Spring Modeling Help (Solidworks)

[Helepolis]

Hi all,

Trying to model a spring with both ends closed-&-ground, using the Helix tool and defined by 'Pitch and Revolution'.
I just can't figure this tool out, how the F the parameters in the table work/linked.
various AI chats didn't help, neither google/youtube, nor the laughable "help" of Solidworks, where only the meaning of the different parameters is explained (thanks for nothing!) and not how the feature actually works.

I've never been so frustrated with a Solidworks feature, at a point of just breaking something just the relive the anger.

Just in case here are the parameters of the spring:

• Wire Dia. 1.37mm
• Spring OD 9.83mm
• Total length (end to end) 19.5mm
• Total coils 10
• Active coils 8
• End Type closed-&-ground

Any reference will be more than appreciated, so I can learn Helix feature (specifically the variable pitch).


Thanks,
SD

 

[3DDave]

The YouTube tutorials are pretty obvious; it's more limited than the method I used in Pro/E, now Creo, where the spring pitch equation was described using a curve rather than what appears to be linear interpolations**; it also looks like the Solidworks method is not able to use the overall length as a variable that would allow the spring to conform in the next assembly to the action of the mating mechanisms. This is pretty typical of SW to make something that is easy to get 50% of the way on and then nothing for the remaining 50%. I noticed they manually set the minimum pitch to be larger than the wire diameter, probably to avoid self-intersection. This means the end coils cannot actually be closed as they normally would be for such a spring, particularly with ground ends.

"variable pitch helix solidworks" is what I used to search in google with.

** one interesting variation in Pro/E / Creo was the ability to shift to negative pitch while changing the spring diameter, allowing the spring to wind back down over itself. Never had a need for a spring to do that, but it is something that a wire-bending machine could do. I suppose a pan-cake or clock spring would also be possible, with a pitch of zero and a variable radius smoothly transitioning.

Overall I think that smart tools make users less adaptable.

 

[ctopher]

You can also download a spring model from McMaster-Carr and see how it's done.