What Is The Asme-recommended Height For Dimension Numbers And Notes On Drawings?

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Engineering science Drawing Notes Part A – Coordinat eastward Dimensioning and Tolerancing PowerPoint Presentation

Engineering Drawing Notes Part A – Coordinat due east Dimensioning and Tolerancing

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Applied science Drawing Notes Part A – Coordinat due east Dimensioning and Tolerancing

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1. ME170 Computer Aided Blueprint Engineering Drawing Notes Part A – Coordinate Dimensioning and Tolerancing Instructor: Mike Philpott Emeritus Associate Professor of Mechanical & Industrial Technology

2. Engineering science Drawings - orthographic projections ANSI Drafting Standards – ASME Y14.5M ANSI/ISO Tolerance Designation ANSI/ISO Nomenclature of Limits and Fits Surface Backdrop Economics of Tolerances/Surface properties Geometric Dimensioning and Tolerancing (GD&T) Contents Attention to Detail The engineering drawing is the specification for the component or associates and is an important contractual certificate with many legal implications, every line and every comment is important.

3. Assembly Drawings: Assembly drawings are used to show the position and functional relationship of parts in an assembly, too via multiview orthographic projections. Generally they have no dimensions on them. Parts are 'balloon' identified and referenced to either detail drawing numbers or catalog numbers, via a Beak of Materials (BOM) Role and Assembly Drawings • Part Drawings: • Detail drawings completely draw a single part with multiview orthographic projections. • Should provide all the information necessary to economically manufacture a loftier quality role.

4. Top Rear Left Front Correct Bottom Title Cake Orthographic Views Preferred 3 views - grade Fifty shape Rear Peak Left Correct Front Lesser

5. The Drinking glass Box Concept

6. The glass box concept theorizes that an object is suspended inside a 6-sided glass cube (notice the utilise of hidden lines on the glass box, depicting lines that would not exist visible from the given perspective).

7. Every bit the object is viewed from a specific orientation (perpendicular to one of the sides of the cube) visual rays project from the object to the projection plane. These projectors are e'er parallel to each other.

8. The object'southward image is formed on the projection plane by the pierce points of the visual rays.

9. The process is repeated to construct the right side view on the profile airplane

10. Similarly, the top view is projected to the horizontal plane

11. For many three-dimensional objects, two to three orthographic views are sufficient to draw their geometry.

12. The box tin can exist unfolded to show the multiple views in a unmarried x-y plane

13. Because the observation point is located at infinity, the integrity of characteristic size and location are maintained, and the views are oriented orthogonally in human relationship to each other. TOP RIGHT SIDE FRONT

14. Observe that the projectors or extension lines, are perpendicular to the folding lines of the glass box. (Fold lines and extension lines are drawn very lightly, when used, and are not part of the finished cartoon.) TOP RIGHT SIDE Forepart

15. Final Views – 50 format, front end, correct, superlative are ANSI and ISO 'preferred' layout (and minimum views)

16. There are three distinct line weights to be aware of: object lines are thick (approximately .030-.040" thick), hidden lines are a medium thickness (.015-.020"), and extension, dimension, and centre lines are thin (.007-.010"). Dimensional Data can then be added to the cartoon

18. Complete the 3 view drawing (without dimensions for now). Brainstorm by projecting all of the known information betwixt the views.

19. Brainstorm past projecting all of the known information between the views.

20. Heavy-up all of the object lines that describe visible object lines, and evidence surfaces that would not be visible in the specific orientation, using dashed/subconscious lines.

21. Complete the right side view past projecting all of the relevant lines and points using a 45 degree miter line. Clean upward the drawing.

22. Remove the terminal structure lines to come across the finished drawing

26. 2. Coordinate Dimensioning and Tolerancing ANSI standard - ASME Y14.5M - 1994 The commonage procedure of modeling, defining and describing geometric sizes and feature relationships, and providing all of the required technical information necessary to produce and inspect the part is chosen dimensioning and tolerancing. The National Standard for dimensioning and tolerancing in the United States is ASME Y14.5M Drawn IN Accordance WITH ASME Y14.5M - 1994 REMOVE ALL BURRS AND SHARP EDGES ALL FILLETS AND ROUNDS R .06 UNLESS OTHERWISE SPECIFIED Geometric Dimensioning and Tolerancing (GD&T) : ASME Y14.5 - 2009

27. Dimensioning Scheme – deciding what, where, and how to add dimensions to the drawing twenty

28. Object Lines Hidden Lines Center Lines Phantom Lines Dimension Lines Extension Lines Leader Lines Cut Plane Line Sections - Hatching Break Lines Line Types thick thin thin thin thin thick thin thick

29. Arrowheads are used as terminators on dimension lines. The points of the arrowheads on leader lines and dimension lines must brand contact with the feature object line or extension lines which represent the feature existence dimensioned. The standard size ratio for all arrowheads on mechanical drawings is 3:ane (length to width). 200 R 8.5 Arrowheads Of the four different arrowhead types that are authorized by the national standard, ASME Y14.2M – 1994, a filled arrowhead is the highest preference. 4th 1st 2nd third

30. Dimensions should be placed outside the actual function outline. Dimensions should not exist placed within the part boundaries unless greater clarity would upshot. Dimension Lines and Extension Lines Extension lines overlap dimension lines (beyond the point of the arrowheads) by a distance of roughly 2-3mm ane.75 There should be a visible gap (~1.5 mm) between the object lines and the start of each extension line. 1.06

31. Placement of Linear DimensionsOrder of Preference Arrows in / dimension in 2.562 Arrows out / dimension in 1.250 Arrows in / dimension out .750 Arrows out / dimension out .500 When there is not enough room between the extension lines to arrange either the dimension value or the dimension lines they can exist placed outside the extension lines as shown in the fourth example (use Flip Arrows in ProE).

