A drawing tool for drawing circles. There are two feet, the upper end is hinged, and the lower end can be separated or closed at will to adjust the radius of the drawn arc. The end of one foot is a needle tip, and the end of the other foot can be fitted with a foot for drawing pencil lines or ink lines. Some compasses are equipped with telescopic rods to draw larger circles. There are beam compasses, spring compasses and movable core compasses.
Second, the structure of compasses
Compass consists of a nib, a rotating shaft, compass legs, a ruler, a hinge, a pen body, a nib, a compass tip and small ears, and a plunger at the lower end of the nib is at the upper end of the pen body. The lower end of the pen body is screwed on the upper end of the pen tip, the flush end of the small ear is welded in the middle of the outer side of the compass leg, and the lower end of the compass leg is clamped on the upper end of the compass tip.
It is characterized in that one side of the pen body is attached to one side of the folding leaf, and the other side of the folding leaf is attached to the middle of one end of the ruler; Inserts on both sides of the upper end of the seam of the pen body are located at both ends of the rotating shaft, and the shaft body of the rotating shaft is connected to the upper end of the compass leg through a sleeve.
Third, how to assemble compasses
Main part (required)
Extension rod (metal drawing compass configuration)
Charcoal box (required)
Charcoal feet (required)
Stitch (there is an attachment on the main body, usually there is an attachment)
Duck-billed pen (a purely manual drawing tool, which is found on pure metal compasses, but generally not on plastic compasses)
Extra pen cover (plastic compasses will be provided instead of "duckbill pen")
Installation:
The main part is similar to a bracket, and the other parts are mounted on it, with two feet. One of the feet is a "fulcrum foot", and a pin is usually installed to determine the center of the circle; The other foot is the "moving part", which contains the moving part in the process of drawing. Extension rod, charcoal pen foot, duckbill pen and additional pen cover can be installed (even pins can be installed).
Telescopic rods are used to extend the span of the two legs of the main body and are generally installed in the "movable part".
When charcoal feet are used for painting, they are obviously used on paper. Can only be installed in the "moving part".
The charcoal box is full of spare charcoal scraps. Don't make it too sharp. )
Pins can be installed on both feet. Installed on the "fulcrum foot", it is used to fix the center of the circle and support the compass to do circular motion. Installed on the "moving parts" are "double pins", which are generally used to measure the distance between two points.
The duckbill pen is installed on the "movable part", and the pen tip can be stained with ink, which can be directly displayed on the template when it is used for pure manual drawing. On the template, there are some charcoal pens that can't be drawn. )。 Besides, duckbill pens have many other uses, but for students, they are basically useless.
The additional pen cover is installed on the "movable part", which is only available in plastic compasses. It is an additional accessory specially prepared for students. The compass was not originally designed with this accessory. The function of this accessory is to hold a pen (any pen) and fix it on the compass.