Model making; including workshop practice, design and construction of models, a practical treatise for the amateur and professional mechanic .. (1919)
Yates, Raymond F. (Raymond Francis), 1895- ed · New York, The Norman W. Henley Pub. Co. · leaf 72
be the first one drilled. It wouldbe very bad practice to start drilling this hole with a%-inch drill, as the web of such a drill is so broad thatit is a very difficult matter to accurately *center it.The only way to overcome this disadvantage is to startthe hole with a drill of smaller gauge—in… … Fig. 45—Showing the use of a **V-Block spindle down until the drill touches the center dot. Per-mit the drill to go just far enough to drill the dot off,then raise the spindle, and, by means of the small circlescratched on the plate, see if the tiny indentation made 70 Model Engineering is exactly…
Machinery
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