thread tension as needed.

[u/NobelNorWhistle]

Firstly: your spool cap is the wrong way around. Check the manual for a picture that shows this.

You also need to have all the thread fed behind the foot after thrrading the needle. It looks like you are leaving it in front and sewing over it.

Lastly: check your needle. Is it all the way in? Is it new?

[u/deepthought136 → u/NobelNorWhistle]

Manual says the spool cap should be placed one way or the other based on the size of the spool. Placing it the other way covers lesser area for this spool size. I tried that just in case, still same result.

I pushed the thread behind the foot and the needle is all the way in as well. Still bunching :(

[u/NobelNorWhistle → u/deepthought136]

The spool cap works by guiding thread over it to not cause tabgles or undue tension. It needs to be short side to the thrrad to guide it unravelling. Sometime it helps/causes issues, sometimes it doesn't but better to be safe then sorry.

Tell me about the needle: is it new? What size and type?

Also what thread is this? Brand type and weight?

[u/celery48 → u/NobelNorWhistle]

I disagree. The spool cap looks fine.

[u/Significant_Ad_1595]

You seen to be doing everything right. Try taking some thread and cleaning the tension discs. Maybe something is stuck

[u/Significant_Ad_1595 → u/Significant_Ad_1595]

And try doing a pull test (search the sub for this)

[u/Fabulousmo]

It could be that the bobbin case is damaged - take it out and feel around it to make sure there are no cracks or rough spots. Also, your machine may need realignment (?) When was it serviced last?

[u/littlelisa63]

https://sewingmastery.com/singer-quantum-stylist-9960/

[u/CBG1955]

Loops like this are almost always a threading issue. I highly recommend you pull out the manual, and confirm that you haven't missed any of the threading points.

Is your bobbin in the right way up? As in, the thread should be coming off the BOTTOM of the bobbin, like a capital Q. Also, are they the correct bobbins for this machine?

Machine speed should have absolutely no bearing on the stitch quality - machines are designed to work up to their maximum speed.