Technical drawing. Drawing
How are ideas for new models born? It's different for everyone. Some are inspired by their favorite films, others by glossy magazines, others by the colors of nature. But no matter what inspires fashion designers, all their ideas that are born in the creative process find their expression in artistic sketches of new models.
This is natural, because in order to begin the process of pattern modeling, you need to think through each new model down to the smallest detail - silhouette, constructive solution, color and texture of fabric, finishing - everything affects how the finished product will look. At the stage of creating an artistic sketch, you can make any changes to the product, experiment with color, length, show your imagination, give freedom to creativity, imagination and create a real masterpiece!
Advice! Keep a separate album for your artistic sketches and sketch all new ideas in it.
Keep a separate album for your artistic sketches and sketch all new ideas in it. Even if some of them do not find immediate implementation, none of the sketches should be thrown away, because they may be useful to you in the future. When adding new models to the album, sometimes return to previous, unrealized ideas. Perhaps, after some time, you will look at them in a new way and bring them to life.
And now a few words about what an artistic sketch should be.
What is an artistic sketch of a model?
You can first do a rough sketch or rough sketch to get your idea down on paper. It may be unclear, disproportionate, and lacking precise drawings. These are the germs of an idea initial stage, when you can depict a flight of fancy as you consider necessary, understandable only to you. Experiment at this stage without limiting yourself in anything.
Rice. 1. Fore-sketch of a dress
This is followed by the creation of an artistic sketch of the model.
An artistic sketch of a model is a drawing made using any drawing technique. You can use gouache, watercolor, colored or single-color pencils, felt-tip pens and whatever is at hand for drawing. An artistic sketch is performed on a figure in an arbitrary pose. The main thing is that the model you draw conveys the mood, matches the image that you have in mind, is aesthetically pleasing and comfortable to wear. All this needs to be thought through at the stage of creating an artistic sketch.
Rice. 2. Artistic sketch of the model - watercolor, ink
Rice. 3. Artistic sketch of the model - graphics
After completing the artistic sketch, it must be converted into a technical sketch, according to which it will be necessary to model the patterns.
Technical sketch of the model
A technical sketch of a model is a drawing of a product on a conventionally typical figure, with a clear definition of all the design features of the model, using a grid of base lines - the base of the neck, chest, waist, hips, central axis. This will allow you to more accurately calculate the location of structural seams, parts, pockets, etc.
Rice. 4. Technical sketch of the model - front and back
Make yourself a rule: always accompany the technical sketch of the model detailed description and calculation of the required amount of fabrics and applied materials for its sewing. This will greatly simplify your work and allow you to more accurately estimate the cost of the finished product, make it possible to optimize the modeling and cutting process and get more exact result. But this is exactly what we strive for!
In the description of the technical drawing of the product, be sure to indicate the following parameters:
1. Brief description free form products.
2. Silhouette, product design features, size.
3. Calculation and description of the required amount of fabric for the product.
4. Description and calculation of the required quantity additional materials for the product (gaskets, fittings, threads, etc.).
5. Features of the model.
Rice. 5. Description of the technical drawing
If artistic sketches, as mentioned above, are best sketched on landscape paper, a squared notebook is ideal for technical drawing. In it you can easily enter a technical sketch and fill out a table describing the model.
Once you have done all the preparatory work and created technical drawing, it will be much easier for you to create a basic pattern for the product and develop patterns.
Ready-made templates for your sketches
Rice. Art sketch template
And now - the fun part! We have prepared a template with silhouettes for you female figures for artistic sketches on A4 format. Just download the pdf file, print it on a black and white printer and draw your sketches directly from the silhouettes.
This way you won’t have to waste time drawing the figures - after all, we’ve already drawn them for you! By the way, it is very convenient to store finished sketches in a folder.
Unlimited creativity to you!
Technical drawing
To quickly and most clearly convey the shape of an object, model or part, technical drawings are used.
