Lifting a mass from a point that is offset from its center of gravity

[Big Tommy C]

TL;DR

Does lifting an object from a point offset from is center of gravity incense force required to lift said object. Does torque that is countered add force required to lift a load?

Good Evening Everyone.

I am having trouble wrapping my head around the physics involved with the example below.
At first i was looking at this as if lifting may create a lever of some sort, but I don't believe it has a fulcrum.
I am trying to find a formula (if there is one) for lifting a mass from a point offset the the center of mass.
Does the force to lift a mass increase with the distance of an offset lifting point such as this in the example below?
I know the offset force will create a torque, assuming the mass is captive in a track of sorts, in this case a roller guide, would it be safe to assume the torque is cancelled out and wont add to the force required to lift this mass?
This is with the assumption that the roller create negligible friction in this example.

 

[Baluncore]

Mark the centre of mass on your diagram.
Extend the axis of the force being applied, until it passes the centre of mass.

The torque on the load, due to the offset, will have an arm length equal to the shortest distance between the CofM and the extended axis of the applied force.

You must counter that torque, with say, guide rollers and a vertical rail, in order to avoid increasing the load on the cylinder.

 

[jack action]

I know the offset force will create a torque, assuming the mass is captive in a track of sorts, in this case a roller guide,

The offset will create a torque even if there are no roller guides. In such a case, the part will accelerate (rotation-wise).

would it be safe to assume the torque is cancelled out and wont add to the force required to lift this mass?

If some outside torque balances out the torque due to the offset (ex.: coming from roller guides), the mass doesn't accelerate (rotation-wise).

Does the force to lift a mass increase with the distance of an offset lifting point such as this in the example below?

No. (Assuming friction is negligible and that nothing locks up, i.e. everything stays perfectly straight.)

 

[jrmichler]

TL;DR Summary: Does lifting an object from a point offset from is center of gravity incense force required to lift said object. Does torque that is countered add force required to lift a load?

I am having trouble wrapping my head around the physics involved

The key to wrapping your mind around the physics is to create a Free Body Diagram (FBD) (search the term). If you do that for two different length arms, your mind will be wrapped. We will be happy to assist you in doing this.

 

[Nik_2213]

IIRC, a garage or similar work-shop would deploy an adjustable lifting beam, such that 'unbalanced' load is shackled to the ends, but hoisting eye may be moved along beam to balance point by winding threaded rod.



Due Care, Please ??

 

[Lnewqban]

Does torque that is countered add force required to lift a load?

Only when the moving parts are not perfectly aligned to be parallel in all planes.

 

[Baluncore]

I know the offset force will create a torque, assuming the mass is captive in a track of sorts, in this case a roller guide, would it be safe to assume the torque is cancelled out and wont add to the force required to lift this mass?

So long as all the surfaces that the rollers run on are vertical, the roller forces must remain horizontal, so there can be no vertical component of the roller force, that could change the force needed to support, lift or lower the mass.

 

[Big Tommy C]

Awesome, I understand now. Thanks for the help on this guys!