Why is it difficult to cut sheet metal with blunt scissors
Slide captions:
Basic techniques for cutting thin sheet metal and wire. Technology teacher Chushkin A.A. MOU SOSH 24 2013 Volgograd.
Questions 1. Types of tools for cutting metal and wire. 2. Types of locksmith scissors and their difference. 3. The use of locksmith scissors. 4. Nippers, their structure and principle of operation. 5. Industrial devices for cutting metal and wire.
Types of Tools for Cutting Metal and Wire 1. Locksmith’s scissors are used to cut sheet metal. 2. Cutting wire using wire cutters.
Types of locksmith scissors Scissors differ depending on the shape of the blade. 1. Straight lines 2. Curves
Using locksmith scissors Cutting thin sheet metal with scissors can be performed directly on the workbench table by hand (Fig. A) and in a vise (Fig. B). When cutting, the blade is guided exactly at the risk, and the workpiece is slightly raised and pressed against the scissors.
Nippers, their structure and principle of operation. Nippers are used to cut steel, copper or aluminum wire with a diameter of up to 3 millimeters. The nippers have handles and jaws. The blades of the sponges move towards each other and cut the wire.
Industrial devices for cutting metal and wire. In factories, mechanical shears are used to cut sheet metal and large diameter bars. They are guillotine and disc. The cutting process with guillotine shears is the same as when cutting with hand shears. In disc shears, sheet metal is cut with the sharp edges of rotating discs.
Work with materials Stage 1: independent work on the application of new knowledge. the formation of a material image of the scan of a box made of cardboard Stage 2: independent work on the manufacture of a scan of a box from Thin sheet metal.
Test questions: 1. How are locksmith’s scissors and nippers similar? 2. What rules must be followed when cutting sheet metal and wire? 3. Why is it difficult to cut sheet metal with blunt scissors? 4. Why should the sheet workpiece be periodically rearranged closer to the axis of the scissors during cutting? 5. Name the types of industrial shears for cutting sheet metal. 6. What is the difference between industrial mechanical shears and hand locksmiths? 7. Why, when cutting small pieces of wire with wire cutters, you need to direct the bite-off part towards the protective screen of the workbench?
Textbook “Technology” grade 5, ed. V.D.Simonenko. Yandex pictures. http://images.yandex.ru
Basic techniques for cutting thin sheet metal and wire. presentation for the lesson on technology (grade 5) on the topic
The material is intended for conducting technology lessons: “Techniques for cutting thin sheet metal and wire” with a repetition of the topic covered “Marking of thin sheet metal and wire”
methodological developments, presentations and notes
Presentation on “Cutting Thin Sheet Metal”.
Development of the lesson “Workplace of a locksmith. Types of metals and their main properties. Thin sheet metal and wire” is presented in the form of a methodological table, attachments with handouts.
The presentation is intended to teach how to read drawings of sheet metal and wire parts and techniques for straightening sheet metal and wire.
Lesson “Thin sheet metal and wire. Picture of thin sheet metal parts”. 5th grade.
I presented a presentation on technology in grade 5 on the topic Basic techniques for cutting thin sheet metal and wire.
Cutting techniques and cleaning of sheet metal and wire parts.
Technological map of technology lesson 5th grade. Acquaintance with the types of sheet metal and wire.
Section 25. Cutting workpieces made of sheet metal, wire and plastic materials
The workpiece is marked out. Now it can be cut, cut.
For cutting thin sheet metal in training workshops, metal scissors or scissors are used (see Fig. 96, e). Scissors should be sharpened and adjusted to cut, not crush metal.
Fig. 112. Locksmith scissors: 1. handles; 2. blades; 3. screw
Cut a piece of tin with a thickness of 0.2. 0.3 mm (material of cans) can be done on a locksmith’s workbench, holding it with your left hand. During cutting, the sheet is slightly raised above the table and constantly pressed against the blades of the scissors. In this case, the blades cannot be reduced to the end.
