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curve by equation

S

sanjeevkar1

New member
hello guys and gals


following is a picture of two types of curves one with circle and other with ellips. can these two curves be made by curve by equation. if yes please post me the equations


PS. image is of Auto CAD (sorry for that)
smiley2.gif






View attachment 3994
 
If your intention is to model a SPLINE, model one and pattern. Making it is arcs and circles may not satisfy continuity and tangency.


If you can elaborate on the final product, we can give a more focused solution.
 
srini





these curves are tengential to each other (though not clear in image) and it is in one plane.i want a equation to make these kind of curves
 
I don't understand why you want to over-complicate things defining the whole sketch with a complex mathematical equation (I doubt you'd be able to derive one).


Model a 'patternable' segment of the sketch and then if you really need to do so, you could make a copied datum curve (using apprxiamte solution, not exacts) and pattern this using an axis pattern. You would need to ensure that the segement was a proportion of your finished skect in order to make sure your end points coincide.


Phil
 
Hi,


I got a doubt in that, is there any possibility to copy the sketch from autocad to Pro-E i the sketcher window. I think its possible.
 
phil


if you consider the regeneration time; the curve made my equation will be much more faster then the pattrened curve. i need this to be by equation as i have to pattren them in Z direction to make a stack kind of thing.


please anyone master in trignometry. solve my problem


smiley19.gif
 
ashok





it is possible that you tranfer the A CAD file in Pro/e but then you have whole lot of week dimensiond and constraints to deal with





AVOID IT
 
my god sanjeev,


I wrote a long reply, but it has not appeared at all...


---------------


Coming to the point, your curve cannot be defined as a single equation but by TWO equations using two different co-ordinate systems. You cannot define it from single co-ordinate system because a unique solution will not exist. i.e for any value of theta, a unique value of R will not exist.


Hence you will have to define it as two different curves, One for the Crest and another for the Valley. As regards Trignometry, it is simple.
 
http://www.geocities.com/klivlend1/curves.html


Gives fun looking at the pro-e results.


you can even copy & paste the equations directly!


srini:-


'hypocycloid' gear lobe setscan be created from this single equation:-


z=0


x=(a)*cos(t*360)+b*cos(-c*t*360)


y=(a)*sin(t*360)+b*sin(-c*t*360)


real number parameters a and b and c need to be available:


for an 8 lobe rotor:- try a=7; b=0.4; c=7


BTW experimentation is better than 'spoon feeding'
Edited by: jbuckl
 
jbuckl


thanks for the website anf the equation but it is not solving my problem can you please give me equation that can make the curve i want to achive.





sirini


i am waiting for your equation(s)
 
see below:-


http://www.geocities.com/klivlend1/curves.html


Gives fun looking at the pro-e results.


you can even copy & paste the equations directly!


srini:-


'hypocycloid' gear lobe setscan be created from this single equation:-


z=0


x=(a)*cos(t*360)+b*cos(-c*t*360)


y=(a)*sin(t*360)+b*sin(-c*t*360)


real number parameters a and b and c need to be available:


for an 8 lobe rotor:- try a=7; b=0.4; c=7


BTW experimentation is better than 'spoon feeding'
smiley36.gif
 
thanks jbuckl


got your PM ang the curve is good now i have to do some hit and trial method to get the exact curve i want





thanks a lot
 
jbuckl said:
srini:-


'hypocycloid' gear lobe setscan be created from this single equation:-
Click to expand...
Dear Buck,


Firstly Thank you verymuch for the link. It helped me on certain other requirement of mine.


A Hypocloid or an epicycloid is ONE CONTINUOUS Curve created by circles moving without slipping on the Inside / outside of a circle.


Sanjeev's requirement was that it should be composed of ARCS tangent to each other with CENTERS lying on the periphery of the circle. An arc by itself is continuous as referred to its OWN center or to any other reference POINT. Hence my understanding is that for HIS particular requirement it sould be composed of two different sets of curves. Hence my reply.
 
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