Turning Lathes; A Manual for Technical Schools and Apprentices. a Guide to Turning, Screw-Cutting, Metal-Spinning. &C., &C
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1888 edition. Excerpt: ...them on it until they take a light straw colour, or deeper straw, beginning to verge into blue. Then drop again into cold water, and they will stand well upon most bars of rolled iron. The latter may itself cause broken and short shavings, owing to cracks and defects; but, after a little practice, it will soon be seen whether this or the tool is at fault. Never rest satisfied with bad work or hitching, chopping, scraping, or anything but an evidently clean cut. If not obtained, the grinding is faulty, or the tool badly placed. When both these conditions are correctly carried out, the tool cannot possibly fail to work well. After thoroughly getting hold of both the principle and practice, by the use of the normal tool, another simple form should be tried--e.g., one ground to 90deg. front angle and 45deg. top rake, which is exactly the graver used as a double-edged tool, instead of as a single-edged one, as it is when used by hand in the way already described. Then, taking the normal tool as a foundation, file away one edge almost to nothing, taking a great sweep out with a round file, and you have a tool for the side of a shoulder or an odd corner. File out both sides till you get a parting tool--and, in fact, see how many useful shapes you can obtain out of that one plain tool. You thus learn, step by step, the real value of the cutterbar system. Even workmen who have never heard of double edges, or who scorn to depart from their ancestral inheritance of rule of thumb, do unconsciously adopt the principle when they give more top rake to that side of a round-end tool that is leading. They set the tool "end on," at right angles to the Lathe bed, and then find it cute badly, unless the leading edge is higher than the other. It is a rule in...
- Paperback | 36 pages
- 189 x 246 x 2mm | 82g
- 27 Jun 2012
- Miami Fl, United States
- Illustrations, black and white