elbow drafting machine
I saw a drafting discussion here which is why I am here. Simple question. How do I determine the board coverage of an arm type based on scale length, arm length, arm swing, and clamping spot? I see arms in the 15 to 24 inch range, and scales from 12 to 18 inches long. There are very few that have any indication that coverage is less than typical. Such as "JR", MINI, SHORT or others. I need coverage no more than 24 x 24. Probably less. A vintage DIETZGEN 1930's with arms of 15 and 20 is clamped to its own board that can be closed and stored in a draw. A3 size? Formula would be nice or a simple chart. Thanks.