4 answers

• 
  Michael Mauldin 11 months ago

  There a couple of ways this can be done.

  First is that you can create a law curve based on expressions for x and y and a separate law curve for you z values. The expressions for the x and y values are formulas for the x and y values of a circle multiplied by the number of coils, i.e. x=rad*cos(t*360*number_coils) and y=rad*sin(t*360*number_coils). "t" is a built in expression that tells NX to evaluate the formula from 0 to 1. For the z value you can create a sketch that directly plots the values of z. Look at the attached part for an example.

  Another way is to create a cylinder whose diameter equals the diameter the spring minus the diameter of the wire and whose length is equal to the spring length. Then, on a datum plane that is tangent to the cylinder create a sketch that is the "unwound" path of the coil. Use "wrap curve" to map this sketch onto the cylinder and then create a "tube" using the wrapped curve. You can get rid of the cylinder and create flattened ends by offsetting the cylindrical wall to make it larger than the spring and doing a boolean intersection of the cylinder and tube. Example part attached.

  Attachments

  comp_spring_simple.prt, 380 KB
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  compression_spring_template_3.prt, 636 KB
  Download

  comp_spring_simple_2.prt, 352 KB
  Download

  1. 
     haripal 11 months ago

     Micheal, Thanks. The second method (with cylinder) works. But in first one, there are some problems while creating the law curves and expressions.

  2. 
     haripal 11 months ago

     Micheal, first method works but it not creating variable pitch. even I tried the same expressions as you provided in attachment.

  3. 
     Michael Mauldin 11 months ago

     Can you upload your model so that I can take a look at it?

  4. 
     haripal 11 months ago

     i have to create a spring with following specifications.
     no. of turns=29
     pitch=1.05mm
     wire dia.=0.5mm
     dia. of spring=4.5mm
     total length of spring=42.7mm
     there are 2(29-2) coils, 1 at top and otger at bottom of 27 coils, having pitch 0.1mm.
     how to create this spring?

• 
  Michael Mauldin 11 months ago

  The original model I uploaded was for a straight wound spring. I apologize for not making that clear. To get a variable pitch the sketch must be modified to control the pitch in a variable manner. Attached are two sketches, one that is progressively wound and one that is a two stage spring. You will need to edit the sketch as needed to get the desired result.

  Attachments

  haripal_spring_1.prt, 668 KB
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  haripal_spring_2.prt, 672 KB
  Download

  1. 
     haripal 11 months ago

     Thanx. In 'LAW CURVES' there are different types- by equation, by law curve; which requires the curves or edges. since, I don't know the procedure of these commands(never gone through law curve before this) , I am not getting it properly.

• 
  haripal 11 months ago

  michael, I uploaded 'model1'. please tell me the corrections

  Attachments

  model1.prt, 136 KB
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• 
  Jess wuhuan 5 months ago

  How to Creat Springs in NX6.0?There are some equations for that,but when i inputed them,a dialogue block which shows there is some problem for "+" always came out,and i couldnot proceed,could you please give me some solutions?