The Ultimate Guide to Industrial V-Belt Drives: Selection & Tensioning Figure 1: Not all black rubber bands are the same. Choosing the wrong profile is the #1 cause of slip. If you walk into a plant and hear a high-pitched "chirp" or smell burning rubber, you are witnessing wasted money. The industrial V-belt drive is the most common power transmission method, yet it is often the most misunderstood. Engineers often specify "A-Section" belts out of habit, ignoring modern, high-efficiency options. This guide covers Profile Selection , Length Calculation (with VBA) , and the critical belt tensioning method to eliminate belt squeal and premature failure. 1. The "Wedge" Effect: How it Works A flat belt relies purely on friction. A V-Belt relies on the Wedge Effect . As tension pulls the belt into the sheave groove, the side walls push outward, multiplying the normal force. Critical Rule: The belt should NEVE...
In the previous post, Numerical Methods - First derivative using Excel formula, we know how to calculate the first derivative of functions using formula in Microsoft Excel. In this post, let's see how we can simplify it by using Excel VBA code.
The VBA is just like this.
' ================================================
' Created by Suparerg Suksai
' Mechanical Design Handbook
' http://mechanical-design-handbook.blogspot.com
'
' First Derivative - Numerical Methods
' ================================================
Function f(x As Double) As Double
f = 5 * (x - 3) ^ 3 - 4 * x ^ 2 - Sin(2 * x)
End Function
Function fDeriv(x As Double) As Double
Const h = 0.00001 ' Step size
fDeriv = (-f(x + 2 * h) + 8 * f(x + h) - 8 * f(x - h) + f(x - 2 * h)) / 12 / h
End Function
The highlighted (yellow) text is the function that we want to calculate for the first derivative. We can simply replace it with new function. The remaining code still remains the same.
We have to put this code into the Microsoft Visual Basic Editor in Microsoft Excel (Alt+F11). Now we're going to test this Derivative code. Because the first derivative of the function in this example can be determined by direct method. Then we can use it to recheck the calculation result.
The first derivative of 5(x-3)3-4x2-sin(2x) is 15(x-3)2-8x-2cos(2x). Therefore the first derivative of f(x) where x = 7 must be 15(7-3)2-8(7)-2cos(2(7)) = 183.7265256
Here how to use
In excel spreadsheet, enter =fDeriv(7) and see the result.
We'll use this First Derivative Function in the Newton-Raphson Root Finding Method later.
password: mechanical-design-handbook.blogspot.com
FREE DOWNLOAD EXAMPLE EXCEL FILE
The VBA is just like this.
' ================================================
' Created by Suparerg Suksai
' Mechanical Design Handbook
' http://mechanical-design-handbook.blogspot.com
'
' First Derivative - Numerical Methods
' ================================================
Function f(x As Double) As Double
f = 5 * (x - 3) ^ 3 - 4 * x ^ 2 - Sin(2 * x)
End Function
Function fDeriv(x As Double) As Double
Const h = 0.00001 ' Step size
fDeriv = (-f(x + 2 * h) + 8 * f(x + h) - 8 * f(x - h) + f(x - 2 * h)) / 12 / h
End Function
The highlighted (yellow) text is the function that we want to calculate for the first derivative. We can simply replace it with new function. The remaining code still remains the same.
We have to put this code into the Microsoft Visual Basic Editor in Microsoft Excel (Alt+F11). Now we're going to test this Derivative code. Because the first derivative of the function in this example can be determined by direct method. Then we can use it to recheck the calculation result.
The first derivative of 5(x-3)3-4x2-sin(2x) is 15(x-3)2-8x-2cos(2x). Therefore the first derivative of f(x) where x = 7 must be 15(7-3)2-8(7)-2cos(2(7)) = 183.7265256
Here how to use
In excel spreadsheet, enter =fDeriv(7) and see the result.
We'll use this First Derivative Function in the Newton-Raphson Root Finding Method later.
password: mechanical-design-handbook.blogspot.com
FREE DOWNLOAD EXAMPLE EXCEL FILE
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