Week3 Enge 1114 Lecture

Week3 Enge 1114 Lecture - Exploration of Engineering Design...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Exploration of Engineering Design Join us in DyKnow ENGE1114_1119M_200801 Username: pid@vt.edu (your email address) Password : dyknow EngE 1114, Spring 2008 Engineering Education 1 Announcements Design Project Kickoff Thursday 1/31 McB 100 6:50-7:50pm - Students in Tuesday and Wednesday Workshops 7:50-8:50pm Students in Thursday and Friday Workshops Make arrangements to meet and sit with your team Engineering Education 2 Announcements Extracurricular Information on Common BB site Connection 2008 Coop and Internship Job Fair Request for your input The EngE Department Head Evaluation Committee requests your feedback in the evaluation of Dr. Hayden Griffin, Head Short (2 questions) Student survey link on Common BB site Available Jan 28-Feb 4 Thanks in advance for your feedback! Engineering Education 3 Visualization Isometric View Orthographic Multiview Primary Views Types of planes Reasons for lines Sketching Techniques (boxing in) Inventor Engineering Education 4 Projection Theory representing 3D objects in 2D space Classifications I. multiple views each showing only two of objects three dimensions single view with all three dimensions presented II. preserves true relationship of object's features more closely matches visual perception, more difficult to sketch Engineering Education 5 The Principle (Primary) Views and Dimensions The isometric pictorial is for reference and is not considered part of the multiview sketch. Engineering Education 6 Adjacent and Related Views Engineering Education 7 Line precedence determines which line should be drawn when lines for different features in a view coincide. 1 A. B. C. 2 Visible Hidden / Cutting Plane Center 3 Engineering Education 8 Sketching and Visualization For the given top and side view, sketch the isometric and front view for as many different objects as possible. Engineering Education 9 Dimensioning Engineering Education 10 Dimensioning Dimensioning conventions were developed in accordance with machining operations. Most dimensioning "rules" are guidelines. The only hard and fast rule is: You must include sufficient dimensions to completely describe the size and shape of your part. Anything less and the drawing is useless. The current version of the most common standard used in the US is Y14.5MANSI Y14.5M-1994 (R1999) 2.0 Engineering Education 11 Dimensions give information about the sizes and locations of features Guidelines for placement and orientation Guidelines are designed to promote: neater/cleaner drawings drawings that are not over/under dimensioned Summary on Bertoline pg 137 Engineering Education 12 Four line types are used in dimensioning Dimension Line Extension Line Leader Line Center Line Center Line Engineering Education 13 Dimensioning Engineering Education 14 Dimensioning circular features Dimension holes in the circular view Size positive cylinders in the rectangular view Dimension arcs >180o with , arcs <=180o with R Leaders on circular features should be radial. Engineering Education 15 Units are typically not specified unless they vary from the standard conventions English drawings; assume inches Metric drawings; assume millimeters Do not put units on your dimensions METRIC Engineering Education 16 Hole Notes depth Thru holes Engineering Education 17 Hole Notes Blind Hole In blind holes the specified depth is the depth at full diameter. Engineering Education 18 Reference Dimensions A numerical value enclosed in parentheses, providing information only and not directly used in the fabrication of the part. Alternately the radial value could be given as a reference dimension and the overall height specified, but then the overall width of the part, and the horizontal location of the center of the hole would also need to be given. Engineering Education 19 Chain, Datum, and Ordinate Dimensions 30 20 90 30 30 100 30 25 Ordinate Chain Datum or Baseline Engineering Engineering Education 20 Principles of Good Dimensioning Include sufficient dimensions Dimension each feature only once don't over dimension Dimension features in the most descriptive view Contour rule Don't dimension to hidden lines if at all possible Avoid dimensioning inside the object Dimension holes in the circular view, positive cylinders in the rectangular view Dimension arcs <= 180o with radius R, arcs > 180o with diameter (F) Extension lines should not touch object Extension lines should not cross dimension lines Engineering Education 21 ...
View Full Document

Ask a homework question - tutors are online