Technical drawing - this is an image made by hand according to the rules of axonometry, observing proportions by eye, i.e. without the use of drawing tools. This is how a technical drawing differs from an axonometric projection. In this case, they adhere to the same rules as when constructing axonometric projections: the axes are placed at the same angles, the dimensions are laid along the axes or parallel to them, etc.
Technical drawings give a visual representation of the shape of a model or part; it is also possible to show not only appearance, but also their internal structure by cutting out part of the part in the directions of the coordinate planes.
Rice. 1. Technical drawings.
The most important requirement The requirement for a technical drawing is clarity.
Execution of technical drawings of parts
When performing technical drawings, the axes must be placed at the same angles as for axonometric projections, and the dimensions of objects must be laid out along the axes.
It is convenient to perform technical drawings on lined paper.
In order to quickly and correctly complete a technical drawing, you need to gain the skills to draw parallel lines at different angles, at different distances, of different thicknesses without the use of drawing tools, without using devices, to build the most used angles (7°, 15°, 30°, 41° , 45°, 60°, 90°), etc. It is necessary to have an idea of the image of various figures in each of the projection planes, to be able to draw images of the most used ones on a technical drawing flat figures and simple geometric shapes.
In Fig. 2 shows ways to make it easier to work with a pencil by hand.
An angle of 45 is easy to construct by dividing the right angle in half (Fig. 2, a). To construct an angle of 30°, you need to divide the right angle into three equal parts (Fig. 2, b).
A regular hexagon can be drawn in isometry (Fig. 2, c), if on an axis located at an angle of 30°, a segment equal to 4a, and on the vertical axis - 3.5a. This is how we get the points that define the vertices of a hexagon whose side is equal to 2a.
To describe a circle, you first need to apply four strokes on the center lines, and then four more between them (Fig. 2, d).
It is not difficult to construct an oval by inscribing it into a rhombus. To do this, strokes are applied inside the rhombus to mark the line of the oval (Fig. 2, e), and then the oval is outlined.
Rice. 2. Constructions that facilitate the execution of technical drawings
The technical drawing can be performed in the following sequence.
1. In the place selected in the drawing, axonometric axes are constructed and the location of the part is outlined, taking into account its maximum visibility (Fig. 3, a).
2. Mark the overall dimensions of the part, starting from the base, and build a volumetric parallelepiped that covers the entire part (Fig. 3, b).
3. The dimensional parallelepiped is mentally divided into the individual geometric shapes that make it up, and they are highlighted with thin lines (Fig. 3, c).
4. After checking and clarifying the correctness of the marks made, draw lines of the required thickness around the visible elements of the part (Fig. 3, d, e).
5. Select a shading method and perform the appropriate completion of the technical drawing (Fig. 3, e).
Rice. 3. Sequence of technical drawing.
When making a drawing not according to a drawing, but from nature the sequence of execution remains the same, only the dimensions of all parts of the object are determined by applying a pencil or a strip of thick paper to the part of the object being measured (Fig. 4, a).
Rice. 4. Drawing from life
If the drawing needs to be made in a reduced size, then an approximate measurement of the dimensions is carried out as shown in Fig. 4, b, the pencil is held on outstretched arm between the observer's eye and the object. The further the part is moved, the smaller the dimensions will be.
Hatching on a technical drawing
To increase clarity and expressiveness, to give volume, apply to the completed technical drawing shading(Fig. 5). The application of chiaroscuro to a technical drawing, showing the distribution of light on the surfaces of the depicted object, is called shading. In this case, it is assumed that light falls on the object top left. Illuminated surfaces are left light, shaded surfaces are covered with shading, which is more frequent the darker the surface of the object. Hatching is applied parallel to some generatrix or parallel to the axes of projections. In Fig. 5, and a technical drawing of a cylinder is shown, on which the shading is made parallel hatching (solid parallel lines of varying thickness), in Fig. 5,b— scouring (hatching in the form of a grid), and in Fig. 5, in - using points (with increasing illumination, the distance between points increases).
Shading on working drawings of parts can also be done by shading - frequent, almost continuous application of strokes in different direction, or a wash made with ink or paint.
