STM B, the lab's second UHV STM, had a very troublesome method for sample transfer It used an outside grasping claw that had no positive contact. Thus it was possible to drop the sample. This compound claw grabs an ID ring thus once engaged, cannot fall off. Additionally it uses shoulder screws in compound shear and simple strong parts throughout. Hopefully grad students will take a while to break it and be able to fix it easily when they do. All Stainless steel save for the little thrust washers which are wire EDM'ed 945 bronze .005 thick. Design was super simple, easy to machine and modify. All parts were electro-polished.
