# Calculating Torque needed to raise an object

• kolleamm
In summary, the conversation discusses the feasibility of using a motor to rotate a robotic arm upwards. The arm is assumed to be a cylinder with an outer diameter of 5.6 cm and an inner diameter of 5.0 cm. Its cross-sectional area is calculated to be approximately 12 cm^2, and its volume is 720 cm^3. The density of the plastic material is given as 0.00124 kg/cm^3. The motor has a torque of 40 kg/cm, but the calculation for the required force is uncertain due to the object not applying force at just one point. The solution involves building a program to run the calculation and considering the speed at which the motor will be running.
kolleamm
I'm trying to find out if my motor can rotate a robotic arm upwards from a resting position (we can assume the arm is a cylinder for simplicity).

The cylinder has an outer diameter of 5.6 cm , and an inner diameter of 5.0cm
Therefore its cross sectional area in that case should be

pi(2.8)^2 - pi(2.0)^2 = 12.06cm^2 let's just say 12cm^2

Its 60 cm long so its volume should be 12 * 60 = 720 cm^3

Also the density of the plastic material is 1.24g/cm^3 or 0.00124kg/cm^3

The motor has a torque of 40kg/cm

I know that Torque = Force * Radius, but in this case I'm a little unsure of how to calculate the force required since the object is not applying a force at just one point.

We can assume the object starts at the pivot and extends its 60cm size across the arm.
Any help is appreciated.

I was finally able to find the solution. I actually had to build a program to run this calculation. The solution is similar to solving the Fibonacci sequence since it requires the data from the previous iterations to check how much torque you have left.

kolleamm said:
check how much torque you have left.
With motors, the torque is dependent on rotational speed so you don't so much have "torque left" but "is it enough". You really need to know the speed that the motor will be running at - or the speed you want the arm to lift the mass. A DC type motor will probably have maximum torque when stationary, which may help. Depending on how near the 'performance edge' you are, you may need to know the torque / speed spec of the motor.
PS Torque is in units of kg cm (a product) and not kg per cm.

## 1. How do you calculate torque needed to raise an object?

To calculate the torque needed to raise an object, you will need to know the weight of the object, the distance from the pivot point (fulcrum) to the object, and the angle at which the force will be applied. The formula for torque is torque = force x distance x sin(angle).

## 2. What is the unit of measurement for torque?

The unit of measurement for torque is Newton-meters (Nm) in the metric system and foot-pounds (ft-lbs) in the imperial system.

## 3. How does the weight of the object affect the torque needed?

The weight of the object directly affects the torque needed. The heavier the object, the more torque will be required to lift it. This is because torque is a product of force and distance, and the weight of the object is a measure of force.

## 4. Can the angle at which the force is applied affect the torque needed?

Yes, the angle at which the force is applied can affect the torque needed. The greater the angle, the more torque will be required to lift the object. This is because the torque formula includes the sine of the angle, which means that as the angle increases, the torque also increases.

## 5. How can I increase the torque needed to lift an object?

To increase the torque needed to lift an object, you can either increase the weight of the object or increase the distance from the pivot point to the object. Alternatively, you can also increase the angle at which the force is applied. However, it is important to ensure that the object is within the limits of your physical capabilities to lift safely.

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