**Flyer leading and bobbin leading principle in roving:**

Table of Contents

## 1. Flyer leading principle in roving:

Flyer leading is the process of winding the roving bobbin through a spindle or flyer while keeping the speed of the bobbin constant. But the condition here is that as the roving is added to the bobbin, the diameter of the bobbin increases, thus the surface area of the bobbin also increases. Therefore, to keep the winding fixed, as the diameter of the bobbin increases, the speed of the spindle or flyer is gradually increased to keep the amount of winding constant. https://bdfabric.com/how-does-winding-occur-in-roving-frame/

Two things are at work here

(1) Speed of bobbin.

(2) Speed of spindle or flyer.

To explain the winding principle, the diameter of the bobbin increases with the winding of the bobbin. As the diameter of the bobbin increases, so does the surface area of the bobbin. As a result, the winding capacity of the bobbin increases beyond the amount of roving delivered from the front roller. In this condition, the roving may tear and the winding may stop. So in order to get rid of this condition, as the diameter of the bobbin increases, the speed of the flyer also increases. As a result, the gap between the surface speed of the bobbin and the surface speed of the spindle is always constant, that is, the speed of the flyer increases gradually to keep the surface speed of the empty bobbin the same as the speed gap of the flyer.

**Flyer leading and bobbin leading principle in roving**. But it is not possible to increase the speed of the flyer when the surface area of the bobbin is too high. A flyer has a speed limit. Also in the beginning when the bobbin is empty the speed of the flyer is also kept very low. Therefore, the starting flyer speed must be kept lower than the maximum specified flyer speed so that the flyer speed can be increased as the bobbin diameter increases.

## 2. Bobbin leading principle in roving:

The surface speed of the bobbin is kept constant by gradually reducing the speed of the bobbin while keeping the speed of the spindle or flyer constant. The process or principle of roving winding is called bobbin leading. Here, as the diameter of the bobbin increases, the speed of the bobbin is reduced, and the two parts, the bobbin, and the flyer rotate very fast during the machine to wrap the roving in the delivery part of the roving frame so that the roving slowly wraps around the bobbin.

Both the flyer and the roving spin very fast and there is some difference in speed between the two, causing the roving to get tangled in the bobbin. If the speed of the bobbin and the flyer were the same, then the roving would never get tangled in the bobbin. There is a slight difference in the speed of the bobbin and the flyer, this difference is the winding speed. As much roving as the machine’s front roller delivers, the roving wraps around the bobbin surface. This mixing rate is always constant.

## Mechanism of winding principle:

As the diameter of the bobbin increases in the simplex machine, the speed of the bobbin is reduced to keep the amount of winding fixed and as the diameter of the bobbin increases, the speed of the builder is also reduced. Spindles or flyers and bobbins get motion from the main driving shaft. So there is a system, however, in terms of which the speed of the bobbin decreases as the diameter increases. An intermediate variable speed along the diameter of the bobbin solves the above task. A pair of angle drums are used to increase and decrease the speed of the bobbin. The movement of angle drum belt moves from right to left or left to right (according to the design of the angle drum) and slows down the speed of the bobbin.

## Objects of differential motion:

The objects of differential motion are given below-

1. As the bobbin’s diameter increases, the bobbin’s speed decreases.

2. As the diameter of the bobbin increases, the speed of the builder decreases.

3. Keep the winding on speed constant by keeping the speed difference between the bobbin and flyer equal.

4. Through differential motion, the roving can be wound on the bobbin without additional tension or slack.