I am assisting a friend whose layout consists of under the table tortoise switch machines. He is not a train guy, this layout came with the house. Most of the turnouts permit a train to pass through if the train enters from one of the diverging routes and the switch is aligned against the train. This seems to be a function of the springeness (sp) of the throw arm. One turnout is very stiff, resulting in consistent derailments if not set correctly. I am guessing bending the throw arm may help but don't want to attempt this without some conformation. Can anyone with experience with these offer some suggestions?