[PhantomPhyxer]

Start off by weighing all parts and recording that weight in an Excel Spread Sheet.
For those parts that are designed in Cad set the the material density correctly and CAD will calulate the part. Insert that number in the Excel Spread Sheet. Where possible use Aluminum. Limit the number of bolts to what you actually need to prevent rotation or shear. If you have to drill holes to mount something then use those mounting holes to mount something else if possible. That will reduce the number of bolts. If you keep track of weight only in CAD then use lump masses for those things like electrical.

The weight spread sheet can also be used for cost of your Robot because you have to account for every part on the Robot.

Fortunatily programming code does not weigh any thing! (:-)