# How can a piece of steel rotated without any power input? [closed]

Currently I am trying to rotate a piece of steel >90 degrees without any power input. The piece of steel is attached on the wall. A servo is also attached on the steel.

This question addresses turning the piece of steel if the servo fails to work. A battery is not supposed to be used. Generally like a servo may do it with power the rotation should be performed without power whilst in this case the rotation has to take place only once. The trigger is a toggle switch that will drop,if pushed, a weight on the right side (see picture) in order to rotate the piece of steel. This rotation has only to be performed once. Doing this currently the required rotation >90 degree does not take place.

The remaining questions are:

1. Where has the weight to tip the steel ideally so that the piece of steel can be moved/rotated with the least amount of force? I was thinking that the edge of on the right side of the steel would be most beneficial location to tip with the weight. Am I right?
2. What weight must ‘the object’ be in order to move a 8cm x 2cm x 4cm piece of steel >90 degrees. Hereby I have to know the required force on the steel in order to rotate it.

Do I think too naively and have any mistake on my thoughts?

• are you allowed to use gravity as a power source? – ratchet freak Sep 23 '15 at 16:42
• @ratchet freak yes I am – Sathees Sep 23 '15 at 16:43
• Is there some sort of input mechanism to tell the piece when to rotate (a button or something)? When should it rotate? – Wasabi Sep 23 '15 at 17:04
• The trigger is not determined yet..so therefore free to design...I was thinking of a button as well. As long as it may work without any power a button can be utilized – Sathees Sep 23 '15 at 17:07
• I'm putting this on hold as it essentially asks us to design your solution for you. I suggest you narrow the scope of the question once you have identified a potential design either on your own or through other means such as our chatroom. For example, determining the weight you would need to tip the steel with a certain type of movement would be on-topic, provided you could show the design and point to a variable in it you needed to determine. – Trevor Archibald Sep 23 '15 at 19:24