How to Thread a Juki Industrial Sewing Machine

Welcome! This Instructable will show you, in detail, how to thread a Juki industrial sewing machine. There are a variety of models of industrial Juki machines (older ones, newer ones, etc.), but even if you have a slightly different machine than the one used here, the basic principles will be the same.

I will go through the process step by step. This Instructable is built around the photo-guidelines, which are read left to right, top to bottom. I will write out each step for the different parts of this process, but please refer to the photos for each as they will give you a more concrete idea of what you should be doing/what everything will look like.

Please also keep in mind that once you have these steps down, you don't necessarily have to follow this order exactly. Most of the steps can be switched around a little bit, and you will figure out what order works best for you in time.

Before threading the machine, let's get to know the various machine components and small pieces we will be using to get the machine threaded and ready to sew.

General parts:

1. Hand wheel
   • Allows controlled/sew sewing
2. Knee bar
   • Raises and lowers foot; push to the right using knee and foot raises
3. Top thread holders
   • Holds your thread in place
4. Top threading guides
   • All the little parts that guide your thread along to the needle to create the right amount of tension
5. Back stitch lever
   • Used to stitch backwards/lock off the end of a row of stitching
6. Bobbin winding area
   • Where you will thread the bobbin
7. Foot pedal
   • The foot pedal is GO; it is what makes the machine sew
8. Stitch length knob
   • Adjusts the length of the individual stitches
9. Tension knob
   • Adjusts the tension of your
10. On/Off Switch
    • Turns your machine on and off; some machines will have a switch (like a light switch) and some will have buttons labeled "on" and "off". Always make sure to turn off your machine when you are done using it.

Small Parts

1. Bobbin Cover
   • Flat metal piece which covers the area where the bobbin is installed
2. Feed Dogs
   • Serrated metal pieces that pull your fabric forward as you sew
3. Throat Plate
   • Flat metal piece which provides guides for seam allowances
4. Needle
   • Make sure you have a needle for an industrial sewing machine. Home sewing machine needles that would would purchase at a fabric or craft store WILL NOT WORK.
5. Foot
   • Holds the fabric in place
6. Bobbin
   • Holds the bottom thread; Like the thread, you must make sure that your bobbin is the correct one for your Juki machine - NOT ALL BOBBINS ARE CREATED EQUAL and using the wrong one can damage your machine.
7. Bobbin Case
   • Holds the bobbin
8. Mini Scissors
   • For snipping thread
9. Screwdrivers
   
   • Mini screwdriver (yellow) to install your needle, foot, and ultra mini screwdriver (green) to adjust the tension on your bobbin case

Sewing machines sew with thread coming from the bottom of machine as well as the top. Before loading the bottom thread into the machine, you have to prepare the thread by winding it onto a bobbin. Note: This is the ONLY time in the whole threading process (aside from sewing your sample) when your machine should be on.

Steps:

1. Start by placing the thread color your want on the thread holder. Loop it through one (or both) of the metal hooks above it.
2. Bring the thread down to the bobbin winding area and place the end through the small hole. Loop the thread around the back of the wheel and then towards the front. Pull it tightly so the thread is deep in the groove.
3. Grab your bobbin and place it on the black knob for winding. Push it all the way on (to the left). Push the black metal piece connected to it forward. This will switch the machine from regular sewing to bobbin winding mode.
4. Wrap your thread under the bobbin and then wrap it around the bobbin manually a number of times. Pull the end through one of the small holes in the bobbin and hold it taught off to the right. Locate the on/off switch or button(s) on your machine and turn on the machine. Use the foot pedal to start winding the bobbin - after a couple seconds, the thread in your right hand should break off and the bobbin with continue to wind. Try to keep it at a medium speed. Note: While your machine is now in bobbin winding mode, the needle (if installed) will continue to go up and down, so keep your hand out of the regular sewing area! This is a good general rule, but keep it in mind at this time.

Once the bobbin is all the way wound, the piece that your pushed forward in step #3 will automatically bounce back to its original position. Snip your thread to release it. Your bobbin should be wound tightly and evenly. If it is loose and squishy, it has not been wound correctly and you must re-do it because it will not sew correctly and cause you problems if installed. If it is nice and tight and neat, you've wound the bobbin successfully and are ready to install it. TURN OFF YOUR MACHINE.

Though the bobbin is successfully wound, it needs to go into its case before going into the machine. Once the bobbin is placed correctly in the bobbin casing, it is placed underneath the throat plate, in the underside of the machine.

