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ML_79015751-Visitor
1-Visitor
August 11, 2022
Solved

Help getting this plotted correctly

  • August 11, 2022
  • 2 replies
  • 1433 views

I'm trying to incorporate a cycloid (standard, not epi-) into a design I'm working on. I tried to generate the appropriate curve using the equation from curve tool, but it only returned a very slight curve. I verified my equations using MATLAB. Pictures and equations are provided below:

x(t) = r(t-sin(t))

y(t) = r(1-cos(t))

where t is some angle and r is the radius of the rolling circle tracing the cycloid.

Any help would be greatly appreciated!

Best answer by KenFarley

The problem is that the equations as you have them are assuming the angle being evaluated is in radians.

If you are inputting the angles in degrees (0 - 360), you'll get a very large "X" result.

 

To correct this, again assuming you are setting "t" to be 0 to 360 degrees, the equations should be:

 

x = 1 * ( pi * t / 180 - sin(t) )
y = 1 * ( 1 - cos(t) )

 

This seems to give the desired curve.

2 replies

K
KenFarley21-Topaz IIAnswer
21-Topaz II
August 11, 2022

The problem is that the equations as you have them are assuming the angle being evaluated is in radians.

If you are inputting the angles in degrees (0 - 360), you'll get a very large "X" result.

 

To correct this, again assuming you are setting "t" to be 0 to 360 degrees, the equations should be:

 

x = 1 * ( pi * t / 180 - sin(t) )
y = 1 * ( 1 - cos(t) )

 

This seems to give the desired curve.

    M
    MartinHanak24-Ruby III
    24-Ruby III
    August 11, 2022

    Hi,

    if you set From = 0 and To = 360 for curve from equations then use following equations.

    x=100*(t * PI() / 180 - sin(t))
    y=100*(1-cos(t))
    z=0

     

    Creo uses angle values in degrees, because of this sin(t) and cos(t) is used.

    t * PI() / 180 converts angle value to radians to satisfy cycloid definition.

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