Maharashtra HSC Engineering Drawing (Technical Science) study guide
Maharashtra HSC Engineering Drawing (Technical Science) · Work through your exam, one topic at a time.
Engineering Drawing is one of the technical-science subjects in the Maharashtra State Board HSC vocational/technical stream, taken by students who intend to move into diploma or degree programmes in mechanical, civil, production or architectural fields, or straight into drafting and workshop roles. The paper is a pencil-and-instrument examination: you are assessed on the accuracy of constructions, the correctness of projection conventions and the neatness of finished sheets, not on recall alone. The Maharashtra HSC Engineering Drawing (Technical Science) study guide has 10 sections and about 3,670 words.
01Instruments, Standards, Lettering and Sheet Layout
A drawing board's working edge is the datum: the stock of the T-square slides along it and every horizontal is drawn with the blade. Set squares (45°–45°–90° and 30°–60°–90°) are used in pairs - one edge on the T-square blade, the other giving 30°, 45°, 60° and, combined, 15° and 75°.
364 words, about 2 min02Geometric Constructions and Plane Geometry
Bisecting a line, an arc and an angle; dropping and erecting perpendiculars, including at the end of a line by the semicircle method; dividing a line into any number of equal parts using an oblique line; and drawing parallels at a given distance. Regular polygons are built either by the general method - draw the circle, step off the side, erect a semicircle on the side and divide it into n equal parts, ray 2 giving the second vertex for every polygon - or by the dedicated pentagon, hexagon and octagon constructions.
393 words, about 2 min03Orthographic Projections of Points, Lines and Planes
In first-angle projection, the IS 10714 convention used in India, the object lies between the observer and the plane: the view on VP is the elevation and on HP the plan, with the plan appearing below the elevation when the planes are rotated open. A point above HP has its elevation above XY; a point in front of VP has its plan below XY.
402 words, about 2 min04Projection of Solids and Sections
Polyhedra (prisms, pyramids) and solids of revolution (cylinder, cone, sphere) are started with the axis perpendicular to one reference plane and the base parallel to the other. The standard resting positions are: on HP on its base; on HP on a base edge or corner; on HP on a generator (cylinder and cone); and freely suspended.
404 words, about 2 min05Development of Surfaces and Intersections
Parallel-line development suits prisms and cylinders: stretch the perimeter or circumference into a straight line and erect the true heights. Radial-line development suits pyramids and cones: obtain the true slant edge or slant height and lay true lengths along an arc.
356 words, about 2 min06Isometric and Oblique Projections
Isometric axes are 120° apart and drawn at 30° to the horizontal. Isometric projection foreshortens every axis to √(2/3) = 0.816 of true length, so an isometric scale marks 0.816 of each true length; isometric drawing uses full lengths along the axes and is the usual exam answer - same shape, larger size.
317 words, about 2 min07Machine Drawing: Orthographic and Sectional Views of Machine Parts
The front view is chosen to show the characteristic shape of the part; the plan goes below it and the side view beside it, aligned by projection lines, in first-angle. Hidden detail is dashed only where it is needed for clarity and is suppressed where it would clutter the drawing.
362 words, about 2 min08Fasteners, Threads, Keys, Couplings and Bearings
Thread forms: ISO metric 60°, BSW and BSF 55°, square, ACME 29°, buttress. Pitch is the axial distance between crests; lead = pitch × number of starts, so a double-start screw advances twice the pitch per turn.
366 words, about 2 min09Limits, Fits, Tolerances and Surface Finish Symbols
Basic size is the nominal dimension; the limits are the two permissible sizes and the tolerance is their difference (T = UL − LL). Deviation is the algebraic difference from basic size; the fundamental deviation nearest the zero line gives the fit letter - capitals for holes (H), lower case for shafts (h).
358 words, about 2 min10Building Drawing: Plans, Elevations and Sections
A building drawing contains the plan (view from above, cut about 1.2 m above floor level, showing walls, openings, fixtures and the line of section), the elevation (front view showing plinth, doors, windows, sunshades and parapet) and the section (vertical cut showing foundation, flooring, DPC, lintel and roof levels). Scales: 1:100 for plan and elevation, 1:50 or 1:25 for details, 1:200 for site plans.
348 words, about 2 min