MGC 110. Dimensioning. Afr: Maatskrywing

Transcription

1 MGC 110 Dimensioning Afr: Maatskrywing Accuracy (correct values) Clearness (placed at appropriate positions) Completeness (fully defined, but no duplications) Readability (correct line quality) Afr: Akkuraatheid Duidelikheid Volledigheid Leesbaarheid

2 Arrow heads Pylpunte Correct

3 Dimensions Dimensies Why is this only a reference? Hoekom is die slegs n verwysing?

4 Lettering Skryf van Letters Capitals (except when writing units which are indicated with small caps example: mm) Block lettering At least 3mm high on final drawing or plot Hoofletters (behalwe as eenhede gebruik word wat met kleinletters aangedui word bv. mm) Blok letters Ten minste 3mm hoog op finale tekening

5 Extension lines Dimensions begin 1.5 mm from the object and extend 3 mm from the last dimension line Arrows: approximately 3 mm long and 1 mm wide Dimension lines: Afr: Verlengingslyne Afr: Pylpunte Afr: Dimensie lyne solid with the value placed above the dimension line. first dimension line is spaced 10 mm from the view REMEMBER: p 24 Correct

6 Reading Direction Dimensions should be oriented to be read from left to right, or bottom to top p 25 REMEMBER: Correct

7 Where possible, do not place any dimension inside an object REMEMBER: Correct

8 Dimensioning Small Features p 25 REMEMBER: Correct

9 Dimensioning Circles p 29 Diameters are dimensioned with a numerical value preceded by the diameter symbol, Φ Leader lines should be radial (ie. go through the centre point of the arc) Small Circles: REMEMBER: Correct

10 Dimensioning Circles p 29 WRONG REMEMBER: Correct

11 Dimensioning Concentric Circles p 29 Concentric circles should be dimensioned in a longitudinal view whenever possible Maximum of two diameters on Concentric Circles

12 Dimensioning Concentric Circles p 29 Concentric circles should be dimensioned in a longitudinal view whenever possible Maximum of two diameters on Concentric Circles Fully Defined?

13 Dimensioning Concentric Circles p 29 Concentric circles should be dimensioned in a longitudinal view whenever possible Maximum of two diameters on Concentric Circles REMEMBER: Correct

14 Dimensioning Radii (p 30) Radii are dimensioned with a numerical value preceded by the radius symbol, R Leader lines should be radial (ie. go through the centre point of the arc) REMEMBER: Correct

15 Centres of Circles p 30 REMEMBER: Correct

16 Centres of Circles p 33

17 Placement of Dimensions p 28 How can the placement be improved?

18 Placement of Dimensions p 28 Unnecessary Align Dimensions REMEMBER: Correct

19 Placement of Dimensions p 28 How can the placement be improved? REMEMBER: Correct

20 Placement of Dimensions p 28 Do not dimension to Hidden Detail REMEMBER: Correct Place outside view

21 Placement of Dimensions p 27 CORRECT

22 p 27 CORRECT

23 p 27 Never have a dimension line where it is crossed by a line or another dimension line. Crossed dimension lines should be avoided. Extension lines are placed so they do not cross dimension lines REMEMBER: Correct

24 p 27 Dimensions should be placed outside the boundaries of an object whenever possible WRONG!!

25 p 27 Extension lines begin 1.5 mm from the feature being dimensioned WRONG!! WRONG!!

26 p 27 Never have a dimension line as a continuation of a line of a view WRONG!!

27 p 34 Each feature of an object is dimensioned once and only once

28 Profile Dimensioning p 33 What is wrong?

29 Profile Dimensioning p 33 Dimensions should be placed in the most descriptive view

30 p 36! REMEMBER: NO DIMENSIONS ON HIDDEN DETAIL See Page 36 for a summary of dimensioning Principles.

31 Projection Symbol BOOYSEN GD M G1-P2 8/2/2006 M Mechanical N Metallurgical P - Mining C Chemical B - Industrial Text All Text are written using CAPITAL LETTERS in PEN

32 Complete in class and peers assess

33

34 Huiswerkoefening