Alright, I made it work 
 
 Firstly, I made the metric scale to meters in window/settings/preferences/preferences/settings. Then I removed your joints, scaled up the cubes by 100 to match the metric scale and freezed the transformation, then I made the 2 cubes into 1 polygroup instead of 2 by selecting them both and using  the "combine" tool. Then I selected the created polygroup of the 2 cubes and went to edit/delete all by type and then I clicked "non-deformer history". Then I re-made the joints and made a simple animation and it worked perfectly. 
Here's my maya file and the dae file so you can see 

 Hope I helped!