In Janome embroidery machines, the upper and lower thread tensions are set so that even stitches are formed when sewing. However, these factory presets are created assuming that equal thread weights will be used in the top and bottom threads. If using different types of threads, these presets can cause stitches to become uneven. In that case, adjusting either the top thread or bobbin tension is necessary. Technicians can do this in the store, but it is easy to change the bobbin tension at home.
Locate the tension screw and place a black dot where it is pointing. This will enable the screw to be returned to its original setting.
Using the included screwdriver, make a quarter turn either counterclockwise or clockwise. Counterclockwise turns will loosen the tension, and clockwise turns will tighten the tension. Most of the time, loosening the bobbin tension works best.
Pull the bobbin thread and the top thread through the needle. There should be very little tension when pulling the threads.
Using a material scrap, test the new bobbin tension with a simple embroidery pattern to determine whether the stitches are even. If the stitches are even, return to your embroidery project.
If the stitches are still uneven, repeat steps 2 to 4 until the machine makes even stitches.
• Always check the top thread tension first because it is easier to adjust. • A small adjustment to the top thread may be needed after adjusting the bobbin thread. • The bobbin case should never lift from the palm of your hand when you pull the thread. • Cotton batting will drag or pull the top thread more than poly batting, so try changing the type of batting before adjusting the bobbin tension. • If using a metallic or heavy cotton top thread, a silk-type filament poly bobbin thread will work best. • Using different fiber or weighted threads is fine, but tension adjustments must be made when threads are not equal.
• If bobbin tension is not changed properly, for instance making a full turn rather than quarter turns, the case could clog with thread or break a needle. • Not marking the original setting will make it difficult to return the machine to the factory presets, meaning that each time the thread is changed the bobbin tension must also be changed.