"The centerline of a single coil of a canted coil spring can be defned by the parametric
Equations1:... "

Given the parametric equations, a script should be possible to create a curve of the centerline. (Based upon a very brief look
at the equations...)

A sweep with a circle would resemble the physical coil. Not sure if it would be exactly the same.

Should try Flow?

The spring is not canted until it is inserted in a circular groove...

Thanks, bemfarmer.

I read the same possiblities in that sentence! But I don't know how to script it.

I just checked out Flow, which (probably due to the missing icon) have skipped
my attention. Not sure how that is going to do it though (although it looks completely amazing).

Even though they are not in my hands yet,
The springs seems canted all the time:

http://www.flickr.com/photos/artofprecision/5269761425/

M

Hi Morten, I think it should be possible - if you want to give it a try check out the sine wave script from here:

http://moi3d.com/forum/messages.php?webtag=MOI&msg=1519.38

That creates a curve that is formed by plotting a bunch of points along a sine wave function, you should be able to adapt that to use the functions from that thesis instead. It should be a good starting point anyway.

- Michael

Here is a quick flow.
Do not know if it is the same in the physical world.

1. Construct a circle of diameter 10
2. Construct a line of length 10*PI =~ 31.41592653589 (by typing in the value in the___ box.)
3. Create a helix of say 10 turns, radius say 2, using the line as a length snap.
4. Run flow by selecting 1. helix, 2. line, 3. circle.

Edit, whoops I think I made a toroid. Need to constrain the coil a rectangle...???
Ignore this post.

Also check out the ToroidalHelix one:
http://moi3d.com/forum/display.php?webtag=MOI&msg=1519.12

That's a similar type of thing. Check out the .js files there to see the script code that is plotting points at increasing parameters of a function and then it takes all those points and builds a curve out of them.

You should be able to follow the same general pattern for your case, you need to do some stuff like figure out what parameters you want to expose in the UI and stuff like that.

- Michael

You can also use Flow to introduce a shear effect, that might help give you the kind of shape you want before wrapping it around a circle like Brian shows above.

To do a shear using flow, set up a base plane under your object, and then make a copy of the plane over to the side, turn on control points of the plane and shift them to make a parallelogram type shape, like this (also see attached 3DM file):



Then you can select the helix, run Transform > Deform > Flow - pick the plane that is right under the helix as the base surface, and then next pick the slanted one as the target, that will produce this kind of result:



- Michael

Thanks a lot. From a quick test, the Flow method with skewing works nicely!

I tried to modify the Sinus Curve script, but got an error (attached).

Best,
Morten

Hi Morten,

> I tried to modify the Sinus Curve script, but got an error (attached).

What was the error?

Also it looks like you also need to attach the CantedCoilSpring.htm file that has the UI in it too, in order for me to be able to do a test run over here.

- Michael

By the way you also might be interested in this other discussion thread that shows how to use Flow to introduce compression or expansion of coils too:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4876.2

- Michael

These are very cool springs. They make great electrical connectors in medical devices, and electronics.
Of the many patents, Peter J Balsells is one of the main creators.

In one patent, the springs are not just a simple helix of steel which is pushed into a groove, circular or otherwise.
During the winding, different angles are created in the steel.
Contrary to this, the thesis formula appears to be symetrical in the z axis...

For a script, I would make the assumption that the spring runs along a straight line, not a circle, and then use flow. (?)

One iteration would make one coil, of 1/w offset.
To script along a circle, I think would require another equation, which would rotate each coil around a polygon, (or circle).
The polygon would have the same number of sides as number of coils.
Or the circle would have to have the correct circumference to accomodate an integer number of coils...

Michaels method looks excellent for viewing the circular canted coil.

A script would be fairly easy, I think.

Here is a simple menu:

Hi Brian, does that one match the script above? It looks like they have different names - CantedCoilSpring.js versus CantedToroidalHelix.js ...

- Michael

Sorry, it is the same htm.

I've dropped toroidal thoughts for now.

Wrote a canted helix script, but of course it does not work.
It sort of worked for a while, but now I've completely broken it. :-)
I always get messed up with t = 1/(number of something). And number of coils per unit length.

Got the CantedHelix script to work.
It was necessary to adjust the formulas.
(The use of w had to be modified.)

Picture:

I suppose it could be turned into a toroid, without too many hours of work?

Hi Brian, yeah what about using Flow to bend it around a circle like you showed earlier in this thread?

- Michael

Flow should work great!

I'm curious if the skewed helix is the same as a canted one...

The script does't set the length like the MoI helix command can...

Yes, these are very cool springs! Making a lamp that can twist... Still very much in progress.

The script works perfectly in combination with the Flow function.
Thank you very much, both of you.

Best,
Morten