Adjusting the lower tension on a sewing machine, also known as the bobbin tension, involves making very slight adjustments to the bobbin case screw to balance the thread tension between the top and bottom threads.
Understanding Bobbin Tension
The bobbin tension is a key factor in achieving a balanced stitch. When the bottom tension is incorrect, you might experience issues like loops on the top or bottom of the fabric. According to the video reference, you will adjust this tension alongside the upper tension until you achieve a good balance between them.
How to Adjust Lower Tension
- Locate the Bobbin Case Screw: This is a small screw located on the bobbin case.
- Prepare the Bobbin Case: Remove the bobbin case from the machine and ensure it is clean.
- Use a Small Screwdriver: Use a small screwdriver specifically designed for small screws on sewing machines. This will reduce the chances of stripping the screw head.
- Make Slight Adjustments: The key here is to make very slight adjustments. Move the screw a tiny bit at a time and then retest the machine's stitching.
- Tightening the screw increases tension, making it more difficult for the thread to pull out.
- Loosening the screw reduces tension, making it easier for the thread to pull out.
- Test Stitch: After making an adjustment, reinsert the bobbin case and sew on a test piece of fabric to check the results.
- Iterate: You might need to adjust the lower tension in small increments multiple times while adjusting the top tension until you get the perfect stitch.
Important Considerations
- Very Slight Adjustments: As mentioned in the provided video, when adjusting the bobbin screw, you should move it slightly; very slight adjustments are key.
- Record Adjustments: Keep track of how much you turn the screw so that you can return to your starting point if needed.
Troubleshooting
- If the top thread is loose or looping on the underside of the fabric, the bobbin tension is likely too loose.
- If the bobbin thread is visible on the top of the fabric, the bobbin tension is likely too tight.
- If you are unsure, consult your sewing machine manual, as each machine may have slightly different mechanisms.
By making these small, incremental adjustments, you'll be able to find the perfect lower thread tension for your sewing project.
