Help on drawing a compression spring

[rams1937]

Hello,

I am learning ProE using the book entitled "Pro Engineer Wildfire 1 Advanced Tutorial". I am
having difficulties creating the object front_spring in page 2-26. I could do the helical spring with constant
pitch along the axis of the spring. However, I cannot
figure out how to make the ends of the spring flat thru
235 degrees. I tried using revolving protrusion with cutting option, but this would make a flat region of 35 degrees, depending on how I define cutting section profile.

I figured that I would have to vary pitch of spring such
that this values decreases near the ends of the spring.
However, I am trying to figure out if there is a way
to make flat ends of 235 degrees with constant pitch values along the lenght of the spring axis.

Please help.


Edited by: rams1937

 

[AHA-D]

If you want a visual correct compression spring then you need a variable pitch to start with. Add 2 points to each end of the line representing the pitch definition. You need 2 points because ProE makes a transition from one pitch to the other. So you can define nearly flat from point 1 (start) to point 2, make the transition from flat to pitch between 2 and 3, and get a constant pitch between 3 and 4, and then the reverse way for 4-5 and 5-6. Pitch cannot be zero so you add a revolved protrusion toeach end of the helical if you want it real flat.


Alex

 

[geertdaenen]

Hello Aha-D,

is it possible to post an example of a spring you've made by the way explained?
Isn't there a solution in WF3 for this problem, because I also like to "fine tune" my springs.

Kind regards

 

[ReinhardN]

you could us a formed datum curve.
http://www.ptc.com/cs/cs_23/howto/ngf1656/ngf1656.htm
Sketch your curve with varable pitch for the ends and use relations to relate pitch change to turns.
Then make cuts at the ends.
ReinhardN

 

[geertdaenen]

Sorry ReinhardN,


I don't have a login on the PTC-site. Can you put here a file with an example of a spring. So I can figure out how to make it?


Thanks in advance

 

[dr_gallup]

View attachment 4239

View attachment 4240

 

[geertdaenen]

Hi Dr_gallup,


can you place the file here as a zip-file too? So I can see how you've made the curve.


Thanks

 

[wsylvester]

[url]http://www.engin.brown.edu/courses/En174/Exercise/Exercis5.h tm[/url]

 

[wsylvester]

and or


[url]http://www.proengineertips.com/part-design/tutorial-create-s pring-using-helical-sweep-in-pro-e.html [/url]

 

[dr_gallup]

View attachment 4246
Here is the top of the sketch. It is just an axis line, a straight line and 2 extra points to define the pitch. It extends a little above the top datum plane because the next feature is a cut flush with the top datum to model the ground end. The bottom of the sketch is the same as the top.

The amount of spring sticking up above the top datum determines how many degrees of flat results.


Edited by: dr_gallup