Section 66: Another Method for Gores to a Domed Head

Required Information

Draw a quarter circle in the bottom right area using the radius of the tank Divide the bottom right quarter circle into 12 equal parts and from these points set a straight edge that intersects the Apex to points on the small quarter circle.

Step 1
Draw a horizontal line the exact length of the radius of the tank and the rise combined. Draw a 90 degree vertical line the exact length of the radius of the tank and rise combined. The two lines intersect as shown in the drawing
Step 2
Draw a quarter circle in the top left area using the rise as the radius. Draw a quarter circle in the bottom right area using the radius of the tank
Step 3
Divide the bottom right quarter circle into 12 equal parts and from these points set a straight edge that intersects the Apex to points on the small quarter circle. Mark all 11 points on the small quarter circle
Step 4
Draw 90 degree vertical lines up from every point on the large quarter circle as shown
Step 5
Draw 90 degree horizontal lines from every point of the small quarter circle as shown
Step 6
Label all points on both quarter circles as shown
Step 7
Where Lines 2 intersect, mark with a dot. Do the same for Lines 3 -12
Step 8
Connect all the dots to form the tank top curve
Step 9
Determine the gore width by the trial and error method, then draw half the gore width on vertical line 12 and from that point draw a line to the Apex
Step 10
Add a 1/2" bead and ccccrimp allowance to the initial horizontal line. Draw the Stretch-out in the regular way