The Lacis shuttle winder works with a 4.25″ Tatsy shuttle. You use it to wind thread on to your shuttle. And it helps to preserve the integrity of your thread. Let me explain.
Did you ever notice how a shoelace frays when it has been pulled through eyelets too many times? On a smaller scale, the same thing can happen with tatting thread. When you wind thread on to your shuttle, you force the thread between two blades. When the blades pinch the thread, there is a clicking sound. This disturbs or weakens the natural twist of the thread. In the following example, let’s call the weakened or pinched point, Section A. If your thread has aged, then the point at which it is more likely to break is Section A. Or if you use Section A for a join and because the thread twist has been disturbed, the crochet hook can easily split the thread, making your tatting less tidy.
The pinch is more apparent on larger sizes of thread such as size 10, 5, or larger. A thread winder helps you avoid these things. The winder is seated between the blades and functions like the contour of a bow pulling the blades apart. It leaves a thin space for the thread to pass through without touching the blades. No damage is done to your thread.