Cam profile from equation

[arlo blair CAS]

Hi all,


I have done my homework and have constructed (simpler) curves from equations before, but am still having trouble trying get the equation for this cam profile into a curve.


For the first 260 degrees the equation is:


r(theta) = (r-0.3) + theta/650


However i write this (syntax) it will not work. Previous examples i have found for creating cam profiles from equations all relate to cos/sin etc.


I am using a cylindrical coords sys.


Any help or links to topics of use would be much appreciated.





Regards


Arlo

 

[trancepose]

one method i know is to generate a curve from equation and copy it in a sketcher window. when you generate a curve, click on curve>from equation select csys and cylindrical as csys type. then write the following into the editor:

r(t) = (actual-0.3) + t/650
theta=t
z=0

insert your reference radius value into actual. this works if theta is in degrees.

 

[arlo blair CAS]

Trancepose (greay name),





Thanks for that, i will give it a go.



Arlo

 

[Zaki]

it is not working man I had tried!!!

 

[arlo blair CAS]

Cracked it:


r = ACTUAL RADIUS- 0.3 + 260t/650


theta = 260t


z = 0


This gives me the first section (through 260 degrees) of my cam profile. I hope this helps to anyone who may be interested (trig could have been used also in the equation).


Arlo

 

[Zaki]

I had make it but I couldnt understand why it is so complex equation for this curve or I had make a mistake. I got this result of this equation


r=50-0.3+((260*t)/650)
theta=260*t
z=0



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