Force Required to Push an IV Pole

Question

So I am working on a personal project that involves an IV pole. In a standard IV pole with lockable casters, there is still some give in the vertical section of the pole. If you apply a force to the top of the pole, it will move a small distance.

How would I calculate the force required to push the IV pole a set distance?

If it makes a difference, I am going to be pushing the pole with a slider-crank mechanism driven by a motor. Really, I want to figure out the torque required for the motor, but I can calculate that myself once I know the force.

I tried to make a force diagram, but I must be forgetting some stuff from school. Can I just assume that the force has to be greater that the weight of the section of IV pole that moves?

Thanks for the help and let me know if you need any clarification on anything.

Answer 1

In the beginning, you apply force but the IV pole doesn't move only the friction resistance increases.

Then the pole jerks into motion and breaks the lock off. Due to the wobbliness of your pole you need to test and measure this force.

After the initial dislodging, the dynamic friction gets involved which is less than the static friction by far. but again in this case it's going to have hick-ups.

Usually, for good casters, the dynamic friction index is in the range of 4% to 10%.

So it would be 0.05*weight approximately. check this graph of force versus friction.