(a) State two safety precautions to be observed when using the lathe
machine. 4. (a) Sketch the following scrapers:
(i) flat scraper;
(ii) half-round scraper;
- triangular scraper.
- State one use for each of the scrapers in (a).
- State three types of bonds used in making grinding wheels.
(a) This part of the question did not pose much problem to the candidates.
(b) The correct responses to (b(i), (b(ii) and (b(iii) respectively are:
(b(i)) - flat scraper – used for scrapping high spots on flat surfaces.
(b(ii)) - half-round scraper – used for removing high spots on cylindrical surfaces.
(b(iii)) - triangular scraper – used for removing burrs or sharp edges from the internal surfaces and other components.
(b) State one advantage and one disadvantage of using the following
metals for the construction of the frame of a lathe machine:
(i) cast iron;
(ii) mild steel.
(c) List three parts of the centre lathe.