4. Application of the working technique of ''Grinding of Simple Tools''

The exercises can follow the order given in the "Instruction examples for practical vocational training - Grinding of Simple Tools" for 5 (or, resp. 8) examples.

These "Instruction examples..." contain a list of materials (initial materials, hand tools, measuring and testing tools, accessories) as well as the sequence of operations for working or manufacturing the workpiece.

Thus, the trainees avail of all the necessary information to begin their exercise-related work.

4.1. Instruction examples

What follows is a brief description of the individual instruction examples in order to give a survey of those workpieces on which the previously acquired knowledge can be practised.

Instruction example 12.1.
Centre punch and scribing punch

Figure

This exercise serve to practise the simple sharpening technique of worn punches as well as the production of these two kinds of punches.

Instruction example 12.2.
Steel scriber

Figure

Similar to the practice involved in sharpening the punches, the trainees practise how to sharpen or to manufacture steel scribers professionally.

Instruction example 12.3.
Screw driver

Figure

The trainees practise the proper grinding of screw drivers.

The instructor underlines the importance of a slightly hollow-ground blade.

Instruction example 12.4.
Flat chisel and cape chisel

Figure

Based on the special requirements of parallelism and angularity of the cutting edges, the working technique of sharpening chisels is the main subject of this exercise.

Instruction 12.5.
Drills with standard drill point as well as flat drill point and centre point

Figure

This exercise serves to practise grinding of the two main types of drill points of drills for steel. The instructor gives special hints for avoiding typical grinding errors.

4.2. Criteria for practical training

It is recommended to determine some crucial points of evaluation and supervision. The following criteria can serve as a guideline

- Does the trainee employ the appropriate grinding wheel?
- Did he check the distances at the grinding machine?
- Punch and scriber:

· Does the trainee grind the tapered end with a horizontal position of the hand?
· Does the trainee grind the tapered end with a vertical position of the hand?
· Does the trainee cool the tool regularly?
· Does the trainee stick to the given dimensions?

- Flat chisel, cape chisel and scraper

· Does the trainee grind the cutting edge through regular to- and fro-movements?

· Does he cool the tool sufficiently?

· Does he comply with requirements for angularity and parallelism of the cutting edges with the outer edges?

- Drills

· Does the trainee apply the main cutting edge of the drill in a horizontal position and with a setting angle from the left of about 58 degrees?

· Does the trainee prese the drill upwards and to the right simultaneously?

· Did the trainee avoid typical grinding faults?