Us old school types rely on Magnetraction to perform the job. It's simplicity is only outweighed by the handy object sensor feature. When a metallic object is captured, nine times out of ten the engine comes to a violent hault. And nine times out of ten it stops somewhere totally inaccessible. 
Nice craftsmanship, Pat. I may have resort to one of these contraptions once my last Magnetraction engine gets destroyed.
Bruce
