Hello,

My engineering school days are way back, and I'm looking for some help with what I think is a fairly basic problem, but I'm not sure where to
start:

I want to move an object with high precision over let's say 3mm, and space under the object is very limited. I want to use a small motor with gearbox to drive an eccentric, which would push on the object as the eccentric rotates towards higher radius. Let's say the object itself is sitting on the eccentric on one point of contact.

My question is: how do I calculate the torque I need on the motor for the eccentric to generate enough lateral force (upwards) to fight the load (weight of the object)? Let's say, for example that I use an eccentric of 15mm in diamter, with an eccentricity of 9-6 (that would give me the 3mm motion over a full turn)

I believe it is calculated using moments, but not sure where to start here. Any suggestion?

Thanks for your kind help!

My engineering school days are way back, and I'm looking for some help with what I think is a fairly basic problem, but I'm not sure where to

I want to move an object with high precision over let's say 3mm, and space under the object is very limited. I want to use a small motor with gearbox to drive an eccentric, which would push on the object as the eccentric rotates towards higher radius. Let's say the object itself is sitting on the eccentric on one point of contact.

My question is: how do I calculate the torque I need on the motor for the eccentric to generate enough lateral force (upwards) to fight the load (weight of the object)? Let's say, for example that I use an eccentric of 15mm in diamter, with an eccentricity of 9-6 (that would give me the 3mm motion over a full turn)

I believe it is calculated using moments, but not sure where to start here. Any suggestion?

Thanks for your kind help!