[Ether]

Originally Posted by r691175002

Robot must carry ~15LB between two waypoints several kilometers apart without GPS. Terrain is generic grass/rocks/dirt/sand whatever is in the way.

Are you saying you want the robot to travel several kilometers over rocks and sand autonomously, with nothing but dead reckoning to keep it on track?

I don't consider brushed motors an option. For example, this 3000W motor from NPC:
http://www.npcrobotics.com/products/...at=20&mode=gfx
weighs 15 pounds. A brushless motor of the same power would weigh around a pound.

With a similar torque vs speed curve? Can you post a link please...

I'd like to avoid ackerman steering because some of the manoeuvres will need to be precise but it depends on what the software guys want. Crab drive/meccanum wheels and skid steering are also all on the table.

You're not going to get precise maneuvers on rocks and sand with mecanum wheels.