32. Reference dimensions are used on drawings to provide support data only. They are values that accept been derived from other dimensions and therefore should not be used for adding, production or inspection of parts. The use of reference dimensions on drawings should be minimized. Reference Dimensions Reference Dimension Symbol (X.Xxx) Case 2.250 (.750) 1.000 .500 .500 1.250 .500 (.750)

33. Dimensions should be placed outside the actual part outline Location of Dimensions Shorter (intermediate) dimensions are placed closest to the outline of the part, followed past dimensions of greater length. Dimensions nearest the object outline should be at least .375 inches (10 mm) abroad from the object, and succeeding parallel dimension lines should be at least .250 inches (6 mm) autonomously. .250 (6mm) Minimum Spacing four.375 one.438 1.250 .375 (10mm) Minimum Spacing 1.000 1.875 ane.062 .688 2.312

34. Basic Dimensioning – Proficient Practice 4.375 1.438 ane.250 one.000 ane.875 ane.062 .688 ii.312 Extension lines should not cantankerous dimension lines if avoidable In-line dimensions can share arrowheads with contiguous dimensions 1.250 one.438 1.000 ane.875 ane.062 .688 two.312 BETTER four.375

35. Diameter Dimensions Holes and cutouts one.375 .625 THRU .250 .62 .250 10 .62 DP i.375

36. Whenever information technology is practical to practise so, external diameters are dimensioned in rectangular (or longitudinal) views. Cylindrical holes, slotted holes, and cutouts that are irregular in shape would unremarkably be dimensioned in views where their true geometric shape is shown. .25 THRU 1.25 .75 2.00 Diameter Dimensions Shafts and Holes

37. Placement with Polar CoordinatesTo dimension features on a round or axisymmetric component 18º 18º 3X .562 3.50 6X .188 .875 18º 18º 18º 18º

38. Radial Dimensions To betoken the size of fillets, rounds, and radii R.312 R14.25 R.750 R.312 R.562

39. Angular Dimensions: To signal the size of angular details actualization as either athwart or linear dimensions. 92º ii x 2 or ii ten 45º 63º Alternating

40. The X symbol can also be used to indicate the word "past". For instance, when a slot that has a given width by a specified length, or a chamfer that has equal sides (.12 10 .12). When used to imply the word 'by',a space must precede and follow the X symbol. If the same feature is repeated on the drawing (such every bit viii holes of the same diameter and in a specified blueprint), the number of times the instruction applies is called out using the symbol X. 8X .250 THRU "Times" and "By" Symbol: X .12 X 45º CHAMFER .375 .562 10 82º CSK

41. Section views are used to clarify internal detail and to avert dimensioning to subconscious lines The are established past referencing a cutting aeroplane Cut planes depict the exact location on the part from which the department view will be projected, and should accept associated arrowheads, indicating the management from which the department view will be observed. Cutting planes are constructed equally an integral feature of the parent view, and cutting plane arrowheads always indicate the direction for the observer'southward line of sight. Section Views A A SECTION A - A

42. Alpha Characters A - A, B - B, C – C*, etc., are used to designate the required section view. The characters are placed well-nigh the arrowheads and equally a subtitle of the view. In that location is no "standard" for the location of the department designators, other than near the cutting plane arrowheads—as the examples below illustrate. When the alphabet has been exhausted, use double characters AA - AA, BB - BB, CC – CC*, etc. *Section Designators should NOT include the alpha characters I, O, or Q. Cut Plane A A Cut airplane on reference view SECTION A - A Subtitle of actual view

43. Crosshatching, is a repeating graphic pattern which is applied throughout all areas of the office that would be in contact with the cut plane. Thus, the hole is non crosshatched. The recommended bending for the standard crosshatch pattern is 45, 30, or 60 degrees with horizontal. Similarly, crosshatch lines should be neither parallel nor perpendicular to the outline of the feature in section—if avoidable (run into the examples beneath). Crosshatching Department Views Good Practice Poor Exercise Poor Practice

44. Cross Hatch Standards • The general purpose cross hatch is used in most individual item component drawings and in assembly applications where no confusion will result. • Each of the assembled components are depicted with a different crosshatch bending to assist in part differentiation. • Specific crosshatch symbols are sometimes used to represent each different material type.

45. Steel Magnesium, Aluminum Titanium Cantankerous Hatch Symbols Sand Cast Iron (General Utilize) White Metal (Zinc) Bronze, Brass, etc. Physical Felt, Leather, & Cobweb Marble, Slate, Glass, etc. Water, Liquids Wood; Cross Grain With Grain

46. Half section views are the effect of cutting planes existence positioned on parts in such a style that just half of the resulting view or projection is shown in section. Half sections are mostly used on objects of symmetry, individual cylindrical parts, or assemblies of parts. One-half Sections

47. Shown without section: Difficult to dimension without using hidden lines Internal features – not as clear One-half Sections

48. Offset sections allow u.s. to provide greater breadth of item with fewer section views. All of the features are aligned with the cutting airplane. D D Offset Sections Department D - D

49. Projected Section Views A SECTION A – A ROTATED 30º CLOCKWISE A

50. Drawing Notes Notes should be concise and specific. They should utilize appropriate technical linguistic communication, and be complete and accurate in every detail. They should be authored in such a way every bit to take merely one possible interpretation. General Notes Drawn IN Accord WITH ASME Y14.5M - 1994 REMOVE ALL BURRS AND SHARP EDGES ALL FILLETS AND ROUNDS R .06 UNLESS OTHERWISE SPECIFIED Local Notes 4X 8.20 M10 10 i.25 82º CSK x 1.5 X 45º CHAM

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