Have you ever seen Defiance?
A group of Jews were on the run from Nazis. They ran into the forest together and created a make-shift society to live in the woods, so far away from the fighting that they might actually survive. This group all decides to turn to communism together in order to survive. Everything they have ever owned is put into one central pot and they maintain through the winter and a few more years after being bombed in the forest by Nazis.
The premise is that unless they all worked together as such, the entire group would have died off.
It is loosely based on a true story.
In this case, Communism seemed to work really, really well. To your point, everyone was in and no one wanted to do something different. Furthermore, the concept of how to behave was really well understood among the group. Lastly, it was a rather small group that only reached the size of about 1500 people.
The Pythagorean Community worked well too until he died. It also was not a large group. I do think it can work in small communities if they are VOLUNTARY (aka not requiring force) but I don't see evidence that is scales very well.
Also I've watched all of Defiance... there was a lot of Free Market in that too, which is not really communist. :)