Are you designing an enclosure for the Dominator 2x4?  
We recommend an interior opening of 46" deep by 65" wide by 44" tall.  This will allow for our 3Nm motor option to fit perfectly.  Adding a few extra inches to the width wouldn't hurt.

Are you designing an enclosure for the Dominator 4x4?  
We recommend an interior opening of 69" deep by 65" wide by 44" tall.  This will allow for our 3Nm motor option to fit perfectly.  Adding a few extra inches to the width wouldn't hurt.