1. Position the bobbin so that the loose thread is coming from the top, and facing right. This is super important!! The thread cannot be coming from the bottom and cannot be facing left. TOP RIGHT ONLY! Place it in this orientation into the bobbin case. Gently pull the thread through the small slit.
2. Pull the thread gently to the left and slightly back. With gentle pulling, it will slip underneath the thing metal piece behind the slit.
   • At this point you need to test the bobbin tension. You will do this by holding the loose thread and dangling the bobbin case over your hand. With average/correct tension, the bobbin will slowly fall into your hand. If it falls super fast, the small screw on side of the bobbin case should be tightened a bit. If it doesn't fall at all, the screw needs to be loosened.
3. Pulling and holding the little tab on the top of the bobbin case will lock the bobbin into place.
4. Open the throat plate. Look underneath the machine, just under the throat place, and notice the small, bobbin case shaped indentation. This is where the bobbin case goes! While holding onto the lock tab, place the bobbin and bobbin case into the indentation, with the open gap FACING UP. The open gap will align perfectly with the machine.
   • IMPORTANT >>> Once you have placed it in the machine and the gap is facing up and aligned, gently jiggle the case from side to side to make sure it is locked in place!! The bobbin case can seem like it is in, but is not actually aligned. If you start sewing and the bobbin case is not properly locked into place, the needle will most likely lodge itself into the bobbin case and become fully stuck. This is NOT an easy fix, and will require a machine mechanic to fix.

This is arguably the most tricky part of threading your machine, simply because there are so many steps and they must be done in a super specific order. But fear not! I will provide a detailed picture guide for every step.

1. Place your your top thread spool or cone on the top thread holder plate. Bring the thread through the wire guides above the plates. (You can put it through one or both, just make sure nothing is twisted or crossing.)
2. Bring the end of the thread through the small hole on the vertical metal piece on the top right of the machine. You should bring the thread in through the back. Then, from right to left, guide the thread across the top of the small disc attached to this piece. Pull it taught so it your thread is firmly inside of the disc, not just sitting loosely on top.
3. Bring the end of the thread over to the metal piece on the top left of the machine with three small holes. Start from the top and bring your thread down through the furthest right hole. Now bring your thread down through the next hole. Bring it down through the third hole. (This small piece may be in a different orientation depending on your machine, most likely vertical instead of horizontal - follow these steps and you should be able to thread it properly.)
4. Now we get into some of the thread guides that are all right next to each other, so make sure you do everything in the correct order. Pull your thread down towards the disc just behind the tension knob. Guide the thread through the center of the disc (not behind it; check this). While sandwiched in the disc, pull it under, to the left and up, securing the thread in the disc. Now pull the thread down next to the disc and pull it under the shiny metal piece directly to the left of the disc. Now pull it up and under the small metal hook just above the disc.
5. Locate the thread guide with another small hole in it that is directly behind the black handle-like piece on your machine. Thread the end of your thread through this hole from right to left. Pull it down and behind the shiny wire loop location below it a few inches. Pulling the thread tightly behind this loop should situate it in the loop. (See pictures).
6. Right above where you will install your needle, you will see a small black wire guide. (This might not be black on your machine, but it should be in the same location.) Bring the thread behind this wire. The end of your thread should be facing down towards your throat plate.

Now that the bobbin is wound and installed, and the top threaded is threaded through all those many parts, you are ready to install the all important NEEDLE! Note: Double check that you are using a needle for an industrial sewing machine! A size 10 or 12 is standard for medium weight fabrics.

1. Take a close look at your needle. At the pointy end, you will see a small groove that cuts into the needle. This groove is called the scarf. When placing the needle into the machine, the scarf must be facing right.
2. Underneath where the thread is hanging is a small hole where the needle fits in. Holding it tightly in your left hand with the scarf facing right, insert your needle into this opening and push it all the way up. With your right hand, grab one of your small screwdrivers and screw the small screw to the right of the needle tightly until the needle is in place. TIP: Place a piece of paper or fabric over the throat plate to avoid dropping a loose needle into the machine (it's a pain in the behind!!).
3. Pull the thread behind the last small metal thread guide. From left to right, thread the end of your thread through the eye (hole) of the needle. Pull the end of the thread to the back.

Bringing up the bobbin thread is the final step in threading your machine before sewing. You will be using your hand wheel for this part of the process.

1. Keep the bobbin cover plate open. With your left hand, pull the top thread gently to the left/back and hold it in place.
2. Turn the hand wheel slowly towards you until the thread from the bobbin jumps up from the bottom of the machine. You should see it looped around the top thread in between your needle and the feed dogs.
3. Use one of your screw drivers to pull the loop out, leaving you with a bobbin thread that is ready to go!
4. Pull the threads to the back and close the throat plate.

Before sewing, you have to install your foot. The thread passes through and under the foot to keep it in place, and the foot holds your fabric in place while sewing.

1. Locate the larger screw behind the needle.
2. Bring your foot into the groove to the right of the large screw - it should fit right into place. Holding the foot in its groove, use one of your screwdrivers to screw it in tightly until it is locked into place.
3. Lift the foot using your knee bar (push to the right using knew), and pull both the top and bottom thread through the slit in the middle of the foot and bring it to the back.

Congrats! You threaded your machine! Before sewing into your final fabric, grab a scrap piece and sew a sample. Use your knee bar to raise your foot and place your fabric on the machine. (Sew through two layers rather than just one.) Line it up with the desired seam allowance guide on the throat plate and lower the foot. Sink your needIe into the fabric by slowly turning the hand wheel towards you. Turn on the machine and sew a straight line.

Tip: I used a different color for the top thread and the bobbin thread in this example so that I could easily differentiate between the two after sewing a sample. This can be helpful if you have a tension issue or other issue - it can help you figure out where the problem is coming from. For most projects, however, you will want to use the same color for both.