In each drawing, one particular method of shading is used, and all surfaces of the depicted object are shaded.
Fig.5. Applying shading
In Fig. Figure 6 shows a technical drawing of a part with shading made by parallel hatching.
Rice. 6. Technical drawing with shading
You can apply shading not to the entire surface, but only in places that emphasize the shape of the object (Fig. 7).
Rice. 7. Technical drawing with simplified shading
A technical drawing in its finished form with shadowing and shading can sometimes be more visual than an axonometric image and, with dimensions applied, can replace a drawing of a simple part that serves as a document for its manufacture. This makes it possible to explain drawings of complex objects in a more accessible and intelligible way.
Part sketch
Design documents for one-time use can be made in the form of sketches.
Sketch- a drawing made without the use of a drawing tool (by hand) and strict adherence to a standard scale (on an eye scale). At the same time, the proportion in the sizes of the individual elements and the entire part as a whole must be maintained. In terms of content, sketches are subject to the same requirements as working drawings.
Sketches are made when drawing up a working drawing of an existing part, when designing a new product, finalizing the design of a prototype product, if it is necessary to manufacture a part according to the sketch itself, when a part breaks during operation, if there is no spare part available, etc.
When making a sketch, all the rules established by GOST ESKD, as for the drawing, are observed. The only difference is that the sketch is made without the use of drawing tools. A sketch requires the same careful execution as a drawing. Despite the fact that the ratio of the height to the length and width of the part is determined by eye, the dimensions indicated on the sketch must correspond to the actual dimensions of the part.
In Fig. 8, a and b show a sketch and drawing of the same part. It is convenient to make sketches on checkered paper standard format, soft pencil TM, M or 2M.
Rice. 8. Comparison of sketches and drawing:
a - sketch; b - drawing
Sequence of sketch execution
Before completing the sketch you need to:
1. Inspect the part and become familiar with its design (analyze the geometric shape, find out the name of the part and its main purpose).
2. Determine the material from which the part is made (steel, cast iron, non-ferrous metals, etc.).
3. Establish a proportional ratio of the sizes of all elements of the part to each other.
4. Select a format for the part sketch, taking into account the number of images, the degree of complexity of the part, the number of dimensions, etc.
The sketch of the part is shown in Figure 9:
1. Apply an internal frame and main inscription to the format;
2. select the position of the part relative to the projection planes, determine the main image of the drawing and the minimum number of images that allow you to fully identify the shape of the part;
3. select the scale of the images by eye and perform the layout: thin lines mark the overall rectangles - places for future images (when arranging, space is left between the overall rectangles for setting dimensions);
4. if necessary, axial and center lines are applied and images of the part are drawn (the number of views should be minimal, but sufficient for the manufacture of the part);
5. draw the contours of the images: external and internal (circle the images);
6. draw dimension and extension lines;
7. measure the part with various measuring instruments (Fig. 10-12). The resulting dimensions are applied above the corresponding dimension lines;
8. fulfill the necessary inscriptions (technical requirements), including the main inscription;
9. check the correctness of the sketch.
Rice. 9. Sequence of sketch construction
Part measurement
Measuring a part when sketching it from life is carried out using various tools, which are selected depending on the size and shape of the part, as well as the required sizing accuracy. A metal ruler (Fig. 10, a), calipers (Fig. 10, b) and a bore gauge (Fig. 10, c) allow you to measure external and internal dimensions with an accuracy of 0.1 mm.
Rice. 10
A caliper, a limit bracket, a gauge, a micrometer allow you to perform a more accurate measurement (Fig. 11, a, b, c, d).
Rice. 11
The radii of roundings are measured using radius templates (Fig. 12, a), and thread pitches are measured using thread templates (Fig. 12, b, c).
Rice. 12
In Fig. Figure 13 shows how the linear dimensions of a part are measured using a ruler, calipers and bore gauge.
A sketch is a design document made by hand, without the use of drawing tools, without exact adherence to scale, but with mandatory observance of the proportions of the elements of the parts. The sketch is a temporary drawing and is intended for one-time use.
