How to graph Sine wave in excel?

[Guest]

I'm going to try and make sense out of all of this. I'm doing a lab report
and I need to graph the Lead/lag Output vs. angle of rotation of Input for
U-joints. The graph is supposed to look like a sine wave. Here is the
equation that correspond to the previous sentence: tan(theta
out)=cos(alpha)*tan(theta in). tan(theta out) is the lead/lag output and
tan(theta in) is the angle of rotation for input. My graph keeps looking
like an elliptical type of curve. Maybe I'm going about this wrong but
hopefully somebody can tell me the excel formula so that it will graph a sine
wave..if possible. Thanks!

 

[Dana DeLouis]

I don't know for sure, but in your equation:
Tan(out) / Tan(in) = Cos(a)

Tan(90 Deg.) is infinity, so this may be throwing your curve off. Some
plots don't do well when passing thru Tan(90 Deg) as the output jumps from
+Infinity to - Infinity.

Is the above equation correct?
HTH
Dana DeLouis

 

[Tushar Mehta]

If you plot your function as a function of alpha, you will get a sine
wave shaped result scaled by tan(theta-in).

If you plot it as a function of theta-in there is no way to get a sine
curve shaped result.

The only information I could find about u-joints was in an automotive
context. For a single cardan joint -- whatever that means -- the
equation is

Woutput/Winput = cosB/(1-sin^2sin^2[A])

where

B = angle between the shafts

A = rotational angle of the input shaft

The above comes from http://www.eng-tips.com/viewthread.cfm?qid=90372
which I found by searching google.

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions