There are not so many people in our time who have never in their life had to draw or draw something on paper. The ability to perform the simplest drawing of any structure is sometimes very useful. You can spend a lot of time explaining "on the fingers" how this or that thing was done, while one glance at its drawing is enough to understand it without any words.
It is necessary
- - Whatman sheet;
- - drawing accessories;
- - drawing board.
Instructions
Step 1
Select the sheet format on which the drawing will be executed - in accordance with GOST 9327-60. The format should be such that the main views of the part in the appropriate scale, as well as all the necessary cuts and sections, can be placed on the sheet. For simple parts, choose the A4 (210x297 mm) or A3 (297x420 mm) format. The first can be located with its long side only vertically, the second - vertically and horizontally.
Step 2
Draw a drawing frame, departing from the left edge of the sheet 20 mm, from the other three - 5 mm. Draw the title block - a table in which all the data about the part and the drawing are entered. Its dimensions are determined by GOST 2.108-68. The width of the title block is unchanged - 185 mm, the height varies from 15 to 55 mm, depending on the purpose of the drawing and the type of institution for which it is performed.
Step 3
Select the scale of the main image. Possible scales are determined by GOST 2.302-68. They should be chosen such that all the main elements of the part are clearly visible on the drawing. If, at the same time, some places are not clearly visible, they can be taken out in a separate view, showing them with the necessary magnification.
Step 4
Select the main image of the part. It should represent such a direction of looking at the part (projection direction) from which its design is revealed most fully. In most cases, the main image is the position in which the part is on the machine during the main operation. Parts that have an axis of rotation are usually positioned in the main image so that the axis is horizontal. The main image is located at the top of the drawing on the left (if there are three projections) or close to the center (if there is no side projection).
Step 5
Determine the location of the remaining images (side view, top view, sections, cuts). The views of a part are formed by projecting it onto three or two mutually perpendicular planes (Monge's method). In this case, the part should be located in such a way that most or all of its elements are projected without distortion. If any of these types is informationally redundant, do not do it. The drawing should have only those images that are needed.
Step 6
Select the cuts and sections you want to make. Their difference from each other is that the section also shows what is behind the cutting plane, while the section displays only what is located in the plane itself. The cutting plane can be stepped and broken.
Step 7
Start drawing directly. When drawing lines, be guided by GOST 2.303-68, which defines the types of lines and their parameters. Place images at such a distance from each other that there is enough space for sizing. If the planes of the sections pass along the monolith of the part, hatch the sections with lines running at an angle of 45 °. If at the same time the hatching lines coincide with the main lines of the image, you can draw them at an angle of 30 ° or 60 °.
Step 8
Draw dimension lines and add dimensions. In doing so, be guided by the following rules. The distance from the first dimension line to the image outline must be at least 10 mm, the distance between adjacent dimension lines must be at least 7 mm. The arrows should be about 5 mm long. Write the numbers in accordance with GOST 2.304-68, take their height equal to 3.5-5 mm. Place the numbers closer to the middle of the dimension line (but not on the image axis) with some offset relative to the numbers on the adjacent dimension lines.
