Torque vs Weight: Calculate Force for 6.156 kgf cm, 20 rpm, 5 cm Rad

In summary, the conversation is about determining the weight that a motor with a torque of 6.156 kgf cm and operating at 20 rpm can move forward, given a tire radius of 5 cm. The equation provided by Cloudswords uses the power of the motor to calculate the required power to move the vehicle on a level surface. Using this equation, the weight is calculated to be between 122 and 19.5 kg.
  • #1
cloudsword654
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Hey, I was wondering
If I have a motor that can supply 6.156 kgf cm of torque operating at 20 rpm, how much weight can that engine move forward given that the radius of the tires will be 5 cm? Please provide equations. Thanks
 
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  • #2
Hi Cloudswords-
First, let's convert the motor parameters to power. the torque 6.186 kgf cm is 0.604 Newton-meters, so the power is 0.604 Nm x 20 x 2 pi/60 = 1.26 watts. The power to move the vehicle on a level surface is the velocity times the force to push it, which is 0.01 times the weight W (in Newtons) times the velocity (m/sec), where 0.01 is the expected rolling resistance coefficient of the rubber tires. Using direct drive to the tire, the velocity = [STRIKE]0.104[/STRIKE] 0.658 meters/sec, so the required power is 0.01 W x [STRIKE]0.104[/STRIKE] 0.658 = [STRIKE]0.00104[/STRIKE] 0.00658 W watts.

So 1.26 watts = [STRIKE]0.00104[/STRIKE] 0.00658 W watts
So W = [STRIKE]1211[/STRIKE] 191 Newtons ([STRIKE]122[/STRIKE] 19.5 Kg)

[Edit] See table of rolling resistance coefficients in Table near bottom of
http://en.wikipedia.org/wiki/Rolling_resistance

Bob S
 
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  • #3


I would be happy to assist with your question. To calculate the force generated by the motor, we can use the formula: Force = Torque / Radius. In this case, the torque is given in kilograms-force centimeters (kgf cm) and the radius is given in centimeters (cm). However, for consistency, it is important to convert the torque to a standard unit of torque, such as Newton-meters (N*m).

To convert kgf cm to N*m, we can use the conversion factor of 0.0980665 N*m per kgf cm. Therefore, the torque in N*m would be 6.156 kgf cm x 0.0980665 N*m/kgf cm = 0.603 N*m.

Plugging this value into our formula, we get: Force = 0.603 N*m / 5 cm = 0.1206 N.

So, with the given parameters, the motor can generate a force of 0.1206 Newtons. Keep in mind that this calculation assumes ideal conditions and does not take into account any external factors that may impact the force generated by the motor. I hope this helps answer your question.
 

FAQ: Torque vs Weight: Calculate Force for 6.156 kgf cm, 20 rpm, 5 cm Rad

What is torque and how does it relate to weight?

Torque is a measure of the twisting force applied to an object. It is directly related to weight because the weight of an object determines the amount of force needed to rotate it.

How is force calculated from torque and weight?

Force can be calculated from torque and weight using the formula F = T/r, where F is the force in newtons, T is the torque in newton-meters, and r is the radius in meters.

Can you provide an example of calculating force from torque and weight?

For example, if we have a weight of 6.156 kgf (kilogram-force), a torque of 6.156 kgf cm (kilogram-force centimeters), and a radius of 5 cm, the force can be calculated as F = (6.156 kgf cm) / (5 cm) = 1.2312 kgf = 12.312 N (newtons).

How does speed (rpm) affect the force calculation?

Speed, also known as rotation or revolutions per minute (rpm), affects the force calculation by changing the amount of torque applied to the object. As the speed increases, the torque also increases, resulting in a higher force value.

Is there a limit to the amount of weight that can be rotated at a certain torque and speed?

Yes, there is a limit to the amount of weight that can be rotated at a certain torque and speed. This is because as the weight increases, the amount of torque needed to rotate it also increases, and there may be a point where the torque required exceeds the maximum torque that can be applied.

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