• During the use of commercial sewing machines, tension is the decisive factor that determines the quality of your embroidery. What is tension? Tension is the pressure exerted by the machine on the wire. You can make adjustments on the machine depending on the fabric or thread you're using, or even the complexity of the design you're using.

    Adjusting the tension on a commercial sewing machine is critical to obtaining correct seaming results. Tension adjustment ensures that the upper and lower threads are balanced for even and strong stitches. Always refer to your machine manual for exact instructions.

Here are some tips on how to adjust the tension on your Smartstitch commercial sewing machine:

1. Understand the tension system: Commercial sewing machines usually have a tension assembly, which consists of a tension disc, a tension regulator and a tension spring. The tension disc fixes the upper thread, and the tension regulator adjusts the tension by controlling the tension of the upper thread.

2. We use the "I" test to test for tension. Basically it's a one inch post of satin stitch. Now we turn it back and compare the bobbin to upper thread ratio. Ideally, you can see a third of the top line run along the sides, and then a third of the bottom thread run down the center.

3. Thread the machine: first thread the machine correctly. Make sure the upper thread passes through all necessary guides, tension discs and needles.

4. Check the bobbin thread: Make sure the bobbin is threaded into the bobbin case correctly and goes in smoothly. Improper winding or insertion of the spool can cause tension problems.

5. Set the correct tension for the machine: Before making adjustments, determine the appropriate tension for the fabric, thread, and bobbin thread you are using, and set the flexible tension according to the specific embroidery needs.

6. Test on scrap fabric: Use scrap fabric similar to the material you will be sewing. This will allow you to see how adjustments affect your stitches without ruining your actual project.

7. Upper thread tension adjustment: To increase the tension (tighten the upper thread) or to decrease the tension (loosen the upper thread). You can gradually make small adjustments and test the stitches on scrap fabric until you achieve a balanced stitch.

8. Bobbin thread tension adjustment: If the upper thread loops excessively on the bottom of the fabric, you may need to adjust the bobbin tension. Make small adjustments again and test the stitches.

9. Balanced tension: The goal is to achieve a balanced stitch where the upper and lower threads meet in the middle of the fabric layers. Balanced stitches look the same on both sides of the fabric, with no loops or knots.

  • 10. Check Stitch Varieties: While adjusting the tension, test the various stitch patterns, lengths, and fabrics you plan to sew. Different fabrics and stitches may require slight adjustments in tension for best results.

    11. Regular machine maintenance: Keep commercial sewing machines clean and well lubricated. Dust, lint and debris can affect the tension mechanism and overall seam quality.

    12. Practice and Patience: Adjusting the tension will take some practice, especially if you are new to sewing. Be patient and keep experimenting until you are satisfied with the results.


    Keep in mind that each Smartstitch machine is unique and it may take some trial and error to find the correct tension setting for your particular sewing project. If you're not sure whether to make adjustments, consider seeking guidance from a sewing machine technician or someone knowledgeable with experience in sewing machine maintenance. Please actively contact us, Smartstitch is always at your service.