|Grinding of Simple Tools - Course: Technique for manual working of materials. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 19 p.)|
|1. Purpose of grinding|
|2. Machines for grinding|
|3. Tools for grinding|
|4. Operation of grinding|
|5. Operation of whetting|
|6. Examples for off-hand sharpening with straight wheels|
|7. Hints for mounting and dressing of grinding wheels|
|8. Labour safety recommendations|
With mounting the grinding wheel, observe the following order:
- Sound out the grinding wheel if it has a ceramic bond (clear, slowly dying away sound - faultless wheel);
Figure 20 - Sounding out the grinding wheel
- If the bore hole is too big, put a lead bushing (2) into the wheel (1);
- Clamp the wheel (1) between two flanges of the same size (3);
Figure 21 - Clamping device of the grinding wheel
- Put soft, elastic washers of rubber or cardboard (4) between the wheel and the flanges;
- Fasten the wheel by a bolt washer (6) and a lock nut (5) on the shaft.
Pay attention that the right end of the shaft has a right-hand thread, the left end of the shaft a left-hand thread. Then. the spark killer has to be adjusted so that the maximum distance between the spark killer and the grinding wheel is approximately 5 mm. The grinding support must not be more than 1 - 2 mm away from the grinding wheel, because otherwise there is the risk of thin tools being drawn in.
Since the size of the grinding wheel is reduced by abrasion during the grinding process, the distances must be permanently put right.
After the grinding wheel is mounted it roust be dressed in order to guarantee that it runs true. Dressing becomes also necessary when the grinding wheel is uneven or sticky. Only cutting or grinding dressers are used:
- Manual dresser
- Dressing stick
Figure 22 - Manual dresser
Dressing diamonds are applied with the help of dressing devices, if very great demands are made on the grinding wheel as to the precision of dimensions and form as well as surface quality.
With running grinding wheel the manual dresser or dressing stick is pressed firmly against the grinding wheel and slowly moved to and fro.
Put on safety goggles and respirator - very strong formation of dust - very detrimental to health I