Finding tangential force exerted by a rotating cylinder at a given point.

AI Thread Summary
The discussion focuses on calculating the tangential force exerted by a rotating cylindrical CNC machine tool with specific dimensions and mass. The user attempts to derive this force using the moment of inertia and torque formulas but encounters discrepancies in their calculations, particularly regarding the moment of inertia and the rotational speed. It is pointed out that the correct formula for the moment of inertia of a cylinder is I = 1/2 mr^2, which may lead to an underestimation of torque and force if misapplied. Additionally, there is confusion about the rotational speed used in calculations, as the user mentions 2000 rpm but calculates with 1200 rpm. Clarifying these points is essential for accurately determining the tangential force.
gauravmech1
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Consider a vertical cylindrical CNC machine tool with mass of 0.75Kg, 0.015m diameter and height of 0.025m.

It is rotating at 2000 rpm.

While rotating it cuts some material. This cutting action takes place due to tangential force applied on the workpiece as shown below:

[URL]http://C:\Users\GAURAV\Desktop\Paper[/URL] applied jrnl\cutting analysis sorted paper

From the given data can we fing the tangential force being exerted by the tool on the workpiece.

In short we have to find the force which will be applied by any point on the periphery of the tool due to is mass and roatating motion.

is this approach right:

N=1200
ω=(2∏N)/60

MoI of cylinder abt axis I=mr/2
Torque T=I.ω
also T =F*r

Hence F is found but it comes very small. Hence I doubt is this tangential force or any other and what is the right approach.
 
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gauravmech1 said:
MoI of cylinder abt axis I=mr/2
The moment of inertia of a cylinder about its axis is ##I=\frac{1}{2}mr^2## not ##I=\frac{1}{2}mr##. Maybe the formula you quoted is a typo on your part maybe that's where the problem is. Certainly underestimating the moment of inertia will underestimate the torque and hence the force. Also, you say that the cylinder is rotating at 2000 rpm but then you use 1200 rpm for your calculation of ##\omega##. Is that also a mistake or does the cylinder slow down from 2000 to 1200 rpm when it starts cutting? Without the benefit of seeing your calculation in detail, we will not be able to help you sort this out.
 
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