Calculating Torque needed to raise an object

[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.

Thanks in advance

 

[kolleamm]

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.

 

[sophiecentaur]

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.