Sketchpad Lab Make An Equatorial Sundial Face Plate

Transcription

1 Make n Equatorial Sundial Face Plate ate Per ssign# The following instructions will produce a faceplate for an Equatorial Sundial In a new sketch, construct ircle of a fairly large diameter. onstruct radius. Working your way from the outside in, construct concentric circles of decreasing radius. For each circle start at point and release the mouse over radius, so that the control point of each circle lies on radius. For ease of this exercise, rename your points if they disagree with the labels shown here. Using the segment tool, construct segment F, the portion of the radius of the largest circle which extends inward to the smallest circle. From the isplay Menu, select LINE WITH / THIK. ouble lick on Pt to mark it as a center of rotation. halo should swell temporarily around the point if you did this correctly. Select segment F, Point F and Point E. From the TRNSFORM menu select Rotate. click Fixed ngle, enter and then Rotate. Repeat this process until you have gone all the way around the circle. These are the hour lines for your sundial. Using the segment tool, construct segment E, a portion of the radius of the largest circle which extends inward to the second smallest circle. From the isplay Menu, select LINE WITH / THIN. With segment E and point E selected, select TRNSFORM / ROTTE and enter., then click ROTTE. With the rotated segment highlighted, select TRNSFORM / ROTTE again, but this time enter. Repeat the rotation at increments until you ve gone all the way around the circle. These are the half-hour marks. Using the segment tool, construct segment a portion of the radius between the rd and th smallest circles. Select Rotate. lick Fixed ngle, enter. and then Rotate. hange the Line thickness of the rotated segment to SHE. With the rotated segment highlighted, select TRNSFORM / ROTTE again, but this time enter.. Repeat the rotation at. increments until you ve gone all the way around the circle. These are the minute marks of your sundial.

2 Make n Equatorial Sundial Face Plate ate Per ssign# Using the segment tool, construct segment, the portion of the radius between the th and th circles. Select Rotate. lick Fixed ngle, enter. and then Rotate. hange the Line thickness of the rotated segment to THIN. Repeat the rotation more times until you have reached the first hour mark. These are the minute marks. Select the four minute mark segments which are visible. To reduce the amount of work required to finish the dial, you will rotate all four marks at the same time. From the TRNSFORM / ROTTE menu, enter, and rotate. Repeat the rotation at increments until you ve gone all the way around the circle Your final figure should look like this. There are three things more to do before you re finished. One is to label the hour marks, the second is to adjust the radii of the inner circles to suit your taste, and the third is to make the dial stand. To accommodate aylight Savings Time, we will begin at point F and change its label to (use the text tool). hoose a font style to suit your taste. ontinue clockwise around the circle to the next point. hange its label to. ontinue around the circle until you have labeled all the hour marks. Move these labels so they are inside the smallest circle. Remember that after the number comes the number! E

3 Make n Equatorial Sundial Face Plate ate Per ssign# uring Standard Time, clocks are not advanced an extra hour so our dial must be consistent with this. On the next bigger circle change the labels so that they are one hour less than the hour of the inner labels. You may wish to change the font style or size. Now you may wish to customize the appearance of your dial. y changing the radii using circle control points, or hiding the inner circles, you can produce a dial that is easier to read and a bit more interesting to look at.

4 Make n Equatorial Sundial Face Plate ate Per ssign# Finally, you will make the stand. Place a point on the largest circle directly opposite point and intersecting the o clock line. Select this point, point and radius and from the construct menu ONSTRUT PERPENIULR LINES. Place another point on the largest circle at the end of o clock line. Select this point and radius and from the onstruct menu, select, Parallel Line. Place a point at each intersection of these three lines. (two points total) eselect everything. Select the lines and from the isplay menu, select hide lines Finally, connect the two points on the circle with the two points just created, connect the two points with to each other with segments. Hide Radius and points and. efore printing be sure to SLE TO FIT PGE!

5 Make n Equatorial Sundial Face Plate ate Per ssign#