Fig. 113. Cutting a workpiece from tin on a workbench table
When cutting in a straight line with the mowing line, the blade of the tool is guided exactly along the line of the mowing line. If you need to get a circle from a metal plate (Fig. 114, a), then cut along the outer contour, departing from the mowing line of the marking by about 1 mm. The resulting allowance is then removed during stripping.
Fig. 114. Cutting a circle (a) and holes (b): 1. locksmith’s scissors; 2. blank; 3. technological hole
If it is necessary to make a round hole in the workpiece (Fig. 114, b), then a small (technological) hole for the scissors is pre-drilled inside the marked circle. Then cut with scissors, stepping back from the mowing line of the marking inside the circle 1 mm.
It is more convenient and easier to cut the workpiece if one handle of the scissors is fixed in a vice
Fig. 115. Cutting thin sheet metal with scissors fastening in a vice Mild steel, aluminum and copper wires up to 3 mm in diameter are cut with wire cutters or pliers using the side groove
How to Cut Thin Metal Precisely. Kevin Caron
Fig. 116. Cutting wire with wire cutters
If you need to cut off a small piece of wire, then the cut part is directed towards the protective mesh of the workbench.
Fig. 117. Cutting the wire using the side groove of the pliers: 1. pliers; 2. wire; 3. side grooves
When a workpiece made of tin or wire has already been cut off, it is straightened and the sharp edges obtained after cutting are cleaned.
In industrial plants, sheet metal and large diameter rods are cut with mechanical shears. Figure 118 shows guillotine shears with which you can cut sheet metal with a thickness of 0.3 to 40 mm and a width of 3 m. Workpiece 2 is advanced along table 5 until it stops, maintaining the required size I of the cut part of the workpiece. Press 4 press the workpiece to the table, after which, using a special mechanism, lower the movable knife 1 down and cut the workpiece.
Fig. 118. The principle of operation of the guillotine shears: 1. movable knife; 2. blank; 3. fixed knife; 4. clamp; 5. table
Plastic, such as polyethylene, up to 1.2 thick. 1.3 mm can be cut with ordinary scissors, thicker. with a jigsaw or a hacksaw for metal. Organic glass and getinax, as more fragile materials, also use a jigsaw and a hacksaw. Styrofoam is well cut with an ordinary knife.
Safe work rules
- It is imperative to wear a mitten on the hand holding the workpiece during cutting; do not hold this hand close to the cutting site.
- Beware of sharp edges of blanks and wires.
- When cutting the wire, do not bring it close to your face.
- When cutting sheet metal, securely fix the handle of the locksmith’s scissors in a vice.
- Handle locksmith scissors and nippers only with handles away from you.
Getting to know the professions
Carver. a specialist in cutting metal blanks, working in the blank production of the enterprise. He is well versed in the properties of various metals and alloys, knows the device of various types of mechanical shears, knows how to maintain and screw them up. Can qualitatively cut workpieces by marking or by adjusting the equipment to the desired size in accordance with the drawing.
Presentation on the topic Basic Techniques for Cutting Thin Sheet Metal and Wire Grade 5
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Basic Techniques for Cutting Thin Sheet Metal and Wire.
Technology teacher Chushkin A.A. MOU SOSH 242013 Volgograd.
Types of tools for cutting metal and wire. 2. Types of locksmith scissors and their difference. 3. The use of locksmith scissors. 4. Nippers, their structure and principle of operation. 5. Industrial devices for cutting metal and wire.
Types of tools for cutting metal and wire
Metal shears are used to cut sheet metal. 2. Cutting wire using wire cutters.
The scissors differ depending on the shape of the blade. 1. Straight lines 2. Curves
Cutting of thin sheet metal with scissors can be performed directly on the workbench table by hand (fig. A) and in a vise (fig. B). When cutting, the blade is guided precisely over the risk, and the workpiece is slightly raised and pressed against the scissors.
Nippers, their structure and principle of operation.
