# Calculating Torque Needed to Roll 9000lb Roll Across Floor

• scampbel
In summary, Steve Campbell needs to roll a 9000lb roll with a 4.5 feet diameter and 115 feet length across a flat floor. He is looking for the torque required to move the roll, assuming no other forces are involved. After some calculations, he has come up with a torque of roughly 158 lb/ft per end. However, he is not sure if this is correct and is seeking help. The conversation also mentions the relationship between torque and acceleration, as well as the impact of friction on the required torque.
scampbel
I need to roll a 9000lb roll across the ground. It is 4.5 feet in diameter, and is 115 feet long. I am attaching the bold ends to apply torque to move it. I don't need to move it that fast. How much Torque would I have to apply to each end to roll this across a flat floor. Assume that all torque applied is used to roll the drum and nothing else slips or moves. I have a number, I am trying to determine if it is correct. I am coming up with roughly 158 lb/ft per end. Any help is greatly appreciated.

Thanks!
Steve Campbell

It's the basic

$$\Sigma{T} = I \alpha$$

Set your desired acceleration and calculate the required torque from that. That will be a higher number than the torque required to simply overcome friction to maintain a constant speed.

If he assumes constant velocity, then there is no acceleration though, and theoretically the needed torque would be zero. However, one of the main friction forces is from the body deforming.

I remember back from machine design that there are formulas to calculate deflection of spheres and cylinders based on various material parameters. But, even based on a known deformation, I'm not quite sure how to convert that to a friction coefficient.

## 1. How do you calculate the torque needed to roll a 9000lb roll across a floor?

To calculate the torque needed, you will need to know the radius of the roll, the coefficient of friction between the roll and the floor, and the weight of the roll. The formula for torque is torque = radius x force x coefficient of friction. Plug in the values and you will get the torque needed to roll the 9000lb roll across the floor.

## 2. What is the coefficient of friction and how does it affect the torque needed?

The coefficient of friction is a measure of how much resistance there is between two surfaces in contact. It affects the torque needed because the higher the coefficient of friction, the more force is needed to overcome the resistance and roll the 9000lb roll across the floor.

## 3. Can the torque needed be reduced by using a lower coefficient of friction?

Yes, the torque needed can be reduced by using a lower coefficient of friction. This means that the roll will require less force to roll across the floor. However, it is important to note that the coefficient of friction should not be too low as it may result in the roll slipping and not moving at all.

## 4. What other factors can affect the torque needed to roll the 9000lb roll?

Aside from the radius of the roll and the coefficient of friction, other factors that can affect the torque needed include the type and condition of the floor surface, the shape and weight distribution of the roll, and any additional forces acting on the roll (e.g. wind or incline).

## 5. How can I ensure that I am using the correct torque to roll the 9000lb roll across the floor?

To ensure that you are using the correct torque, it is important to accurately measure and calculate the necessary values (radius, coefficient of friction, weight) and double check your calculations. You may also want to consider conducting a test run with a smaller roll or using a torque wrench to determine the exact amount of torque needed.

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