Question

You are designing a ping pong ball launcher using 1 1/2 " pvc pipe as a launch tube. The diameter of a professional grade ping pong ball is 40+/- 0.5 mm. Schedule 40 pvc pipe actually has an inside nominal diameter of 1.610 inches. Using the convention: X is +/- 1 inch XX is +/-01 inch and XxX is +/-005 inches, what is the minimum clearance we should have between the ping pong ball and the inside of the pvc pipe in mm?

Answer 1

max dia of ping pong ball=40.5 mm

Min dia of ping pong ball = 39.5 mm

nominal inside diameter of PVC pipe for X =(1.610-0.1)*2.54*10= 38.354 mm

nominal inside diameter of PVC pipe for XX =(1.610-0.01)*2.54*10= 40.64 mm

minimum clearance between ball and pipe is = 40.64-40.5 mm= 0.14 mm