Nippers are used to cut steel, copper or aluminum wire with a diameter of up to 3 millimeters. The nippers have handles and jaws. The blades of the sponges move towards each other and cut the wire.
Industrial devices for cutting metal and wire.
In factories, mechanical shears are used to cut sheet metal and large diameter bars. They are guillotine and disc.
The cutting process with the guillotine shears is the same as when cutting with the hand shears.
In disc shears, sheet metal is cut with the sharp edges of rotating discs.
Stage 1: independent work on the application of new knowledge. the formation of a material image of the scan of a box made of cardboard; Stage 2: independent work on the manufacture of a scan of a box made of thin sheet metal.
Safety when working with scissors
How are locksmiths and wire cutters alike? 2. What rules must be followed when cutting sheet metal and wire? 3. Why is it difficult to cut sheet metal with blunt scissors? 4. Why should the sheet workpiece be periodically rearranged closer to the axis of the scissors during cutting? 5. Name the types of industrial shears for cutting sheet metal. 6. What is the difference between industrial mechanical shears and hand locksmiths? 7. Why, when cutting small pieces of wire with wire cutters, you need to direct the bite-off part towards the protective screen of the workbench?
Presentation on topic: Cutting thin sheet metal and wire
Cutting sheet metal and wire
Test your knowledge 1. What tools and equipment are used when cutting sheet metal and wire?
Test your knowledge 2. What do locksmiths and wire cutters have in common? A. the principle of operation of the cutting elements B. handles and cutting jaws C. purpose
Test your knowledge 3. Why do scissors sometimes crease rather than cut when cutting thin sheet metal? A. a large gap between the cutting knives of the scissors; blunt knives of the scissors B. insufficient pressure applied to the handles of the scissors B. the surface of the sheet metal is not cleaned of rust
Test your knowledge 4. Why is it difficult to cut sheet metal with blunt scissors? A. because applying additional efforts when cutting, hand B gets tired. because blunt knives wrinkle when cutting sheet metal, but sharp ones. cut B. because you have to cut sheet metal in the same place several times Cutting sheet metal with metal shears
Test your knowledge 5. Why should the blank be periodically moved closer to the axis of the scissors when cutting? A. because when cutting sheet metal, the cut line leaves the marking closer to the middle of the workpiece B. because you can break the tool C. because when cutting it is very difficult to hold the workpiece Marking a plane metal part according to a template
Test your knowledge 6. Cutting of workpieces at the enterprise is performed by A. metal cutters B. designers C. constructors Sheet metal cutting at the enterprise
Test your knowledge 7. What are the types of industrial shears for cutting sheet metal and large diameter bars? A. mechanical shears of guillotine and disc type B. special locksmith shears B. shaped and circular
Test your knowledge 8. What is the difference between industrial mechanical shears and hand locksmiths? A. dimensions B. drive and structure B. weight Mechanical guillotine shears Manual locksmiths Shears disc-type mechanical shears
Test your knowledge 10. What rules are observed when cutting metal with metal scissors? A. workpieces should be fixed firmly, but with smooth rotation of the vise screw handle B. do not touch the cut edges of the workpiece with bare hands C. do not guide the cutting blade with your finger. Use for these purposes wooden blocks, special stops Checking the quality of the work performed
Test your knowledge 11. How does a hand-held locksmith’s scissors differ from scissors for cutting paper and fabric? A. dimensions, weight; B. handles, dimensions, principles of operation; B. cutting knives. design Locksmith scissors Scissors for paper, fabric
Test your knowledge 12. What defects are possible on the workpiece when cutting it with blunt scissors? scissors with loose blades? A. the line of the cut is wrinkled, torn B. the line of the cut does not match the mowing line of the marking C. the line of the cut is wavy Cutting strips of thin sheet metal with metal scissors
Test your knowledge 13. Why can’t the scissor blades be pulled back when cutting thin sheet metal? A. there will be butt burrs on the mowing line of the cut B. cutting time increases C. the scissors become blunt quickly Cutting thin sheet metal with metal shears
Annotation to the presentation
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Presentation on “Cutting Thin Sheet Metal and Wire
Test your knowledge
What tools and equipment are used when cutting sheet metal and wire? Drill Hand vise Center punch Marking compass Hammer Locksmith scissors Vise Nippers
B. purpose 2. What do locksmith’s scissors and wire cutters have in common? A. the principle of the cutting elements B. handles and cutting jaws Think right. Think about it. Locksmith scissors Nippers
B. the surface of thin sheet metal is not cleaned of rust 3. Why do scissors sometimes crumple when cutting thin sheet metal, but not cut? A. a large gap between the cutting knives of the scissors; dull scissors blades B. insufficient pressure applied to the scissors handles Think right. Think.
