I am assembling a hole punch shown in the attached image. I want to create an animation where the cutter (part 6) goes down and then back up after a quick pause. I read the pdf document on Animating assemblies, it doesn't tell me how to simulate a back and forth motion. I can apply the motor on punch rod (part 3) in only one direction (counter clock wise direction) to simulate the part of cutter going down. I am not sure how to simulate the part where the cutter is coming back up to its original position. Do I have to add a second motor? If yes, how should I do it?
You do not need to add a second motor. In the animation timeline click on the current duration bar, right click on it and select Copy, then go to the righ of the duration bar and right click again and choose Mirror where you want the reversed motion to start.