Coil and Rotary Machines! What are they Really? — Carson Hill
Coil and Rotary Machines! What are they Really?
[05:22] “[Rotaries] are spinning, and [coils] are oscillating. The spinning motion of a rotary needs to be translated into oscillating motion. And that’s one of the main challenges, because ultimately we want oscillation which is what coils do by default.”
— Carson Hill
Coil Machines are basically an open circuit. They have two bobbins wrapped in copper wire turning them into coils. When you add electricity from the clip cord it sends a current through the machine and turns the 2 coils into an electromagnet pulling the armature bar down towards the coils. Then the current is released and the armature bar returns. This happens over and over in rapid succession.
A Rotary Machine on the other hand can vary drastically from one manufacturer to another. But, the main driver of the system is a rotating motor with a single coil inside. The motor is attached to a drive shaft which spins a cam wheel. In order for the motor to function properly the cam must make one full rotation. This last point is very important because it’s one of the defining factors that makes one machine more efficient than the other.
Depending on whether you have an “L” shaped rotary or a “Pen” style rotary is where the differences in cam systems and mechanisms start to occur.
- L Shape - The motor is positioned sideways and the needle bar is attached directly to the spinning cam, this creates the up and down motion for the bar.
- Pen Style - The motor is positioned vertical, and the cam will have some type of pin, grooved plate, or magnet that pushes a plunger bar into the plunger of a needle cartridge to extend the needles.
As I said before rotary machines vary widely between manufacturers so it may be good to look into how your machine works.
