How to build a spring with variable pitch and compress it?

Roman Legostayev

23 Jan, 2012 01:54 AM

Please click "it worked" if you like it.

1. Step 1:

   Select “Top” plane, create sketch and build a circle with 18mm diameter.
   

   

2. Step 2:

   Click “Curves” and then “Helix and spiral” and enter following parameters.
   

   

3. Step 3:

   Click “OK”.
   

   

4. Step 4:

   Choose “Right” plane, create sketch and build a circle with 1mm diameter. The center of the circle is horizontal with the origin point and coincident with the beginning of the helix.
   

   

5. Step 5:

   Click“Sweep Bose/Base” and select “Sketch2” as “Profile” and “Helix/Spiral1” as “Path”.
   

   

6. Step 6:

   Click “OK” and save the document as “spring.SLDPRT”.
   

   

7. Step 7:

   Open “…/damper/ damper.SLDASM”.
   

   

8. Step 8:

   Click “Insert Components” and choose “spring.SLDPRT”. Insert in random place of the working area.
   

   

9. Step 9:

   Click “Mate” and select 2 planes as shown on picture. Make them “Coincident”. Click “OK”.
   

   

10. Step 10:

    Select plane and face as shown on picture. Make them “Coincident”. Click “OK”.
    

    

11. Step 11:

    Select 2 planes as shown on picture. Make them “Coincident”. Click “OK”. Then click “OK”
    

    

12. Step 12:

    In “FeatureManager design tree” right click on “spring” and select “Edit Part”. Click “Edit Sketch” on “Sketch2”. “View Orientation->Normal To” (or Ctrl+8) and create point as shown on picture.
    

    

13. Step 13:

    “Exit Sketch” and select “Show” in menu of “Sketch2”. Select “Top” plane of spring and create sketch. Select “Center Rectangle” and create a rectangle from the origin point. Select adjacent lines and make them “Equal”. Select line and the point on circle from “Sketch2” and make them coincident.
    

    

14. Step 14:

    “Exit Sketch” and select “Extruded cut”. Choose “End Condition->Through all”. Click “OK”.
    

    

15. Step 15:

    Select the following face and create sketch.
    

    

16. Step 16:

    Select “Sketch3” and click “Convert Entities”.
    

    

17. Step 17:

    “Exit Sketch” and select “Extruded cut”. Choose “End Condition->Through all”. Click “OK”.
    

    

18. Step 18:

    “Exit Sketch”, right click on free space of working area and select “Edit Assembly: damper”.
    

    

19. Step 19:

    “Tools->Equations…”, “Add”. Now add equation for a number of revolutions with constant pitch. R=15.25. because height of part with constant pitch = 61mm and pitch = 4mm (61/4=15.25). “OK”.
    

    

20. Step 20:

    “Add”. Now add equation for a pitch of the spring.
    "P"=(67-"D1@LimitDistance1"+3-
    ("D10001@Helix/Spiral1@spring.Part"+"D10002@Helix/Spiral1@spring.Part")*2)/"R"
    67 – total height of the spring;
    D1@LimitDistance1-limit distance of the tige (double click on “tige” in “FeatureManager tree” then double click on “Mates in damper” and then double click on “LimitDistance1” and select dimension of the limit distance in the working area);
    3 – because the minimum value of the limit distance = 3
    ("D10001@Helix/Spiral1@spring.Part"+"D10002@Helix/Spiral1@spring.Part")*2) – constant areas on bottom and top of the spring (double click on “spring” in “FeatureManager tree” then double click on “Sweep1” and select dimensions “2.5” and “0.5” in the working area);
    R – number of revolutions.
    Click “OK”.

    

21. Step 21:

    Click “Add”.
    "D40002@Helix/Spiral1@spring.SLDPRT"="P"
    Select pitch = 4(double click on “spring” in “FeatureManager tree” then double click on “Sweep1” and select dimension “P4” in the working area).
    Click “OK”.

    

22. Step 22:

    Click “Add”.
    "D10003@Helix/Spiral1@spring.SLDPRT"="P"*"R"
    Select height = 61(double click on “spring” in “FeatureManager tree” then double click on “Sweep1” and select dimension 61 in the working area).
    Click “OK”.
    Click “OK” again.

    

23. Step 23:

    Now drag the bottom part of the damper and then click “Rebuild” (or Ctrl+B).