Challenge

Drafting of various geometries using Chamfer, Fillet tool in AutoCad

VVineetha Enukula18 Jul 2022

Q. Drafting of various geometries using Chamfer, Fillet tool in AutoCad

AIM:- To draft given sketches in autocad using various tools.

INTRODUCTION:-

Autocad offers various tools to perform different tasks. The various tools which are used for drafting in this project are briefly described.

COMMANDS USED:

Line
Circle
Chamfer
Fillet
Offset
Rotate
Object Snap
Trim
Extend
Lengthen
Mirror
Join
Arc
Points
Construction Line

LINE:

Line is a handy key in autocad which is used frequently. It creates a series of contiguous line segments. Each segment is a line object that can be edited seperately.
Type command "l" in command box and then click on enter to get a line. To specify first point-Sets the starting point for the line and click a point location with object snaps or grid snaps turn on, then place the point precisely. We can also enter the coordinates based on the requirement.
That is how a new line starts. To specify the endpoint of line segment. We can also use polar and object snap tracking together with direct distance entry or from any one the coordinate methods.
If we use line to create a polygon then there is a command "C" enter (Close) used to connect the first and last segments.
If not there is a command which is displayed on cammond box while working with line tool that is undo whic is used to remove the most recent segment of a line sequence.

CIRCLE:

To create a circle type the command "c".
Specify the centre point to create a circle based on the requirement centre point is defined either by radius or diameter. That is enter the value to specify a point that is coordinate (x,y) and then the value, or specify the next point.
There are different ways to create a circle.
1. 3P (Three points)
2. Tan, Tan, Tan
3. 2P (Two points)
4. TTR (Tangent, Tangent, Radius).

CHAMFER:

To create a chamfer type the command "cha".
An angled line that meets the endpoints of two straight 2D objects.
It is sloped transition between two surface. In order to get the surface as chamfered the specify the horizontal and veritical distance or specify the distance and angle.
Select the objects in such way that the requirement is reached.

FILLET:

To create a fillet type the command "f".
The fillet tool helps form round corners between any two entities that form a sharp vertex. A round or fillet can be created between two objects of the same or different object types: 2D polylines, arcs, circles, ellipses, elliptical arcs, lines.
If the two selected objects are on the same layer, the arc defined is created on that layer. Otherwise, the arc is created on the current layer. The layer affects object properties including colour and line type.

OFFSET:

To create a offset type the command "o".
Specify the offset distance through which it is required. Select the object to offset.
The offset command in AutoCAD is used to create parallel lines, concentric circles, and parallel curves.
The offset objects can also be modified further according to the requirements. Here, modification of offset object means that we can apply trim, extend, and other methods on it.

ROTATE:

To rotate an object type the command "ro".
Select the objects you wish to rotate and press Enter to accept the selection.
Specify the base point around which you want to rotate them.
Type an angle to rotate the objects by or use the cursor to indicate an angle.

OBJECT SNAP:

Object snaps provide a way to specify precise locations on objects whenever you are prompted for a point within a command.
The command used is "os" - object snap or F3 function key.
We can use object snaps to create a line from the centre of a circle to the midpoint of another line. The available options are endpoint (end), midpoint (mid), centre (cen), geometric centre (cen), nearest (nea), quadrant of a circle (quad), intersection, perpendicular, tangent, parallel, extension, apparent intersection, nodes, insertion points etc.

TRIM:

To trim a object the command used is "tr"
In general trim is used to trim edges and that is possible only if there is intersection.
There are two modes that is quick mode and standard mode.
Quick Mode:- To trim objects, select the objects to be trimmed individually, press and drag to start a freehand selection path, or pick two empty locations to specify a crossing Fence. All objects automatically act as cutting edges. Selected objects that can't be trimmed are deleted instead.
Standard Mode:- To trim objects, first select the boundaries and press Enter. Then select the objects to be trimmed. To use all objects as boundaries, press Enter at the first Select Objects prompt.

EXTEND:

To extend the object the command used is"ex".
Extends objects to meet the edges of other objects.
To extend objects, first select the boundaries. Then press Enter and select the objects that you want to extend. To use all objects as boundaries, press Enter at the first Select Objects prompt.

LENGTHEN:

To lengthen the object the command used is "lengthen".
Changes the length of objects and the included angle of arcs.
We can specify changes as a percentage, an increment, or as a final length or angle. LENGTHEN is an alternative to using TRIM or EXTEND.

MIRROR:

To mirror the object the command used is "mi".
Create a mirrored copy of selected objects.
We can create objects that represent half of a drawing, select them, and mirror them across a specified line to create the other half.

JOIN:

To join the object the command used is "j".
Joins the endpoints of linear and curved objects to create a single object.
Combines a series of finite linear and open curved objects at their common endpoints to create a single 2D or 3D object. T
he type of object that results depends on the types of objects selected, the type of object selected first, and whether the objects are coplanar.

ARC:

To create arc of an object the command used is "a or arc ".
To create an arc, you can specify combinations of centre, endpoint, start point, radius, angle, chord length, and direction values.
Arcs are drawn in a counter clockwise direction by default. Hold down the Ctrl key as you drag to draw in a clockwise direction.

POINTS:

To create point of an object the command used is "ptype or dpptype".
Creates a point object. Point’s objects can act as nodes to which you can snap objects.
We can specify 2D and 3D locations for a point.
The current elevation is assumed if you omit the Z coordinate value.
The PDMODE and PDSIZE system variables control the appearance of point objects.

CONSTRUCTION LINES:

To create construction line of an object the command used is "xl".
Construction lines (also known as xlines) are temporary linework entities that can be used as references when creating and positioning other objects or linework.
Construction lines are either circles or straight lines that extend to infinity in both directions.

Q1.

AIM:- To draft the following using decimal system of units.

PROCEDURE:-

Create a new sheet.
Change units to decimal, click on the precision to 0.00 and the dimension to meter and then ok.
Change the limits from (0,0) to (420,120).
Zoom-All
Select the line and draw the length, specify the first point as (0,0) and followed by (@3<0) to get the base line.
Specify the next point as (@2.12<45), (2.83<135), (@2<180) and close it using closing command.
To sketch the circle, select the circle command and then draw the circle by specifying the coordinate as (1.5,0) and specify the diameter as 1.20 units.
Similarly, draw another circle with the coordinate as (1.50,2.50) and followed by diameter 0.80 units.
Annotate and give dimension to the line segments and circles.
Change the Dimension style based the requirement.
Use the command as mtext to create the text.

RESULTS:-