How to Know the Length of a Flat Spiral Spring.sw2016

Hello

With a little bit of tutorial thinking and perseverance, I managed to draw a flat spiral spring.

but now I don't have access to the unfold function to know its developed length (thinking that there could be material removals in certain places and therefore know the precise location).

so I would need your enlightenment.

Friendly.

Syrius


part2.sldprt

Hello@cil dede_1

Look at the attached image and you will have one of the possible answers with SW.
The other solution is to calculate with a fairly simple formula. One of my watchmaker friends uses this frequently and the formula also gives the stiffness of the spring, this allows you to check the solution proposed with SW, it also allows you to check that the elastic limit conditions are respected;-)

Kind regards


mesure_dune_spirale_2021-04-11_16_19_54-.sldprt.jpg
1 Like

Hello

Yes but you don't have the development with the loops in this way.

I use this function with the inner edge and the outer edge and then divide by 2 to get the neutral fiber.

But what I would like is to be able to unfold the piece.

Friendly.

Syrius

Have you tried to convert the spiral into sheet metal before doing the machining?

1 Like

Hello @cil dede_1

Before affirming " you don't have the development with the loops in this way"

Just read this
1°) The three sketches that you use to draw your spring are fortunately in the center of the rectangle that you use for the sweeps, which means that all the numbers correspond to the neutral fiber so no need to do this ""inner edge and the outer edge then I divide by 2 to get the neutral fiber.""

So you have to do a complicated  calculation which is length of the three sketches  Spiral + sketch 4 + sketch 6 which gives 3.57+1.79+408.54 it says nothing about the K factor

Be careful because for springs there are other parameters related to heat treatment to take into account (shrinkage or elongation)

Goodbye

1 Like

Hello

for Stefbeno, yes I tried but he refuses me the function.

for Zozo, I don't know, if I explained myself well in my way of calculating, but I find the same thing in practice and as for the stiffness due to TTH or the elasticity of the material is not a priority for the moment but it's true you're right.

What I would like is once finished is to be able to unfold the piece.

Friendly.

Hello

Too bad @ac cobra isn't there!
I take up one of these ideas


2021-04-12_19_10_24-_-_ac_cobra_1208_pp_009_-_rep_1_-_piece_pliee_cryla.jpg

Yes, but we don't talk about the same thing anymore in terms of design.

Ben! If you want to have your spring flat, this is a method.

 

Hello

I work 99% in sheet metal mode for my designs to which I have no problem for a flat layout both in sketching and in drawing (see attached file).

and so I'm looking to do the same thing with a flat spiral


Part3.SLDPRT

Good evening

I submit to you as an attachment a model of a balance spring with the sheet metal module (in 2018 version).
Its length can easily be known as early as the construction of the basic sketch (Sketch6).
In the end, it is of course rollable/unfoldable...
Kind regards.


springspiral2018.sldprt
5 Likes

Hello

Attached is a document on 2016 that should help you in your approach.

Kind regards 


ac_cobra_427.sldprt
1 Like

Hello m.blt and ac cobra 427,

Here you have it, your designs really look like what I'm looking for, but not being a seasoned fan of SW, would you have the opportunity to make me a tutorial of your designs in video.

For ac cobra 427, when I open the file I have 3 errors in sketch 3 5 and 7 is this normal and also why the turns are cut on 180°

thanking you in advance.

Syrius.

Hello

The errors come from the fact that you had created blueprints on the extrusions and as I removed them this bug. Solidworks doesn't know how to unfold turns but semicircles so I redesigned semicircles on your coil by making them tangent to each other and respecting your diameters. You can also go directly through a standard sketch and create your coil directly with semicircles.

1 Like

Hello

I hadn't entered that you had taken over my basic file (the numbers are put at random because it was just for me to understand).

I may ask a silly question, but I need to understand: you say that SW doesn't know how to unfold coils so why on m.blt's plan we manage to unfold all the spiral body.

CDT

Syrius

I just looked at the file that was posted and it's a solution that I didn't know about and that I think is simpler than the one I proposed because it avoids having to redo the sketch.

So she wasn't that stupid as her no question.

On the other hand, would it be possible to have a video tutorial (preferably) of the m.blt file or a step-by-step tutorial written version.

Kind regards.

Syrius.

1 Like

Hello
Your desires are orders, Monseigneur...
The "tutorial" is attached.

M. Blt


ressortspiral.mp4
3 Likes

Well what can I say except a big thank you.

great work at least there I can soak it up and try to understand all the functions.

and thank you again.

Syrius.

On the other hand, just a little clarification.

Is it possible to draw the inter and exter loops and to have a function to join the 2 ends in elipse mode and to indicate the number of revolutions wanted.

CDT.

Syrius.