Troubleshoot a Change in Sewing Machine Tension

A student recently emailed to ask:

I bought a M7 in April. My tension was perfect I didn't have to adjust the tension. Now after 51 hours of quilting my back tension is loose. I have to put it on 3.8 is this normal? I sew on a HP foot

Fine Tune that Thread Tension

It totally can be! The auto tension is just a starting point, especially if using different threads or certain stitches. For instance, the machine will increase your top tension if you set it up through the applications menu for free motion quilting. But if I decide to use a thicker thread than usual (ie: switch to 40wt Aurifil instead of the 50wt I piece with) I might not need the top to be tighter. A slippery, high-shine embroidery thread paired with a spun polyester might not react the same to the tension setting that works great for top and bottom of the same type of thread.

Troubleshoot that Tension Change

Specifically, you are using the HP foot, which means you are just doing straight stitch. You've said your top tension is loose, so that tells me you were seeing bobbin thread on the top and so you reduced it to 3.8. Sometimes needing to loosen the top tension on your standard thread combination for a commonly used stitch, like the straight stitch can indicate that the machine has some lint build up in the tension discs, making it harder for the thread to go through....hence the need to decrease tension. Frustratingly enough, sometimes a wad of lint will cause a lack of tension.

If you consistently find that the tension needs to be changed about the same amount each time, you can go into your settings and change the master tension. On these all digital machines, the numbers tend to be lower for tension than on our more manual Janomes which tend to run at balanced tension on regular sewing thread of 3-4-5, with 4 to 4.5 the most common for most regular sewing threads.


Lock the M7 before threading

Lock that Sewing Machine

Additionally, make sure you are 'locking' your machine for threading. This is something that machines like yours with the automatic presser foot lift must do when threading the top. (Janome 15000, 14000, 12000, M7, M17, 9400/9450, S9 and S7. I'm sure other brands with this kind of system have something similar) It tells the machine to OPEN the tension discs so that the thread can go between them properly. With the automatic presser foot lift being controlled by an electronic servo motor, the traditional link between the presser foot lever and the tension discs isn't as direct as on a simpler machine where threading with the foot up opens the discs. While an extra step, it is totally worthwhile.

Preventative Maintenance for your Sewing Machine It could also be time for a service. 51 hours doesn't seem like a lot, but it actually is! That is actual sewing time. The difference between hours on and time sewing can be ridiculously different. All depends on how you sew. Having bought in April, you are coming up on your 1 year anniversary. A service person can adjust the tension manually, so that it is balanced, without you having to change anything.

Self-Care for your Sewing Machine

Also, if there is lint in the tension springs of the bobbin case, that can cause the bottom tension to be loose. Here's a video that covers this issue below.


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Adjust the Bobbin Tension?

Finally, any changes you make to the bobbin case tension will also affect the top tension. It's a balancing act. Typically, we can get a good balanced stitch by just adjusting the top tension. Using 12wt or larger thread in the bobbin call for loosening the bobbin and 80-100wt thread calls for tightening the bobbin. Otherwise, the top can balance it.

Find Janome Education in the AmyQuilts Clubhouse

Want to learn more about your higher-end Janome machine so you too can learn to use it with more creativity and confidence? Want to know how to use all the "bells and whistles?" Check out the AmyQuilts Clubhouse program. Divided into one for sewing and one for embroidery, it's a monthly membership program with a ton of lessons and access to me as a "virtual Janome dealer."

Best wishes for happy stitches,