The designer is often faced with the need to build an arc of a given curvature. Parts of buildings, bridge spans, fragments of parts in mechanical engineering can have such a shape. The principle of constructing an arch in any type of design is no different from what a student has to do in a drawing or geometry lesson.
Necessary
- - paper;
- - ruler;
- - protractor
- - compasses;
- - computer with AutoCAD program.
Instructions
Step 1
To draw an arc using ordinary drawing tools, you need to know 2 parameters: the radius of the circle and the angle of the sector. They are either specified in the conditions of the problem, or they must be calculated based on other data.
Step 2
Place a dot on the sheet. Mark it as O. From this point, draw a line and mark the length of the radius on it.
Step 3
Align the zero division of the protractor with point O and set aside the given angle. Through this new point, draw a straight line starting at point O and plot the length of the radius on it.
Step 4
Spread the legs of the compass to the size of the radius. Put the needle at point O. Connect the ends of the radii with an arc with a compass pencil.
Step 5
AutoCAD allows you to draw an arc using several parameters. Open the program. In the top menu find the main tab, and in it - the panel "Draw". The program will offer several types of lines. Select the "Arc" option. You can also act through the command line. Enter the command _arc there and press enter.
Step 6
You will see a list of parameters by which you can build an arc. There are quite a few options: three points, center, beginning and end. You can draw an arc from a start point, center, chord length, or interior corner. A variant is offered by two extreme points and a radius, by a central and an end or starting points and an inner corner, etc. Choose the appropriate option based on what you know.
Step 7
Whatever you choose, the program will prompt you to enter the parameters you want. If you are drawing an arc from any three points, you can specify their location using the cursor. You can also specify the coordinates of each point.
Step 8
If you have an angle among the parameters by which you draw an arc, the context menu will have to be called a second time. First, mark the points specified in the conditions with the cursor or using coordinates, then call the menu and enter the angle size.
Step 9
The algorithm for constructing an arc based on two points and the length of a chord is exactly the same as for two points and an angle. True, in this case it should be borne in mind that the chord contracts 2 arcs of one circle. If you are drawing a smaller arc, enter a positive value, a larger one negative.
