Equation Curve Involute

[jmfowler1996]

Hi, guys. I am trying to create a true involute curve for a gear tooth.

Strangely, when I use the equation curve function and input the equation, I seem to get the involute of some other circle.

The equation I used was as follows:

X(t) = d2 * ( cos(t) + t * sin(t) )

Y(t) = d2 * ( sin(t) - t * cos(t) )

taken from Wolfram

[Anonymous · Accepted solution]

You are using degrees instead of radians as input to sin and cos.

Open the part

Edit the sketch

Right click on curve->Edit Equation Curve

Select 'Show Units'

note that cos and sin have degrees, not radians   -> "d2 * ( sin(1 deg * t) - t * cos(1 deg * t)"

You can manually replace 'deg' with 'rad' in the edit box.

Also, reduce the 't' value upper evaluation down from 900 to 20 or so, or you will be waiting a while.

 

[jmfowler1996]

Haha, what a rookie mistake!

I really never considered that. I just assumed Wolfram's equation would be in degrees.

Thanks for the solution. I'll make sure to check for things like this in future!