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how to draw a spring

  • Thread starter Thread starter parul.kohli
  • Start date Start date
Paolo,

Is it just me or do you really like using VSS and relations?
smiley2.gif


Great tips, though!
 
jvidal said:
Is it just me or do you really like using VSS and relations?
smiley2.gif

Ahaha yes it's true, basically I don't like using the menu manager, so I miss a lot of great tools, and try to compensate with others :D
 
skraba said:
Thanks, works like a charm.

How do you blend the straight parts with the spring? You build a connection curve and do the VSS through the entire length?
 
One thing to remember is that most compression springs are closed, that is there is a flat portion at either end. What I do is to create a curve by equation and calulate the z dimension from a graph. The equation in the curve looks like this:


/* For cylindrical coordinate system, enter parametric equation
/* in terms of t (which will vary from 0 to 1) for r, theta and z
/* For example: for a circle in x-y plane, centered at origin
/* and radius = 4, the parametric equations will be:
/*&nbs p; r = 4
/* theta = t * 360
/*&nbs p; z = 0
/*---------------------------------------------------------- ---------
R=(OD-WIRE)/2
THETA=TURNS*T*360
Z=evalgraph("SPRING",(T*TURNS))


In the graph I start with a little horizontal for the flat sectionat 1/2 the wire diafrom zero to .5 turns, from .5 to 1 turn I go from 1/2 wire diameter to 1 1/2 wire diameter to represent the closed coil, then I havea line to the other end where I have a similar construction. All the values in the graph and in the curve equations are controlled by dimensions in an outline sketch of the coil and the TURNS parameter I added. After the curve is created I create a VSS for the solid.
 
thanks Paolo; its too good..





now i have to try to make those loops on both ends
smiley2.gif
 
PRStock said:
One thing to remember is that most compression springs are closed, that is there is a flat portion at either end. What I do is to create a curve by equation and calulate the z dimension from a graph. The equation in the curve looks like this:


/* For cylindrical coordinate system, enter parametric equation
/* in terms of t (which will vary from 0 to 1) for r, theta and z
/* For example: for a circle in x-y plane, centered at origin
/* and radius = 4, the parametric equations will be:
/*&amp ;nbs p; r = 4
/* theta = t * 360
/*&amp ;nbs p; z = 0
/*---------------------------------------------------------- ---------
R=(OD-WIRE)/2
THETA=TURNS*T*360
Z=evalgraph("SPRING",(T*TURNS))


In the graph I start with a little horizontal for the flat sectionat 1/2 the wire diafrom zero to .5 turns, from .5 to 1 turn I go from 1/2 wire diameter to 1 1/2 wire diameter to represent the closed coil, then I havea line to the other end where I have a similar construction. All the values in the graph and in the curve equations are controlled by dimensions in an outline sketch of the coil and the TURNS parameter I added. After the curve is created I create a VSS for the solid.


Peter


i tried your way but i am not getting the graph right. can you please (please please
smiley9.gif
) upload a image of your graph.
 
zpaolo said:
skraba said:
Thanks, works like a charm.

How do you blend the straight parts with the spring? You build a connection curve and do the VSS through the entire length?


The spring itself and curved ends are not blended, in fact there are gaps between them. I have just created trajection curve from the endpoint of the spring (helical surface) and on planes parallel and normal to that end, since I don't need exact geometry, just to order more or less standard spring and to show basic shape of the spring.
 
loop is done. now iam waiting for Peter's response to my last post.
smiley4.gif
 
Peter,


Any chance you could save the PowerPoint in 2003 or earlier? We're stuck here on 2003 version.


Thanks
 
Sometime back I had created a compression spring with sqared ends. Using some basic mathematics, I had derived an equation for varaible pich between end of first closed coil and begining of third coil. I could able to generate the entire spring with just one featue that is Helical protrusion. For some strange reasons, I am controlling the free length of the spring through a paramter called "Total_length" given under paramters. Rest of the parameters are defined in "relations" window. Please feel free to coment on the modeling technique.


2009-08-05_211452_parametric_spring.prt.zip


I have suppressed
 

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