mechanical drawing. why do we draw? to communicate!!!

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  • Why do we draw?To communicate!!!

  • Why does it matter?Whats the use of a great idea if you cant convey it to any one else.

    No one is an expert at everything, so we must collaborate to reach a common goal.

  • Communication with Drawing(things to consider)Subject what you are trying to convey (Process, structure, function, material, etc.)

    Audience who you are communicating with(designer, client, manager, public, other engineers)

  • Types of Mechanical DrawingDrawing types we will explore todaySketchesIsometric DrawingsOrthographic Projections

  • When is a sketch useful?Think aboutWhat (subject)Who (audience)

  • Sketching look and feel

  • Sketching to show process

  • Sketching to explore form

  • DRAWING TOOLSruler or scalethick markerthinmarker30 60 90 triangledrafting dots or masking tape

  • Time to Draw!!!!!!!!Bring your markers and pencil and move to one of the large tables in Pappalardo

  • WARM UP (in marker, without erasers and rulers)connect the matching letters and symbols without lifting your marker, draw from your shoulders, not your wrist STAND UP to the side try drawing a few circles without lifting your markertry inscribing some circles in the squares youve just createdcan you make the circle touch the center of each side of the square? can you do it without lifting your pen?try inscribing ovals in the three orientations of diamonds created by two of your neighboring trianglescan you make the oval touch the center of each side of the diamond? can you do it without lifting your pen?

  • When is a technical drawing useful?

    Think aboutWhat (subject)Who (audience)

  • Technical Drawing - Isometric

  • Technical Drawing Orthographic

  • Technical Drawing Assembly section

  • Technical Drawing More Sections

  • Isometric Drawing

  • Isometric Drawing

  • Isometric Drawingfront corner is centered and verticalbottom edges slant up at a 30 degree angle from horizontal(You should be viewing 3 of the 6 faces of a cube)3030

  • ISOMETRIC DRAWINGheight (vertical) lines are always drawn vertically in at their true (or scaled) lengthwidth and depth (horizontal) lines are drawn 30 degrees from the horizontal at their true (or scaled) lengthall lines parallel to the height, width or depth are at their true (or scaled) lengthlines not parallel to these axes are not drawn at their true length


  • Isometric Drawing - Dimensions

  • Isometric Drawing - DimensionsIdentify line to dimension

  • Isometric Drawing - DimensionsDraw extension lines

  • Isometric Drawing - DimensionsDraw dimension lines

  • Isometric Drawing - Dimensionsdraw as many dimensions as you would need to make the part (no more no less)

  • DRAWING TOOLSruler or scalethick markerthinmarker30 60 90 triangledrafting dots or masking tape

  • Time to draw!!!!!!Take all your drawing tools and move to the tables in pappalardo.

  • ISOMETRIC PRACTICEdraw a 8cm cube (use pencil and a ruler at first)1 draw a single vertical (centered, starting at the bottom)2 draw the depth and width of the cube from the bottom of the vertical (30 degrees to the horizontal)3 draw the other two verticals4 draw the top of the cube

    trace over your cube freehand with your thin marker

  • ISOMETRIC PRACTICE 3D Ldraw a rectangular prism (use pencil and a ruler at first)1 use any height, width and depth same steps as the cube2 lightly trace the hidden lines of the bottom plane3 draw the L on the bottom and top plane, with the negative space closest to you4 fill in the remaining verticals5 erase extra lines

    trace over your lines with the thin marker, then trace around the outermost edges of your shape with the thick marker

  • ISOMETRIC PRACTICE - CIRCLEinscribe circles on each face of the cube1 in pencil, lightly divide each face into four equal sections by connecting the opposite edge midpoints2 (in marker) draw arcs in each of the four sections, connecting the midpoints of each edge and creating three inscribed circles

  • ISOMETRIC PRACTICE more complex objectsdraw one of the shapes in pencil at 1:2 scaleyou will need to measure the shapepick the appropriate orientation the one that gives the most detail about the object and its featuresstart with a cuberemember vertical lines, or lines in horizontal planes should be drawn first, then other lines (which may not be true length) can be drawn last to connect appropriate edges

    trace over your object with your thin marker, then trace around the outermost edges of your object with the thick marker

  • did anyone have an object that couldnt be fully expressed with a single isometric drawing?

