Threading the Brother LX3817: The Basic Path

The Brother LX3817 threads from the top down, starting at the spool pin and moving through a series of guides, tension discs, and the needle. The machine has a presser foot lever on the back — you must raise it before threading, because raising it opens the tension discs and lets thread pass through. If you skip this step, the thread will not seat properly and your stitches will be loose or skip.

The threading path is marked on the machine itself with small numbers and arrows. Following them in order takes the guesswork out of the process. Most threading problems — loose stitches, thread breakage, skipped stitches — trace back to a thread that missed one of these guides or did not seat in the tension discs.

Key Takeaways

  • Raise the presser foot lever before you start threading so the tension discs open and accept the thread.
  • Follow the numbered guides on the machine from the spool pin down through the tension assembly, then to the needle.
  • The thread must sit fully in the tension discs — if it is only resting on top, it will not tension correctly.
  • After threading, lower the presser foot to close the tension discs and hold the thread in place.
  • If stitches skip or break after threading, rethread completely rather than trying to adjust tension first.

Step-by-Step Threading Instructions

Start with the presser foot lever in the up position. Place your spool of thread on the spool pin at the top left of the machine, with the spool sitting flat against the pin. If the spool is loose or tilted, it will not unwind smoothly.

Pull the thread up and to the right, then down into the first guide — a small metal hook or loop marked with the number 1. Continue following the numbered path: thread 2 is usually a larger guide on the right side of the tension assembly. From there, the thread enters the tension discs, which look like two flat metal plates stacked together. This is the critical step: the thread must slide all the way down between these discs so it sits in the groove at the bottom. If the thread only rests on top of the discs, tension will not work.

After the tension discs, thread through guide 3 (often a small loop above the needle area), then through the needle eye from front to back. The needle should be at its highest position when you thread it. If the needle is lower, raise it by turning the handwheel toward you until the needle bar reaches the top.

Once the thread is through the needle, lower the presser foot lever. This closes the tension discs and locks the thread in place. You are now ready to sew.

What to Do If the Thread Will Not Seat in the Tension Discs

The tension discs are two metal plates that grip the thread to control how much slack it has while you sew. If the thread sits on top of the discs instead of sliding between them, the machine cannot tension it properly. The easiest way to check is to look at the discs from the side — you should not see thread resting on the top surface.

If the thread is not seating, pull it out completely and start over. Make sure the presser foot is still raised — if you have lowered it, raise it again to open the discs. Pull the thread down firmly as you guide it between the discs. You may feel slight resistance as it enters; that is normal. Once it is seated, you should not be able to pull the thread out easily by hand.

Threading the Needle Correctly

The needle on the Brother LX3817 has a flat side and a rounded side. The flat side faces toward the back of the machine. When you insert a new needle, make sure the flat side is oriented correctly — if it is backwards, the thread will not catch in the groove and stitches will skip.

To thread the needle itself, bring the thread to the needle eye and push it through from front to back. Some people find it easier to use a needle threader, which is a small wire tool that comes with the machine. Insert the wire loop through the needle eye, place the thread through the wire loop, then pull the wire back out — it will pull the thread through the needle eye with it.

After threading the needle, leave a tail of thread hanging down at least 4 to 6 inches. When you start sewing, hold both the top thread and the bobbin thread with your fingers for the first few stitches. This prevents the needle from pulling the thread out of the needle eye as it begins to move.

Bobbin Threading and Setup

The bobbin is the small spool of thread that sits underneath the needle plate. The Brother LX3817 uses a drop-in bobbin system, meaning the bobbin sits in a case that drops into the machine from the top. To load the bobbin, raise the presser foot, remove the needle plate (a small metal plate under the needle), and drop the bobbin case into the opening.

Before you insert the bobbin, wind thread onto an empty bobbin using the bobbin winder on the side of the machine. Place an empty bobbin on the winder pin, guide the thread through the tension guide on the winder, and press the bobbin against the winder wheel. The wheel will spin and wind the thread onto the bobbin automatically. When the bobbin is full, it will stop automatically.

Once the bobbin is wound, insert it into the bobbin case so the thread unwinds counterclockwise. The thread should sit in the tension spring on the case. Pull the thread through the slot in the case, then insert the entire case into the machine. The top thread and bobbin thread should be ready to sew once both are threaded.

Common Threading Mistakes and How to Fix Them

The most common mistake is forgetting to raise the presser foot before threading. If you thread with the presser foot down, the tension discs stay closed and the thread cannot pass through them. The result is that the thread appears to be threaded, but it is actually resting on top of the discs. Stitches will be loose and uneven. The fix is straightforward: raise the presser foot, rethread, and lower it again.

Another frequent problem is threading the needle from back to front instead of front to back. The needle has a groove on one side that the thread must follow. If the thread enters from the wrong direction, it will not sit in the groove and will slip out as you sew. Always thread from the front of the needle toward the back.

Skipped stitches often mean the thread missed one of the guides or did not seat fully in the tension discs. Rather than adjusting the tension dial, rethread the entire machine. Tension adjustment should be your last resort, not your first. Most threading problems are solved by rethreading.

Checking Your Threading Before You Sew

Before you start a project, do a quick visual check. Look at the path the thread takes from the spool to the needle — it should follow the numbered guides without any loops or slack. The thread in the tension discs should be invisible from the top; you should only see it entering and exiting the assembly. The needle should have thread running through it from front to back.

A good test is to hold the presser foot up and gently pull the top thread. It should have some resistance — the tension discs are holding it. If it pulls out easily, the thread is not seated in the discs and you need to rethread. Once you lower the presser foot, the resistance should increase slightly because the discs are now fully closed.

Frequently Asked Questions

Why do my stitches skip after I thread the machine?

Skipped stitches usually mean the thread is not seated in the tension discs or the needle is threaded from back to front instead of front to back. Rethread the entire machine, making sure the thread slides all the way down between the tension discs and enters the needle from the front. If skipping continues, the needle may be bent or inserted backwards — remove it and check that the flat side faces the back of the machine.

Can I thread the machine with the presser foot down?

No. The presser foot must be raised to open the tension discs so the thread can pass through. If you thread with the foot down, the thread will rest on top of the discs instead of sitting between them, and tension will not work. Always raise the presser foot before threading and lower it after the thread is in place.

What if the thread keeps breaking while I sew?

Thread breakage usually points to tension that is too tight, a bent needle, or thread that did not seat in the tension discs. Start by rethreading the machine completely. If breakage continues, check that the needle is straight and inserted correctly with the flat side facing back. If the needle is fine, try loosening the tension dial slightly — turn it to a lower number and test on scrap fabric.

Do I need to rethread if I change thread color?

You do not have to completely rethread, but it is a good idea. Old thread can leave lint in the guides and tension discs. If you want to skip rethreading, at least pull the old thread out, raise the presser foot to open the tension discs, and run the new thread through the same path. This clears out any lint and ensures the new thread seats properly.

How do I know if my needle is threaded correctly?

The thread should run through the needle eye from front to back, and you should see it clearly when you look at the needle from the side. If you cannot see thread in the needle eye, it is not threaded. A straightforward test is to gently tug the thread — if it pulls out of the needle easily, it was not fully inserted. Rethread and push the thread all the way through so it exits the back of the needle.