Lesson plan
drafting machine
A drafting machine (also drafting arm) is a tool used in technical drawing, consisting of a pair of scales mounted to form a right angle on an articulated protractor head that allows an angular rotation. The protractor head (two scales and protractor mechanism) is able to move freely across the surface of the drawing board, sliding on two guides directly or indirectly anchored to the drawing board. These guides, which act separately, ensure the movement of the set in the horizontal or vertical direction of the drawing board, and can be locked independently of each other. , a precursor to drafting machines , 1963. The drafting machine was invented by Charles H. Little in 1901 (U.S. Patent No. 1,081,758), and he founded the Universal Drafting Machine Company in Cleveland, Ohio, to manufacture and sell the instrument. Drafting machines were present in the design offices of European companies since the 1920s. The Encyclopædia Britannica explicitly specifies 1930 as the year this tool was introduced, but an advertisement of "Memorie di architettura pratica" from 1913 places it twenty years before this date—at least in Italy. In the older design sets, the movement of the protractor head was assured by a pantograph system that could keep the head in the same angular position throughout its range of motion. The arms were balanced by a system of counterweights or springs.…
Article summary
A drafting machine (also drafting arm) is a tool used in technical drawing, consisting of a pair of scales mounted to form a right angle on an articulated protractor head that allows an angular rotation. The protractor head (two scales and protractor mechanism) is able to move freely across the surface of the drawing board, sliding on two guides directly or indirectly anchored to the drawing board. These guides, which act separately, ensure the movement of the set in the horizontal or vertical direction of the drawing board, and can be locked independently of each other. , a precursor to drafting machines , 1963. The drafting machine was invented by Charles H. Little in 1901 (U.S. Patent No. 1,081,758), and he founded the Universal Drafting Machine Company in Cleveland, Ohio, to manufacture and sell the instrument. Drafting machines were present in the design offices of European companies since the 1920s. The Encyclopædia Britannica explicitly specifies 1930 as the year this tool was introduced, but an advertisement of "Memorie di architettura pratica" from 1913 places it twenty years before this date—at least in Italy. In the older design sets, the movement of the protractor head was assured by a pantograph system that could keep the head in the same angular position throughout its range of motion. The arms were balanced by a system of counterweights or springs.…
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
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Key claims and bibliography are generated from the same tracked claims and sources as the article page.