I've recently started using a sewing machine to make simple cushion covers. But I've run into a consistent problem of bunching. Below is an example of what I'm experiencing:
I've checked that my feed dogs are up, that the tension is on, that my bobbin is in the correct way, and that the upper thread is correctly threaded. Is there any other issues I should investigate before getting my machine looked at?
Are you absolutely sure the upper thread is threaded correctly, especially through the tension control knob? (I would go ahead and re-thread the machine, since it's cheap to do.)
Other things to make sure of (most of which you've already done, but just for completeness' sake):
Also, something that helped an old finicky machine I used to have was to clean out the bobbin area - the accumulated fuzz seemed to make it more prone to tension issues, somehow.
If none of that helps, I'm afraid it's time to visit the repair shop.
One fix to attempt before taking the machine into the shop is replacing the needle. A slightly bent needle can appear to be sewing correctly, but once you start going at speed it almost inevitably creates one of those nasty tangles.
Any time I've had that problem, the bobbin was inserted in the holder the wrong way. What seemed like the right way was the wrong way.
Another thing you might check is for knotted threads jamming the bobbin area. This happened to me after having consistent birdnesting on my piece, after checking the tension and upon removing the bobbin to check it and noticing the gigantic mess.
I've checked that my feed dogs are up, that the tension is on, that my bobbin is in the correct way, and that the upper thread is correctly threaded. Is there any other issues I should investigate before getting my machine looked at?
So as to not be redundant, since you've checked most of the stuff that would go wrong first I suggest the following:
Needle point is important, be sure when sewing wovens you are using a needle with a sharp point (knits use ball point). The size of the needle is crucial. The weight of the thread may be too thick for this woven fabric.
The bobbin tension with this thread could be part of the issue. Try a different thread in the bobbin and topstitch with the thicker thread. Sometimes that's a good workaround for thread thickness. Different machines have the option to adjust the tension on bobbin casings.
Clean the bobbin holder and the entire bobbin area - no lint whatsoever. Test the machine with this thread and needle using muslin. Is this happening with other woven fabrics and other thread? If so, the timing is probably off. A tune up would be a good way to go.
It will take some trial & error, you need more top tension. Period. I don't usually mess with bobbin tension. Only let a machine expert do that!
Each type of fabric may need different, I usually take a couple 2" strips of the fabric and sample run, until it is the way I want it!
Read your manual... but my manual for my 1892 and 1926 Singer machines, each a different model. Say but one thing. Too much thread tension.
Bobbin tension is one thing that hardly ever need attention.
Both manuals showing graphics much like your photo.
The best solution I have found, other than comments read here, is through a UTube video called '5 quilting tips I wish I knew', by National Quilting Circle. It's not about quilting, but it's about the machine, tension, thread, etc. I am not affiliated with this group, but the information changed things for me in a good way. I love my machines now. PS -use the cup for the cross wound thread and use the sewing machine bar, if you don't have one, buy one, it's worth it! You'll know what I mean after you watch the video. :-)