Why is it difficult to cut sheet metal with blunt scissors? A. because applying additional efforts when cutting, hand B gets tired. because blunt knives wrinkle when cutting sheet metal, but sharp ones. cut B. because you have to cut sheet metal in the same place several times. Think. Think correctly. Cutting sheet metal with metal shears
B. because it is very difficult to hold the workpiece during cutting 5. Why should the sheet workpiece be periodically rearranged closer to the axis of the scissors during cutting? A. because when cutting sheet metal, the cut line leaves the marking closer to the middle of the workpiece B. because you can break the tool. Think Right. Think about it. Marking a planar metal part using a template
C. designers 6. Cutting of workpieces at the enterprise is performed A. metal cutters B. designers Think right. Think about it. Sheet metal cutting in the enterprise
B. shaped and circular 7. What are the types of industrial shears for cutting sheet metal and large diameter bars? A. mechanical shears of guillotine and disc type B. special locksmiths shears Think right. Think.
What is the difference between industrial mechanical shears and hand locksmiths? A. dimensions B. drive and construction B. weight Think. Think correctly. Mechanical guillotine shears Manual locksmiths Shears Disc-type mechanical shears
What rules are followed when cutting metal with metal shears? A. the workpieces should be fixed firmly, but by smooth rotation of the vise screw handle B. you must not touch the cut edges of the workpiece with your bare hands; C. you must not guide the cutting blade with your finger. Use wooden blocks for these purposes, special stops Think. Think correctly. Checking the quality of the work performed
How are hand-held locksmiths scissors different from scissors for cutting paper and fabric? A. dimensions, weight; B. handles, dimensions, operating principles; B. cutting knives. design Think. Think correctly. Scissors for paper, fabric Locksmith scissors
В. the line of the cut is wavy 12. What defects are possible on the workpiece when cutting it with blunt scissors? scissors with loose blades? A. the line of the cut is wrinkled, torn B. the line of the cut does not match the mowing line of the marking. Think correctly. Think about it. Cutting strips of sheet metal with metal shears
B. the scissors dull quickly 13. Why can’t the scissor blades be brought down to the end when cutting thin sheet metal? A. there will be butt burrs on the mowing line of the cut B. cutting time will increase. Think right. Think about it. Cutting sheet metal with metal shears
Presentation: “Cutting thin sheet metal and wire
Description of the presentation for individual slides:
Cutting sheet metal and wire
Test your knowledge 1. What tools and equipment do you use when cutting sheet metal and wire? Drill Hand vise Center punch Marking compass Hammer Locksmith scissors Vise Nippers
Test your knowledge Q. purpose 2. What do locksmith’s scissors and wire cutters have in common? A. the principle of the cutting elements B. handles and cutting jaws Think right. Think about it. Locksmith scissors Nippers
Test your knowledge Q. the surface of thin sheet metal is not cleaned of rust 3. Why do scissors sometimes crumple when cutting sheet metal, but not cut? A. a large gap between the cutting knives of the scissors; blunt knives of scissors B. insufficient pressure applied to the handles of the scissors Think right. Think.
