CE/ME 111 Engineering Design Graphics

1 CE 111 engineering Design Graphics Geometric Constructions Handout (GCH) Computer Constructions (DR-5) Although MicroStation is equipped with a rich selection of built in geometric objects and construction tools, you will use the geometric construction techniques illustrated in the Geometric Constructions Handout to complete the drawings in this exercise. The MicroStation tools you are allowed to use are only those, which emulate the function of a traditional drafting instrument or technique. These tools are as follows: MicroStation Tool Analogous Drafting Instrument Place Line Pencil and Straight Edge Place Arc by Center Compass, Dividers Place Circle by Center Compass Place Point or Stream Curve French Curve, Adjustable Curve Length, Radius, Angle Options Scale, Triangles, Protractor, Compass Axis Lock T-Square, Triangles Grid Lock Scale, T-Square, Triangles Snap Lock & Any Snap Mode T-Square, Triangles, Eyeball Mirror Tracing Paper Delete, Trim, Extend, etc.

2 Eraser Shield You will use the following seed files to complete this exercise: , , , , , and Change the (DR. BY) drawn by to your name and change the (DATE) before printing each drawing. You will use these seed files to practice proper construction techniques using only the tools listed above in MicroStation to simulate conventional mechanical drawing equipment. Refer to the Geometric Constructions Handout for help in completing each exercise. When printing your drawings show all constructions required to complete each drawing. DR-5-1, Constructing Lines Tangent to two Circles Using tangent snap draw a line tangent to the bottom of the two circles shown in dr-5-1sd. Then snap to the endpoint of each tangent point using keypoint snap and draw a line to the center of each circle using center snap.

3 Change the linestyle to dimension and use the dimension angle tool to display the angle formed by each tangent line and the line drawn to the center of each circle. The angle displayed should be 90 indicating that the line is tangent to the circle and is drawn properly. You are essentially repeating what has been done on the topside of the two circles. DR-5-2, Constructing an Arc Tangent to two lines drawn at a Right Angle Draw an arc tangent to the two lines shown in dr-5-2sd. Follow the procedure shown in the Geometric Constructions Handout. The radius of the arc to be drawn is 4 . Label the center of the arc using the letter C and the two tangent points A and B . DR-5-3, Constructing an Arc Tangent to two lines drawn at an Acute Angle Draw an arc tangent to the two lines shown in dr-5-3sd.

4 Follow the procedure shown in the Geometric Constructions Handout. The radius of the arc to be drawn is . Label the center of the arc using the letter C and the two tangent points A and B . Please note that the same procedure is used for two lines forming an obtuse angle. DR-5-4, Constructing an Arc Tangent to a Line and Another Arc that cannot intersect Using the method illustrated in the Geometric Constructions Handout, construct an arc tangent to the line and arc in dr-5-4sd. The radius of the desired arc will be 2 . The radius of the existing arc is . Label the center of the arc using the letter C and the two tangent points T1 and T2 . DR-5-5, Drawing an Arc Tangent to Two Arcs that Cannot Intersect Construct a radius arc, tangent to and to the right of the two circles shown in dr-5-5sd.

5 Use the procedure demonstrated in the Geometric Constructions Handout. Label the center of the arc using the letter P and the two tangent points T1 and T2 . DR-5-6, Construction of an Arc Tangent to given Arcs (Special Case) Using the method illustrated in the Geometric Construction Handout, construct a concave downward 5 radius arc tangent to the two given arcs. Label the center of the arc using the letter P and the two tangent points T1 and T2 . DR-5-7, Constructing an Inscribed Hexagon Draw a construction circle with diameter = 5 located at the intersection of the two lines shown in the seed file dr-5-7sd. Draw two more construction circles with diameter = 5 snapped to the intersection of the previously drawn circle with the line drawn along the x-axis.

6 Use intersection snap to define the location of the center of the two circles. The points of intersection formed by these constructions define each vertex of the hexagon. Use the place line tool and intersection snap to draw the inscribed hexagon.