ENME 414 Computer Aided Design, Fall 1997

Homework Assignment 4, Due 9 am, Friday, October 17

1. Tolerances can be specified in three formats, depending on their natures (page 52). They are unilateral format, bilateral format, and limit format. For each of the tolerances listed below, write the other two formats if these formats exist.

2. Use the tables provided on pages 59-73 to identify
   1. the maximum and minimum dimensions of the hole and/or shaft;
   2. the tolerances for the hole and the shaft, respectively; and
   3. the maximum clearance and the minimum clearance.
   (1) basic diameter: 5 inches, Basic-Hole System, Clearance Fit = LC2.
   (2) basic diameter: 5 inches, Basic-Hole System, Interference Fit = LN3.
   (3) basic diameter: 5 inches, Basic-Hole System, Transition Fit = LT3.
   (4) Draw a comparison diagram which includes the above three cases.
   

   
   

3. Use the tables provided on pages 59-73 to identify
   1. the maximum and minimum dimensions of the hole and/or shaft;
   2. the tolerances for the hole and the shaft, respectively; and
   3. the maximum clearance and the minimum clearance.
   (1) basic diameter: 5 inches, Basic-Shaft System, Clearance Fit = SLIDING.
   (2) basic diameter: 5 inches, Basic-Shaft System, Interference Fit = FORCE.
   (3) basic diameter: 5 inches, Basic-Shaft System, Transition Fit = LOCAT. TRANS.
   (4) Draw a comparison diagram which includes the above three cases.
   

   
   

4. The maximum and minimum dimensions of a shaft are 20.18 and 19.82, respectively. The maximum and minimum dimensions of a hole are 20.24 and 20.00, respectively. Use the statistical method to construct a normal distribution figure characterizing the variation of the clearance after the assembly.

   
   

5. A senior engineering is reviewing the tolerance information specified by a young engineer who just graduated from college. The tolerance value is 0.24 mm for the diameter of a hole on a component. The senior engineer knows that the smallest standard deviation among the lathes available in the company is 0.06 mm. There are 10,000 pieces of the hole components to be made. He is trying to tell the young engineer how may pieces of the hole component would be defective if the tolerance is kept at 0.24 mm. You are asked to make the calculation. How accurate is your calculation?