Things You'll Need
Thread snips or sharp scissors
A serger is a valuable tool for the modern seamstress. Most sewing aficionados find that they no longer want to sew without one once they are used to the many benefits of this handy machine. It can, however, be intimidating to thread your Bernina serger. Luckily, Bernina makes this process as easy as possible, including color-coded thread paths to assist you in learning the proper way to thread your Bernina serger. Most of what you need to accomplish this task is included in the Bernina serger toolbox that came with your machine.
Number each thread path, starting at the left of your Bernina serger. The first thread leads to the left needle and the second to the right needle. The third thread path goes to the upper looper, while the fourth thread corresponds with the lower looper. If there is a fifth thread, it is the thread for the coverstitch function on compatible machines. You will thread your Bernina serger in the following thread number order: 3, 4, 2,1.
Pull up the metal thread guide from the telescoping rod that sits directly behind the thread holders on your serger.
Place a cone of serger thread on each of the four thread holders and clip each end with your thread snips or sharp scissors.
Turn off the Bernina serger and open the front of the machine by pushing the cover slightly right and then pulling out toward yourself.
Lift the presser foot.
Grasp the No. 3, or upper looper, thread and pull it upward toward the clip in the thread guide rod that sits directly above the spool. Pass the thread through the clip from back to front.
Pull the thread downward from the guide rod. Pass it through the metal guide clip at the back of the serger and directly in front of the thread holder that you are currently working with. Grasp the thread just below this clip and pull the thread downward and into the thread tension knob.
Follow the color-coded path and place the thread into the series of thread guide clips that travel down the machine and behind where you opened the front cover of the Bernina serger. Two of the clips are directly behind the cover, while one is attached to a metal arm screwed below these clips. The final clip is located on the stitch finger that moves up and down when you turn the flywheel of the serger.
Grasp the end of the thread with the tweezers and place it through the hole in the upper looper eye. This sits directly above and to the left of the last guide clip and points toward the left of the machine.
Pull several inches of the thread away from the back of the upper looper eye and under the presser foot.
Repeat steps 1 and 2 in section 2, using the No. 4, or lower looper, thread that sits to the right of the previous thread.
Draw the thread downward and into the two thread guide clips on the correct color-coded path and to the right of the previous thread path. Place the thread into the same clip that holds the upper looper thread, located on the arm screwed toward the bottom of the machine.
Locate the next thread guide, to the left and slightly beneath the previous clip. Hook the thread in that guide. Push down the lever that is on the bottom of this piece of metal to reveal the thread guide hook. Pull the thread into that hook from left to right.
Locate the sideways V-shaped and grooved lower looper eye that points toward the right of the machine. Grasp the thread end with the tweezers and place it in the hole. Pull the thread over the already-threaded upper looper eye, under the presser foot and toward the back of the Bernina serger.
Raise the lever that was lowered in step 3 of this section.
Repeat steps 1 and 2 of section 2, substituting the second thread.
Pull the thread to the left at the bottom of the thread path, cross the first thread channel and then pull the thread directly upward and into the needle thread channel.
Pull the thread left at the thread path channel, bring it downward and hook it into the clip directly below the inverted U-shaped thread channel path.
Clip the right needle thread into the flat needle guide directly above the right serger needle. Grasp the end with the tweezers and slip the thread into the eye of the right needle. Pull the thread toward the back of the machine.
Repeat steps 1 to 3 of section 4 with the first thread on the Bernina serger.
Place the thread into the left-hand side of the flat needle thread guide directly above the left needle.
Grasp the end of the thread with the tweezers and feed it through the eye of the left needle. Pull the thread toward the back of the machine.
Sew several inches of serger tail, with the presser foot down, once the Bernina serger is properly threaded. To avoid completely rethreading your Bernina serger, loosen the tension, trim the thread directly above the thread path, tie on the new thread and gently pull it through the entire thread channel. Return the tensions to their correct setting. Thread the serger with a color that matches the color-coding on each thread path when you are first learning. This will allow you to better identify each path and troubleshoot problems. Different models of Bernina serger may vary slightly, but the process should be similar among all models. Follow the color-coded path if there is any variation.
Keep your fingers away from the sharp needles while threading your Bernina serger.