Why is it difficult to cut sheet metal with blunt scissors? Test your knowledge A. because applying extra effort when cutting, hand B gets tired. because blunt knives crumple when cutting sheet metal, and sharp ones. cut B. because you have to cut sheet metal in the same place several times. Think. Think correctly. Cutting sheet metal with metal shears
Test your knowledge B. because it is very difficult to hold the workpiece when cutting 5. Why should the sheet workpiece be periodically moved closer to the axis of the scissors while cutting? A. because when cutting sheet metal, the cut line leaves the marking closer to the middle of the workpiece B. because you can break the tool. Think Right. Think about it. Marking a planar metal part using a template
Test your knowledge C. designers 6. Cutting of workpieces at the enterprise is performed A. metal cutters B. designers Think right. Think about it. Sheet metal cutting in the enterprise
Test your knowledge Q. shaped and circular 7. What are the types of industrial shears for cutting sheet metal and large diameter bars? A. mechanical shears of guillotine and disc type B. special locksmiths shears Think right. Think.
What is the difference between industrial mechanical shears and hand locksmiths? Test your knowledge A. dimensions B. drive and design C. weight Think. Think correctly. Guillotine type mechanical shears Hand locksmiths Shears Disc type mechanical shears
What rules are followed when cutting metal with metal shears? Test your knowledge A. the workpieces should be fastened firmly, but by smooth rotation of the vise screw handle B. you must not touch the cut edges of the workpiece with your bare hands C. you must not guide the cutting blade with your finger. Use for these purposes wooden blocks, special stops Think. Think correctly. Checking the quality of the work performed
How are hand-held locksmiths scissors different from scissors for cutting paper and fabric? Test your knowledge A. dimensions, weight B. handles, dimensions, operating principles C. cutting knives. design Think. Think correctly. Scissors for paper, fabric Locksmith scissors
Test your knowledge B. wavy cutting line 12. What defects are possible on the workpiece when cutting it with blunt scissors? scissors with loose blades? A. the line of the cut is wrinkled, torn B. the line of the cut does not match the mowing line of the marking. Think correctly. Think about it. Cutting strips of sheet metal with metal shears
Test your knowledge Q. scissors get dull quickly 13. Why can’t the scissor blades be cut to the end when cutting thin sheet metal? A. there will be butt burrs on the mowing line of the cut B. cutting time will increase. Think right. Think about it. Cutting sheet metal with metal shears
Cutting sheet metal and wire
Cutting sheet metal and wire
What do locksmiths and wire cutters have in common?
Why should the sheet blank during cutting be periodically rearranged closer to the axis of the shears?
Why should the sheet blank during cutting be periodically rearranged closer to the axis of the shears?
What are the types of industrial shears for cutting sheet metal and large diameter bars??
What is the difference between industrial mechanical shears and hand locksmiths?
Why, when cutting small pieces of wire with wire cutters, you need to direct the bite-off part towards the protective mesh of the workbench?
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Presentation “Cutting thin sheet metal and wire” (grade 6) by technology. project, report
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Presentation slides
Cutting sheet metal and wire
What tools and equipment are used when cutting thin sheet metal and wire?
What do locksmiths and wire cutters have in common?
B. the surface of thin sheet metal is not cleaned from rust
Why do scissors crumple rather than cut when cutting thin sheet metal??
A. a large gap between the cutting knives of the scissors; dull scissor knives
B. insufficient pressure applied to the handles of the scissors
Why is it difficult to cut sheet metal with blunt scissors?
A. because applying extra effort when cutting, the hand gets tired
B. because blunt knives crumple when cutting sheet metal, but sharp ones. cut
B. because you have to cut sheet metal in the same place several times
Cutting sheet metal with metal shears
B. because it is very difficult to hold the workpiece when cutting
Why should the sheet blank during cutting be periodically rearranged closer to the axis of the scissors??