The sketch must be drawn up carefully in compliance with projection connections and all the rules and conventions established by the ESKD standards.
A sketch can serve as a document for the manufacture of a part or for the execution of its working drawing. In this regard, the sketch of the part must contain all the information about its shape, size, surface roughness, and material. The sketch also contains other information, presented in the form of graphic or text material (technical requirements, etc.).
Sketching (sketching) is carried out on sheets of any standard size paper. In educational settings, it is recommended to use checkered writing paper.
The sketching process can be divided into separate stages, which are closely related to each other. In Fig. 367 shows a step-by-step sketch of the “support” part.
I. Familiarization with the part
Upon familiarization, the shape of the part is determined (Fig. 368, a and b) and its main elements (Fig. 368, c), into which the part can be mentally divided. If possible, the purpose of the part is clarified and a general idea about the material, processing and roughness of individual surfaces, about the manufacturing technology of the part, about its coatings, etc.
II. Selecting the main view and other required images
The main view should be chosen so that it gives the most complete idea of the shape and dimensions of the part, and also facilitates the use of the sketch during its manufacture.
There are a significant number of parts limited by surfaces of rotation: shafts, bushings, sleeves, wheels, disks, flanges, etc. In the manufacture of such parts (or workpieces), processing is mainly used on lathes or similar machines (rotary, grinding).
The images of these parts in the drawings are positioned so that in the main view the axis of the part is parallel to the main inscription. This arrangement of the main view will make it easier to use the drawing when manufacturing parts based on it.
If possible, you should limit the number of invisible contour lines that reduce the clarity of images. Therefore, attention should be paid special attention the use of cuts and sections.
The required images should be selected and performed in accordance with the rules and recommendations of GOST 2.305-68.
In Fig. 368, a and b, options for the location of the part are given and the arrows show the direction of projection, as a result of which it can be obtained main view. Preference should be given to the position of the part in Fig. 368, b. In this case, the view on the left will show the outlines of most of the elements of the part, and the main view itself will give the clearest idea of its shape.
IN in this case Three images are enough to represent the shape of the part: main view, top view and left view. A frontal incision should be made at the site of the main view.
III. Selecting a Sheet Size
The sheet format is selected according to GOST 2.301-68 depending on the size of the images selected during stage II. The size and scale of the images must allow all elements to be clearly reflected and the necessary dimensions and symbols to be applied.
IV. Sheet preparation
First, you should limit the selected sheet to an outer frame and draw a drawing frame of a given format inside it. The distance between these frames should be 5 mm, and a 20 mm wide margin is left on the left for filing the sheet. Then the outline of the frame of the main inscription is applied.
V. Arrangement of images on a sheet
Having chosen the visual scale of the images, the ratio of the overall dimensions of the part is established by eye. In this case, if the height of the part is taken as A y, then the width of the part is B^A, and its length is C«2L (see Fig. 367, a and 368, b). After this, rectangles with the overall dimensions of the part are drawn in thin lines on the sketch (see Fig. 367, a). The rectangles are positioned so that the distances between them and the edges of the frame are sufficient for applying dimension lines and symbols, as well as for placing technical requirements.
The layout of images can be facilitated by using rectangles cut from paper or cardboard and having sides corresponding to the overall dimensions of the part. By moving these rectangles around the drawing field, the most suitable location of the images is selected.
VI. Drawing images of part elements
Inside the resulting rectangles, images of the elements of the part are drawn with thin lines (see Fig. 367, b). In this case, it is necessary to maintain their proportions
sizes and ensure projection connection of all images by drawing appropriate axial and center lines.
VII. Design of views, sections and sections
Next, in all views (see Fig. 367, c), details that were not taken into account when performing stage VI (for example, roundings, chamfers) are clarified and removed auxiliary lines construction. In accordance with GOST 2.305-68, cuts and sections are drawn up, then a graphic designation of the material is applied (hatching of sections) in accordance with GOST 2.306-68 and the images are outlined with the corresponding lines in accordance with GOST 2.303-68.
