Automatic Thread Delivery — must-have feature for those looking to purchase a new serger
July 12, 2023/Comments Off on Automatic Thread Delivery — must-have feature for those looking to purchase a new serger
Automatic Thread Delivery:
The Most Underrated Technology in Sewing
Did you know that the best sergers in the world do not use a traditional tension system? Instead, they use a technology called Automatic Thread Delivery (ATD), which completely eliminates the use of tension altogether. Half of our staff is comprised of avid sewists and garment-makers, all of whom own sergers equipped with ATD. The other half of our staff consists of sewing machine technicians, who exhale a sigh of relief when the serger they are tuning up is equipped with ATD instead of the traditional tension system. Since we find that not a lot of people are aware of ATD or how it works, the goal of this email is to shed light on the most underrated technology in sewing: Automatic Thread Delivery.
Before talking about how ATD works, it is important to first understand the basics of traditional tension systems.
Traditional home sewing machines tie knots with 2 threads– the top thread and the bobbin thread. Sergers generally use 3 to 5 threads to tie a knot that is more complicated than that of a home sewing machine. Pictured below is an image of a home sewing machine’s tension assembly. Traditional sergers also use a similar tension assembly. As you can see, the pictured tension assembly contains two metal discs.
When you thread the top half of the machine (with the presser foot in the raised position, of course), those discs separate and the thread slides between the discs. When you are ready to sew, you lower the presser foot onto the fabric and discs close together around the thread. As the machine sews, the thread is constantly pulled through the closed discs. The closed discs apply constant tension on the thread, a necessary requirement for a machine if it is to make a good stitch.
Think about tying your shoes. As you complete the various steps required to a tie a knot, your fingers keep constant pressure on the shoelaces, in order to keep the laces taut. Juxtapose this with children, who don’t have the strength to keep the laces taut as they complete the shoe-tying steps. Even though they technically tie a knot, the knot will not be tight, and their shoes will inevitably come untied. The same principle applies to sewing machines– to successfully make a stitch, the machine must keep the thread taught. How does your machine do this? Through the machine’s tension assembly.
As many already know, you are able to adjust your tension. On a home sewing machine with two threads, you might adjust the tension depending on where the knot is sitting in the fabric. In a perfect world, the knot sits right in the middle of the fabric. However, the knot might start poking up on either the bottom or topside of the fabric. If the knot is coming up to the top, then we loosen the top tension. If it is poking down through the bottom, then we tighten the top tension. That is the general rule.
What about sergers? Although traditional sergers use a similar tension system as home sewing machines, adjusting the tension is not as simple. Because sergers use 3-5 threads instead of 2, the knot they stitch is more complicated. If the tension is unbalanced, balancing it is not as simple as readjusting for the knot poking out of the fabric.
When tension is off on a serger, the stitch looks ugly and it is not clear why. Often you will be using 4 threads, which means 4 sets of tension discs. If your stitch is off, which tension disc do you adjust? The left needle or the right needle? The upper looper or the lower looper? Do you need to tighten it or loosen it?
Serger tension is notoriously difficult to balance. The tiniest external factors can throw it off, such as switching to a different colored thread that is more heavily dyed. For example, tension will naturally increase when you switch from white thread to black thread. Until the invention Automatic Thread Delivery, balancing serging tension would require tinkering with the different tension dials. This could easily result in at least 30 minutes of troubleshooting. Your tension is off? Adjust 1 or 2 of the tension dials and sew. Did that not work? Adjust the other 2 and try again. Does it look worse than it did before? With a traditional serger tension system, you will have to accept that achieving perfect tension will require lots of trial and error.
Automatic Thread Delivery
Baby Lock’s Automatic Thread Delivery puts an end to all that tinkering and trial and error. Rather than putting tension on the thread itself, ATD delivers the required length of thread to form a balanced stitch. This is achieved by an internal mechanism of the machine– sliding metal plates that determine the length of the thread delivered into the stitch. Machines with ATD work in a manner that is binary– thread is either being delivered, or it is not being delivered. There is no tension. Therefore there is no tension adjustment– no tinkering, no repeated trial and error. And, on top of all that, ADT is a purely mechanical feature (as seen in the picture below). No computers are involved whatsoever.
Automatic Thread Delivery System lays the thread on the fabric as each stitch is formed. The fabric is not responsible for pulling the threads through the tension discs as on other overlockers. That means there is no stress placed on the fabric, allowing it to flow under the foot without being stretched or damaged. This allows you to sew from delicate tissue or silk chiffon through to lycra and layers of denim or fleecy without having to make any adjustments to the machine settings. Furthermore, the machine does not care what kind of thread you use– you can switch from white thread to black thread seamlessly, as well as switching between something like Maxilock to Surelock. Because there is no tension, the machine does not “feel” the thread like other sergers. No matter what you use, a perfect stitch is delivered every time. You will never have to tinker with tension ever again.
History tends to repeat itself, and I have noticed a pattern when it comes to the history of Baby Lock sergers. Time and time again, Baby Lock is at the forefront of innovation, and the rest of the sewing machine industry is forced to play catch-up. This happened at the genesis of the company, when Baby Lock created the first “baby” overlock machine for home use. It happened again when they invented air-jet threading. It has now happened yet again, with the invention of automatic thread delivery. It is important to note that Baby Lock still has a patent on automatic thread delivery, so until the patent runs out, Baby Lock will be the only manufacturer who offers this game-changing feature.
Surprisingly, a technology as revolutionary as ATD is not hellaciously expensive. You can own a new machine equipped with ATD for as low as $1,799 with the Baby Lock Victory.
Automatic Thread Delivery can also be found on coverstitch and serger combination machines. For example, theBaby Lock Accolade and Baby Lock Triumph can both serge and coverstitch, and come equipped with ATD.
The following statement is not intended to be hyperbolic.
After 30+ years of experience in the sewing machine business, it is safe to say that Baby Lock sergers equipped with ATD have the highest satisfaction rate out of any other product we carry. People absolutely love them. They are just that good.