TA 101: Technical Arts II Dr. Prishati Raychowdhury Department of Civil Engineering IIT Kanpur Office: FB 330; Phone:

Review How to find True Angle between two planes? AHAH BHBH CHCH DHDH BFBF DFDF AFAF CFCF F H H A1 B A1 A A1 C A1 D A1 A1 A2 C A2 A A2, B A2 D A2 Ø TL EV ABD EV ABC True Angle will be available in a plane where both planes are in EV (and their common side is in PV) Steps: 1)Identify the common side 2)Obtain TL of common side 3)Obtain PV of common side and EV of the planes 4)Measure angle between EVs TRUE ANGLE

Review How to find True Angle between a line and a plane? F H AHAH BHBH CHCH DHDH TL H A1 BFBF B A1 DFDF AFAF EFEF E A1 A A1 A1 A2 C A2 A A2 D A3 B A2 E A2 TS C A1 D A1 EV abc CFCF A2 A3 TL de TRUE ANGLE A A3 B A3 C A3 E A3 D A2 Steps: 1)Get EV of plane ABC in A1 2)Project DE in A1 3)Get TS of plane ABC 4)Project line DE in A2 5)Get TL of line DE in A3 6)Get EV of plane ABC in A3 7)Measure the angle in A3 True Angle will be available in a plane where the plane is in EV and the line is in TL EHEH d1d1 d2d2 d3d3 d1d1 d2d2 d3d3 EV abc

Auxiliary View Lecture 20

Remember: Principal Orthographic Views F P H

Auxiliary Views Concept

H F F A1 F A2 Note: Partial information is given in Auxiliary Views

Auxiliary Views Concept Auxiliary views are used when – We need to show the true size and shape of a surface that is not parallel to one of the principal planes of projection – We need to draw the orthographic views of an object whose side is not parallel to principal planes of projection Theories employed from – Orthographic projection – Space geometry

Auxiliary Views Concept Primary Auxiliary View is the one which is taken from one of the principal planes of projection A primary auxiliary view can be one of the three types – Adjacent to Horizontal/Top view, – Adjacent to Frontal, or – Adjacent to Profile A secondary auxiliary view is the one which is taken from a primary auxiliary view. The principles of drawing a secondary auxiliary view are same as that for a primary auxiliary view

Auxiliary Box F H F A1

Construction of Auxiliary Views 1.Draw the principal views 2.Draw a hinge line (e.g. F-A1, H-A1, P-A1) 3.Draw the projectors into auxiliary view (A1) 4.Transfer the distances (as you did in space geometry) 5.Complete the auxiliary view (in A1 or A2)

Construction of Auxiliary Views A B CD A B C D A B A B C D TRUE SHAPE of ABCD A B C D D C Find True Shape of the oblique plane ABCD Oblique view of ABCD EV of plane ABCD Oblique view of ABCD F H F A1 P F

Construction of Auxiliary Views: Steps  In order to get the TS of an oblique surface in an auxiliary view, an EV of the oblique surface is needed  For this, a line in TL is needed which is common in the oblique surface and a principal orthographic plane  Once a line in TL is available in F, H, or P plane, its PV can be obtained and the oblique plane will then be in EV  Sometimes, a reference line (or plane) parallel to hinge line (or H plane) may be used (instead of the hinge line itself) to transfer distances and draw auxiliary views Which is the line in TL common to oblique plane and principal plane?

Simple Problem of Oblique Surface 1 H EV H F Normal View (True Shape) TL A B C D A B C D D,A B,C 1 2 A B C D Find the line in TL in HV common to oblique plane and principal plane?

Example 1 Consider the truncated pyramid, find Normal View of the oblique top surface 1)Identify the line on oblique surface which is in TL in top view 2)Draw hinge line perpendicular to the TL 3)Obtain EV of the oblique surface in Auxiliary plane R1 4)Note that a Reference Plane (R1’) is used instead of the hinge line H-F 5)Similarly, a Reference Plane (R2’) is used instead of the hinge line H-R1 6)True surface is obtained in plane R2 1 H H H H H H H H H H H' R2' H R1 R TL 12 H F Reference plane R1’ 1 R1, 2 R1 3 R1, 5 R1 4 EV d d True Surface d1

Auxiliary Views of Oblique Surface

Drawing a Machine part with an Oblique Surface

Construction of an Auxiliary View: Curved Surfaces Completed ‘Front’ and ‘Top’ views from auxiliary views. Note that this is a reverse process (of drawing an auxiliary view).

H F H A1 A2 AUXILIARY VIEW (A2) AUXILIARY VIEW (A1) F Example 2

Thank You