-state the differences between hand and machine tool with the stated example. Hammer, mallet, screw driurs as hand tools.
Machine tools are powered
Form of screw thread, square thread
Electricity e.g. power lack saw, drilling machines
Form of screw thread, SQUARE THREAD ACME, thread Buttress thread
Use chart to demonstrate the screw thread form.
Mention and sketch some screw thread and state
where they should be used.
SS 2 SECOND TERM
TOPIC AND CONTENT
Definition of arc welding.
Basic types of arc welding.
(i)Non consumable electrode arc welding.
(ii) Consumable electrode arc welding.
Defines arc welding and write down the principle involved in establishing the arc.
Mention basic types of arc welding and give students work pieces of a given dimension with an electrode to weld a butt joint.
Consumable electrode arc overcalling,
Definition of arc welding
-maintenance of the arc.
-metal transfer across the arc.
Defines arc welding. students scratch the electrodes on the parent metal with draw it to a height arc length (1.5m) and maintains it at that length through out the weld.
Shielded metal arc welding (swam),
-principle of operation
(I) D.c transformer.
(iii)Flexible cable electrode.
Explain the principle of operation of (SMAW)
Show the SMAW equipment to students and ask them to put them into use in the workshop
-Using electrode connected to the electrode holder.
-connect the electrode holder to the feasible able which leads directly into the transformer. The D.C.
State the source of supply of the AC
-Explain how rectifier reduces the AC connect to the welding connect.
Striking the arc, Taping method
In order to establish an:-There are two methods which involves touching the electrode with the base metal and with drawing it to a length for the arc to be established scratching motion involves scratched the electrode on the parent metal in the motion the marches is being scratched.
Function of electrode coating
Classification of electrode
State that the flux coating prevents the weld from at mospheric contamination and for protective should on the weld.
Classify electrodes according to welding conditions.
Essential factors for maintaining high quality weld.
In maintaining high quality weld student must select connect size of electrode to suit connect .maintaining the speed of the weld and angle inclination of the electrode.
Arc welding position ,
Arc welding joint ,
Explain the welding position and state the factors that governs the process
-place mild steel plate of specified size for student to weld in horizontal position, overhead position and overhead position
-types and use
-sheet metal work
Teacher mentions the various types of rivet and state their uses and where they are important
State the advantage of rivet joints students should produce various rivet and drill mild steel plate to have a round hole the hammer them together to have a rivet joint by loud. Use also machine to loud machine rivet.
Basic sheet metal work hand tools and equipments. Sheet metal work operation:-
Hand shares (snips)
Bench tools: stakes, Bick, iron, Hammer, Mattets etc.
Demonstrate the cutting of sheet metals using guillotine, use bending rollers to bend the sheet metal. Ask students to use universal jenny folding machine folding student should use hammer and mallets to beat the folded metals to shape for finishing.
(A)method of pattern development radial line, triangulation parallel line
(B)types of pattern:-rectangular, plain, cylindrical, conical section.etc.
-internal gridding and surface grinding.
Cut their sheet of mild steel plate and flanch the edge bend, the edges for safety and use wire for rounding up the bottom. And mallet it down. to shape (wired edge)
Work out the bending allowance for the know up joints, bend the metal to the shape required and use ships to cut the excess metal away for tarnishing.
Explain method of pattern development state types of patterns used for plain, cylindrical and conical sections etc.
-Develop simple patterns of shape using parallel lines radial and triangulation method and transfer it to the work piece.
Demonstrate the grinding operation using the grinding disk for both internal and external surface.