Whenever I use massless it acts weird. Let's say that I have two parts with different mass and they are in the air. I weld the larger one to the smaller one and set the massless property true for the larger one. When I run the game two parts fall as expected (the one with the massless = true doesn't contribute to the total mass), but when the smaller one hits the ground (massless = false) it acts very weirdly. It floats, moves slowly and after some time it stops and it's at an angle to the ground. It's difficult to explain if you've never worked with the massless property, you can try it if you want to. I need someone who has experience with the massless property. I know you probably don't understand me, but that's the best I can explain.

Anonymous