VIII. Drawing dimension lines and symbols
Dimensional lines and conventional signs, which determine the nature of the surface (diameter, radius, square, taper, slope, type of thread, etc.), are applied according to GOST 2.307-68 (see Fig. 367, c). At the same time, the roughness of individual surfaces of the part is marked and symbols are applied to determine the roughness.
IX. Applying dimensional numbers
Using measuring tools, determine the dimensions of the elements and apply dimensional numbers on the sketch. If the part has a thread, then it is necessary to determine its parameters and indicate the corresponding thread designation on the sketch (see Fig. 367, d).
X. Final design of the sketch
When finalized, the main inscription is filled in. If necessary, information is provided on the maximum deviations of the dimensions, shape and location of surfaces; technical requirements are drawn up and explanatory notes are made (see Fig. 368, d). Then a final check of the completed sketch is made and the necessary clarifications and corrections are made.
When sketching a part from life, you should be critical of the shape and arrangement of its individual elements. For example, casting defects (uneven wall thicknesses, displacement of hole centers, uneven edges, asymmetry of parts of a part, unreasonable tides, etc.) should not be reflected in the sketch. Standardized elements of the part (grooves, chamfers, drilling depth for threads, roundings, etc.) must have the design and dimensions provided for by the relevant standards.
Technical drawing is a visual image that has the basic properties of axonometric projections or a perspective drawing, made without the use of drawing tools, on a visual scale, in compliance with proportions and possible shading of the form.
Technical drawings have long been used by people to reveal creative concept. Take a closer look at Leonardo da Vinci’s drawings, which so fully reveal the design features of a device or mechanism that you can use them to make drawings, develop a project, or manufacture an object in material (Fig. 123).
Engineers, designers, architects, when designing new models of equipment, products, structures, use technical drawing as a means of fixing the first, intermediate and final options technical solutions. In addition, technical drawings serve to verify correct reading complex shape shown in the drawing. Technical drawings are necessarily included in the set of documentation prepared for transfer to foreign countries. They are used in technical passports products.
Rice. 123. Technical drawings by Leonardo da Vinci
Rice. 124. Technical drawings of parts made of metal (a), stone (b), glass (c), wood (d)
A technical drawing can be performed using the central projection method (see Fig. 123), and thereby obtain a perspective image of an object, or the parallel projection method (axonometric projections), constructing a visual image without perspective distortions (see Fig. 122).
Technical drawing can be performed without revealing the volume by shading, with shading of the volume, as well as conveying the color and material of the depicted object (Fig. 124).
In technical drawings, it is allowed to reveal the volume of objects using the techniques of shading (parallel strokes), scribbling (strokes applied in the form of a grid) and dot shading (Fig. 125).
The most commonly used technique for identifying the volume of objects is shaking.
It is generally accepted that rays of light fall on an object from the top left (see Fig. 125). Illuminated surfaces are not shaded, while shaded surfaces are covered with shading (dots). When shading shaded areas, strokes (dots) are applied with the smallest distance between them, which makes it possible to obtain denser shading (dot shading) and thereby show shadows on objects. Table 11 shows examples of shape detection geometric bodies and details using shattering techniques.
Rice. 125. Technical drawings revealing volume by shading (a), scribbling (b) and dot shading (e)
11. Shading the shape using shading techniques
Technical drawings are not metrically defined images unless they are marked with dimensions.
In cases where it is necessary to quickly explain the shape of the object in question, to show it clearly, a technical drawing is used. Technical drawing called a visual image of an existing or designed object, made without the use of drawing tools, by hand on an eye-size scale, observing the proportions and sizes of the elements that make it up. Technical drawings used in design practice are used to more quickly express your thoughts in a visual form. This makes it possible to explain drawings of complex objects in a more accessible and intelligible way. The use of technical drawing allows you to consolidate a technical idea or proposal. In addition, the use of a technical drawing of a part is very useful when sketching parts from life, although a technical drawing can also be made using a complex drawing of an object.
