This probably depends on a lot of things, but the thickest my Landroid L 2000 has been able to cut, was about a centimeter in diameter. That's roughly 100 mickeys, 4.5 potrzebies or 2/5 of an inch, for those of you preferring imperial units. It's... A lot. Far more than I expected. But generally speaking, you shouldn't expect a robot to do more than what a weed whacker can do. Cutting thick wooden things will have a detrimental effect on your robot's blades really quickly!