  • ORTHOGRAPHIC PROJECTIONIsometric DrawingOrthographic Projection








  • ORTHOGRAPHIC DRAWING PLANNING what is the minimum number of views required to capture every object feature? often the answer is three, but it could be less or more!what is the best way to lay out these drawings best use of paper, should drawings be scaled up or down?we will be dimensioning drawings, so leave enough space around each view to add dimensionsthink about the order of inking to avoid smudging

  • ORTHOGRAPHIC DRAWING LINEWEIGHTS AND STYLESthick continuous line used for visible edges and outlines

    thin continuous line hatching, short center lines, dimensions or projection lines

    thin dash-dot line center lines, to identify the center of a circle or a line of symmetry

    thin dashed line used for important hidden detail, such a hole in a solid or a wall thickness

  • ORTHOGRAPHIC DRAWING DIMENSIONINGdraw as many dimensions as you would need to make the part, no more, no lessdo not add redundant dimensions, will lead to conflicts with tolerances if you can deduce a dimension from other displayed dimensions, it is redundantoften better to continually measure from one point than measuring from one point to another

  • ORTHOGRAPHIC DRAWING DIMENSIONING CIRCLES AND RADIIdimensioning circles all dimensions proceeded by note use of center linestwo projected lines from a diameter (least used)internally along the diameter, labeled internally or externally, depending on sizeif circle is very small, can dimension from outside the circle using an arrow which points towards the center

    dimensioning radii all dimensions proceeded by R should only have one arrowhead, and arrow should pass through circle centercan locate the center of the circle with center lines and an arrow with the measurement outside the circlecan dimension with an arrow originating from the center without center lines, label at center of circle

  • ORTHOGRAPHIC DRAWING PAGE LAYOUTall of your drawings should include:title of partyour namedate of drawingversion (if a previous drawing of the part exists)scale (dimensions will always be represented as if the drawing is 1:1, actual size)1:1 actual size2:1 drawing is twice as big as object1:2 drawing is half as big as objecta few words about dimensions all measurements are in mm well do thisall measurements are in inchesthese should be written neatly on the drawing sheet, each item is usually surrounded by a thin box, and the items are generally adjacent like a table

  • Time to DrawTake all your drawing materials and move back to Pappalardo.

  • ORTHOGRAPHIC PRACTICEtry drawing your 3D L with the orthographic technique

  • ORTHOGRAPHIC PRACTICEtry drawing one of the ten objects with the orthographic techniquewill need to measure the objectcan use ruler and pencil at firsttrace over lines with appropriate markerwrite scale and other page layout items on your drawingdont forget to dimension your drawing!

  • HOMEWORK due Mondaydraw something from your life at WTP, later youll model it in SolidWorks and create the isometric and orthographic drawings from the 3D model use traceisometricorthographic with dimensions and proper layoutexamples from other yearsphones, cameras, challenge: try drawing an object or two using only your thin and thick pens, without a ruler, pencil, straightedge or triangle see how close to isometric you can get freehand in your design notebook

  • ORTHOGRAPHIC DRAWING DIMENSIONING HOLESuse the skills from dimensioning everything elsediameter symbolas many views as required to fully understand holecenter lines and symmetry lines

  • ORTHOGRAPHIC SECTIONSoften interior features can not be fully described by isometric and orthographic drawings rather than struggling with hidden lines, a section may be more easy to create and more easy to understandimagine slicing the object along a planedont forget line weights and centerlineshatch material that is touching the slice planelabel orthographic drawing A-A (or B-B) to show where the slice was takenorthographic sections are much more common than isometric sections

  • How do I bring this to the classroom??????Use sketching for general design, planning and idea sharingLook and feelForm processUse technical drawing for final details such as assembly or part drawings for fabricationIsometricOrthographicAssembly

    *Picture is worth a 1000 words!!!words are pretty effective for some situations, often in Engineering and design, pictures are much more effectiveImportance of com


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