A. because when cutting sheet metal, the cut line leaves the marking closer to the middle of the workpiece
B. because you can break the tool
Marking a planar metal part using a template
The cutting of workpieces at the enterprise is performed by
Sheet metal cutting in the enterprise
What are the types of industrial shears for cutting sheet metal and large diameter bars??
A. mechanical shears of guillotine and disc type
What is the difference between industrial mechanical shears and hand locksmiths?
Mechanical guillotine shears
B. so that the nippers do not break during work
Why, when cutting small pieces of wire with wire cutters, you need to direct the bite-off part towards the protective mesh of the workbench?
B. so that the flying piece of wire can be quickly found on the workbench lid
What rules are followed when cutting metal with metal scissors?
A. the workpieces should be fixed firmly, but by smooth rotation of the vise screw handle
B. do not touch the cut edges of the workpiece with bare hands
B. Do not guide the cutting blade with your finger. Use for these purposes wooden blocks, special stops
How hand locksmith scissors differ from scissors for cutting paper and fabric?
B. handles, sizes, principles of work
What defects are possible on the workpiece when cutting it with blunt scissors? scissors with loose blades?
B. the line of the cut does not match the mowing line of the marking
Cutting strips of sheet metal with metal shears
Why when cutting thin sheet metal, the scissor blades cannot be brought to the end ?
A. there will be butt burrs on the cut line
Cutting sheet metal with metal shears
Technology lesson on the topic “Cutting workpieces from sheet metal, wire and artificial materials
“Cutting workpieces from sheet metal, wire and plastic materials”
Section: “Technologies for manual and machine processing of metals and artificial materials”.
Purpose: to familiarize students with tools and devices for cutting workpieces made of thin sheet metal, wire and artificial materials, the rules and sequence of cutting workpieces of various thicknesses and shapes, rules of safe work; to form in fifth-graders the skills and abilities to qualitatively cut blanks from tin, wire and plastic according to the marking; develop accuracy, diligence and respect for structural materials.
Didactic teaching aids: workbench, locksmith scissors, hacksaws, jigsaws, nippers, pliers, vise, mittens, marked blanks made of sheet metal, wire, plastic for practical work 3, textbook (§ 25), workbook.
Teaching methods: story, conversation, frontal survey, demonstration of visual aids, work with a book, practical work.
Formed UUD: personal, cognitive, communicative.
Basic concepts: locksmiths scissors, wire cutters, cutter.
I. Repetition of the covered material.
II. Communication of the topic and purpose of the lesson.
Lesson topic: “Cutting workpieces from sheet metal, wire and artificial materials”.
The purpose of the lesson is to get acquainted with the technology of cutting blanks made of thin sheet metal, wire and artificial materials.
III. Presentation of new material.
The teacher shows the students tools and devices for cutting sheet metal, wire and plastic. Then he demonstrates how to properly hold a locksmith’s scissors, as well as techniques for cutting workpieces of various thicknesses on the workbench table and with securing the scissors in a vice, while focusing the students’ attention on the rules of safe work when cutting. After that, the teacher briefly introduces the students to the working profession. cutter.
The workpiece is marked out. Now it can be cut, cut.
For cutting thin sheet metal in training workshops, they use locksmith scissors or scissors for metal (see fig. 96, d). Scissors should be sharpened and adjusted to cut, not crush metal.
You can cut a workpiece made of tin with a thickness of 0.2 0.3 mm (material of cans) on a locksmith’s workbench, holding it with your left hand. During cutting, the sheet is slightly raised above the table and constantly pressed against the blades of the scissors. In this case, the blades cannot be reduced to the end.
When cutting in a straight line with the mowing line, the blade of the tool is guided exactly along the line of the mowing line. If you want to get a circle from a metal plate (fig. 114, but), then cut along the outer contour, departing from the mowing line of the marking by about 1 mm. The resulting allowance is then removed during stripping.
If it is necessary to make a round hole in the workpiece (Fig. 114, b), then a small (technological) hole for the scissors is pre-drilled inside the marked circle. Then cut with scissors, stepping back from the mowing line of the marking inside the circle 1 mm.
