|Course: THEA 272 Stagecraft
Introduction to Mechanical Drawing
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|Drawing board*||Tracing paper*|
|T-square*||Pencils: .5mm H*, B; 3mm HB|
|Triangle: 45-45-90*||Eraser: Soft red*|
|Architect’s scale*||Variable triangle|
|Draftsman’s tape or dots*||French curve(s)|
|Erasing shield||Cleaning powder|
|Duster (draftsman’s brush or clean cloth)||Various leads in lead holders and pointer are also useful.|
-Light from the left (for right handers)
-Position paper on board with T-square. Tear 4 pieces of tape. Place one diagonally away from center of paper in upper left corner. Smooth paper diagonally with hand to lower right corner, align, and tape diagonally. Smooth away from center to upper right and tape, then to lower left.
-Wipe off and wash ruling instruments in mild detergent and warm water. Always work with clean hands. Never dust erasures with your hands!
-Plan your drawing to work from hardest pencil to softest, and to avoid passing instruments over final lines as much as possible. Suggestion:
-Keep T-square braced tightly against the left edge of the board by rightward pressure with the heel of the left hand. Triangles may be held in alignment tightly with fingers.
-Never use T-square against more than one edge of the board.
-Triangles can be combined to provide all angles at 15-degree intervals, or use variable triangle.
-Triangles can be used for a straightedge, but never rule with the scale!
-Accuracy of measurement is critical, especially in scale: Sight directly from above the scale to measure, mark the point with the pencil.
-Irregular curves: Locate several points along the curve and sketch through them, or use a French curve to rule them.
-Lay-in and guide lines: H with a light hand, or harder (2H or 4H).
-Dimension and extension, and other information lines: Firm H
-Construction and object shape lines: Firm B
-Lettering, arrowheads, leaders, underlining and boxing: Firm H, HB, or .3mm HB
-Use vertical or inclined Gothic (not cursive, consistent case).
-Use guidelines drawn in lightly, or use graph paper under tracing paper.
-Rest hand on T-square or paper to shield drawing.
-Lettering normally runs parallel to T-square, not at odd angles.
-Common lettering problems:
-The form for the dimension information is always x’-x"
-Extension lines should not touch the drawn object.
-Leaders should be freehand lines with at least one obvious wave or curve to distinguish it from other working lines.
-Arrowheads should be formed with a three-move stroke, carefully pointing to exact points, to clearly distinguish leaders and dimensions from working lines.
-Always place title blocks in the same place, usually lower right corner. Readers need to expect where they will find the information.
-The block must contain the following information:
-The block may also contain information on the producing organization, the plate number, previous revisions, etc.
-Several forms are acceptable, but clarity and easy access to information is most important.
-Notes about construction and procedures, legends, etc., should be collected in one area of the drawing plate as much as possible, and headed and/or boxed.
-Frequently, notes must be placed where a leader can indicate an area of the drawing for clarity.
-All views must be separately labeled, usually in all-caps and double-underlined.
-Place below or beside the view so there is no confusion of what is labeled.
-If more than one scale is used on the plate, such as a larger scale for a detail, the block will contain the dominant scale and views with other scales are labeled, or each view must be labeled for scale.
-Traditionally, the drawing always has a border. It confines the drawing and indicates whether the print is a complete plate.
-Many draftsmen also box "Notes," "Legend," "Materials," and other non-pictorial parts of the plate, as well as the title block.