[Solved in IRC] Damping in love.physics / Box2D

[timmeh42]

In a prototype I'm making, a space rock is constructed of 3 bodies (fixed to square shapes of density 1) in a row, each welded (using a weld joint) to the one next to it (ie 2 weld joints in total for the 3 bodies). The 'space rock' is set spinning around the middle body's centre by applying a force to the leftmost and right most bodies in opposite directions (perpendicular to the long axis of the 'rock'), and, it being in space, is meant to spin forever.

For each of the three bodies, both linear and angular damping are set to 0 - however, the 'space rock' still slows its rate of spinning very quickly at high speeds.
Therefore:

Is there any implicit damping by default in love.physics / Box2D? On the other hand, have I misunderstood all the factors that go into this?

As well as the damping, when a constant force is acting on each end of the 'space rock', it seems to reach a maximum rate of spinning based on the magnitude of the force - should it not be able to reach an infinite rate of spin?


(main.lua has been uploaded to demonstrate - left arrow key activates the force on the red lbock, right arrow for the blue block, hold both to spin the space rock.)

[Edit for clarification]