The most important requirement for a technical drawing is clarity. A technical drawing in its finished form with shadowing and shading can sometimes be more visual than an axonometric image and, with dimensions applied, can replace a drawing of a simple part that serves as a document for its manufacture.
In order to quickly and correctly complete a technical drawing, it is necessary to acquire the skills of drawing parallel lines at different angles, at different distances, of different thicknesses without the use of drawing tools, without using instruments, dividing segments into equal parts, constructing the most used angles (7,15, 30 ,41,45,60,90°), divide angles into equal parts, build circles, ovals, etc. It is necessary to have an idea of the image of various figures in each of the projection planes, to be able to create images of the most used flat figures and simple geometric ones in a technical drawing forms
Before starting the technical drawing, the issue of choosing the most effective visual image system is decided. In mechanical engineering drawing, rectangular isometry is most often used for this purpose. This is explained by the fact that the outlines of figures located in axonometric planes undergo the same distortion in isometry, which ensures the clarity of the image and comparative simplicity her achievements. Rectangular dimetry is also used.
In Fig. 297, A technical drawing is shown right triangle, located in the horizontal plane of projections and made in rectangular isomerism, and in Fig. 297, b- technical drawing of a right triangle located in the frontal plane of projections and made in rectangular dimetry.
In Fig. 298, A shows a technical drawing of a hexagon located in the horizontal projection plane and made in rectangular isometry. In Fig. 298, b A technical drawing of the same hexagon, made in rectangular diameter, is shown. The drawing of a circle located in
horizontal plane of projections (Fig. 299, a), and a technical drawing of the same circle located in the frontal plane of projections and made using the rules of rectangular dimetry (Fig. 299, b).
Using the rules for constructing axonometric projections and technical drawings of the simplest flat figures, you can begin to make technical drawings of volumetric geometric figures.
In Fig. 300, A The technical drawing of a straight tetrahedral pyramid, made in rectangular isomerism, is shown in Fig. 300, b- technical drawing of a straight tetrahedral pyramid, made in rectangular dimensions.
Carrying out technical drawings of surfaces of revolution involves the construction of ellipses. In Fig. 301, and a technical drawing of a right circular cylinder is shown, made in rectangular isomerism, and in Fig. 301, b- a drawing of a straight circular cone, made in rectangular dimensions.
The technical drawing can be performed in the following sequence.
1. In the place selected in the drawing, axonometric axes are constructed and the location of the part is outlined, taking into account its maximum visibility (Fig. 302, a).
2. Mark the overall dimensions of the part, starting from the base, and build a volumetric parallelepiped that covers the entire part (Fig. 302, b).
3.
The dimensional parallelepiped is mentally divided into the individual geometric shapes that make it up, and they are highlighted with thin lines (Fig. 302, c).
4. After checking and clarifying the correctness of the outlines made, draw lines of the required thickness around the visible elements of the part (Fig. 302, d, e).
5. Select a shading method and complete the appropriate drawing of the technical drawing (Fig. 302, e). In Fig. 302 shows the sequence of constructing a technical drawing of a ttetel.
To increase clarity and expressiveness, solid shading is applied to the completed technical drawing. parallel lines of varying thickness or grid-like shading. The application of chiaroscuro to a technical drawing, showing the distribution of light on the surfaces of the depicted object, is called shading. Shading can also be done using dots. With increasing illumination, the distance between points increases. When performing shading, it is believed that the light falls on the depicted object from above, behind and from the left, so the illuminated parts are made lighter, and the right and lower parts are made darker. Closer to
the placed parts of the object are shaded lighter than areas located further from the light. In each drawing, one particular method of shading is used, and all surfaces of the depicted object are shaded.
In Fig. 303, A a technical drawing of a cylinder is shown, on which the shading is done by parallel shading, in Fig. 303, b- by tracing, and in Fig. 303, V- using dots. In Fig. 302, e shows a technical drawing of a part with shading made by parallel shading.
Shading on working drawings of parts can also be done by shading - frequent, almost continuous application of strokes in different directions, or by washing, made with ink or paint.
