V2: 

Removed the cross bars from the grate since those got in the way. Also angled the tops of each beam in the grate so that it encouraged the pellets to fall through quicker. Testing the two side by side this was a huge improvement. Also made the main body 6mm narrower since that was easier than changing the width of the beams.

V1:

Remade the grate so that pellet litter fits through without scaling the rest of the object. Like the original it shouldn't need supports.