It is more convenient and easier to cut the workpiece if one handle of the scissors is fixed in a vice
Mild steel, aluminum and copper wires up to 3 mm in diameter are cut nippers or with pliers using the side groove
If you need to cut off a small piece of wire, then the cut part is directed towards the protective mesh of the workbench.
When a workpiece made of tin or wire has already been cut, it is straightened and the sharp edges obtained after cutting are cleaned.
In industrial plants, sheet metal and large diameter rods are cut with mechanical shears. Figure 118 shows guillotine shears that can cut sheet metal with a thickness of 0.3 to 40 mm and a width of 3 m. 2 promoted on the table five all the way, keeping the required size l cut off part of the workpiece. Clamp four press the workpiece to the table, after which, using a special mechanism, lower the movable knife down one and cut the workpiece.
Plastic, for example polyethylene, with a thickness of up to 1.2 1.3 mm can be cut with ordinary scissors, of greater thickness. with a jigsaw or a hacksaw for metal. Plexiglas and getinax are more fragile materials. also with a jigsaw and a hacksaw. Styrofoam is well cut with an ordinary knife.
It is imperative to wear a mitten on the hand holding the workpiece during cutting; do not hold this hand close to the cutting site.
Beware of sharp edges of blanks and wires.
When cutting the wire, do not bring it close to your face.
When cutting sheet metal, securely fix the handle of the locksmith’s scissors in a vice.
Handle locksmith scissors and nippers only with handles away from you.
Carver. a specialist in cutting metal blanks, working in the blank production of the enterprise. He is well versed in the properties of various metals and alloys, knows the device of mechanical shears of various types, knows how to maintain and adjust them. Can qualitatively cut workpieces by marking or by adjusting the equipment to the desired size in accordance with the drawing.
IV. Frontal poll on new material.
To consolidate the new material, students must complete task 23 in the workbook: determine the order of performing actions when cutting the part shown in Figure 98 from the textbook. The correct arrangement of numbers: 1, 5, 4, 2, 8, 3, 7, 6. After that, the students move on to doing practical work 3 from the textbook.
Cutting workpieces from sheet metal, wire, plastic materials
Distribute responsibilities within the group. Consider tools for cutting sheet metal, wire, plastic and prepare your work area for cutting.
Cut the previously marked blanks for the household scoop. soldering iron stands. propeller (see Appendix, Fig. 175), number for the apartment door and details of your design product.
Calculate the length and cut a piece of wire for the scribe (see fig. 97, in), screwdrivers (see Fig. 102), a wire ring with a diameter of Æ 140 mm for the propeller (see Appendix, Fig. 175, but), stands for books (see Appendix, fig. 176, but), and etc.
As part of Practice 3, each student should independently cut one piece of sheet metal, one of wire, and one of plastic.
The most common mistakes fifth graders make:
The teacher needs to be careful not to make such mistakes.
Approximate criteria for assessing the quality of work in the lesson:
1) error-free execution of task 23 in the workbook;
3) proper preparation of the workplace for cutting blanks;
4) the right choice of tools and devices for cutting;
5) compliance with the correct cutting techniques for thin sheet metal;
6) correct implementation of cutting techniques for wire and plastic blanks;
8) a high-quality cut out workpiece made of thin sheet metal;
9) high-quality cut wire blank;
10) coincidence of the cut out contours of the plastic workpiece with the marking lines.
In accordance with the requirements for the quality of work, the teacher draws up a protocol for analyzing the work of students on this topic.
During the lesson, the teacher constantly monitors students’ compliance with the rules of safe work when cutting blanks.
Setting and commenting marks for the lesson. At the end of the lesson, a comprehensive assessment is given based on the results of the frontal survey, the completion of task 23 in the workbook and practical work 3 from the textbook.
Correct answers to the task “Test yourself” “Cutting workpieces from sheet metal, wire and artificial materials”