Is it possible to weigh your robot within inventor if I specify the materials? thanks.
You can right-click on on the part in the browser window and go to iProperties, then go to physical. This will give you the mass, area, volume, and density. I don’t know if you can do the same in the assembly for the whole robot, but this works with the part. Hope this helps.
I want to say, but the best answer is sort of.
You can do this with a part file. It will tell you how much the part weighs. Then you would have to add up the weight of the parts to get the weight of the assembly. It would be terrible for like fifty parts, but if you think about it you can condense parts that are made of the same material into one file. I can’t remember the exact command to use this tool but I’m pretty sure it is under something like ‘properties’. Just read through the tabs and the drop downs and you should be able to find it.
Warning: This isn’t 100% accurate. I would calculate a 5% error. This is due to the fasteners to hold the parts together and other imperfections within the metal and other such problems.
Edit: Looks like GreerD beat me to the punch, but I’ll leave this due to some additional information. PM me if you want more details on how to make the most of this command.
Ok, thanks guys for the help.
Inventor can’t do mass properties?
Being used to NX, where you just highlight the solid bodies in an assembley and choose “advanced mass properties” from the dropdown menu, this is going to make my life difficult.
That really isn’t a hard feature to implement, either. If you can calculate the mass of a part, how much harder is it to code in a feature to be able to select solid bodies in an assembley to weigh?
Don’t make suggestions. They already have way too many features that really slow down computers. 
Way too many features? Is there such a thing?
The idea is solid for production purposes such as making a new part specific to your robot. The problem with using mass/weight for a large assembly item such as this is that each part you incorporate into your system (electronics, wires, wheels, batteries, ect.) might not already have these statistics associated with them. If you wish to go in and add/check the weight of each individual piece you use, then have fun but there is a time limit. As I’ve said many times before, the inventor award is won by a balance of scheduling and details. You can put all the details into your robot as you want, but at the end of the season a finished product better be submitted.