spiral spring: am I drawning in a glass of water?

coldby · 23rd June 2006, 07:33 AM

Drawing a spiral coil: before I tryed I was bluntly sure that a few mouse clicks would do it. Now I'm not as sure anymore.
Mind you, not a helicoid, a true spiral: the radius gradually increasing or decreasing, but all on the same plane - the kind of spring you still find in old-fashioned mechanical clocks or toys.

Dennis · 23rd June 2006, 10:25 AM

I thought there *may* have been a way to do this using Replicator --- I can't see a way to offset the extrusions where they make a spiral, however...

I needed this functionality a while back, and as it wasn't in AC3D already, I ended up getting "Spiralizer":

http://www.armanisoft.ch/webdesign/FrmDownloads.html

Scroll to the bottom section and click that Spiralizer link if you don't understand German.

It exports to DXF, which loads nicely into AC3D. Good workaround until there's a way to do this natively in AC3D...

captainj2410 · 23rd June 2006, 11:36 AM

You could still do it manually by moving the vertices in a helicoid inward while still keeping close to the same plane they were on and keeping an eye on the distance moved display.

coldby · 25th June 2006, 08:42 AM

Thanks folks, mostly for confirming that the Alzheimer hasn't had me yet

And, Dennis, thanks for Spiralizer - guess I'll have it downloaded and tested before the Sunday's over.
Anyway I muddled through by applying the old-fashioned trick (from the times of ruler and ink) of drawing a set of concentric circles with decreasing radii, deleting three quarters of each, rotating and assembling together the remaining arcs, drawing (manually!) a path along the vertices and then eventually extruding the cross-section along the latter. Pretty dirty indeed, and it took a helluva time - but the final result really looked like a spiral.

Dennis · 25th June 2006, 10:16 AM

One other method worth considering:

To mimic the 2d shape of a spiral in AC3D, I followed the steps from the attached image:

1. I pulled the image of a spiral off the web ( http://images.google.com/images?q=spiral )
2. Loaded the image in the AC3D Front view using Ortho -> Set Background Image, then traced the spiral image using a Line.
3. Subdivided the Line.

The Spiralizer will be better if you're going for more mathematic precision, or for spiraling the spring "upward", but this is probably a faster/easier way to get a basic spiral...

eldonb · 25th June 2006, 12:22 PM

Dennis,

Could this be a need for a more "generalization" of your wave plugin?

23rd June 2006, 07:33 AM	#1
coldby Senior Member Professional user Join Date: Jun 2006 Posts: 102	spiral spring: am I drawning in a glass of water? Drawing a spiral coil: before I tryed I was bluntly sure that a few mouse clicks would do it. Now I'm not as sure anymore. Mind you, not a helicoid, a true spiral: the radius gradually increasing or decreasing, but all on the same plane - the kind of spring you still find in old-fashioned mechanical clocks or toys.

23rd June 2006, 10:25 AM	#2
Dennis Senior Member Professional user Join Date: Jul 2003 Posts: 899	Re: spiral spring: am I drawning in a glass of water? I thought there may have been a way to do this using Replicator --- I can't see a way to offset the extrusions where they make a spiral, however... I needed this functionality a while back, and as it wasn't in AC3D already, I ended up getting "Spiralizer": http://www.armanisoft.ch/webdesign/FrmDownloads.html Scroll to the bottom section and click that Spiralizer link if you don't understand German. It exports to DXF, which loads nicely into AC3D. Good workaround until there's a way to do this natively in AC3D...

23rd June 2006, 11:36 AM	#3
captainj2410 Senior Member Professional user Join Date: Aug 2005 Location: Captain's Quarters, Deck 1 USS Avenger NX-101468 Posts: 792	Re: spiral spring: am I drawning in a glass of water? You could still do it manually by moving the vertices in a helicoid inward while still keeping close to the same plane they were on and keeping an eye on the distance moved display. __________________ http://jamietakahashi.deviantart.com

25th June 2006, 08:42 AM	#4
coldby Senior Member Professional user Join Date: Jun 2006 Posts: 102	Re: spiral spring: am I drawning in a glass of water? Thanks folks, mostly for confirming that the Alzheimer hasn't had me yet And, Dennis, thanks for Spiralizer - guess I'll have it downloaded and tested before the Sunday's over. Anyway I muddled through by applying the old-fashioned trick (from the times of ruler and ink) of drawing a set of concentric circles with decreasing radii, deleting three quarters of each, rotating and assembling together the remaining arcs, drawing (manually!) a path along the vertices and then eventually extruding the cross-section along the latter. Pretty dirty indeed, and it took a helluva time - but the final result really looked like a spiral.

25th June 2006, 10:16 AM	#5
Dennis Senior Member Professional user Join Date: Jul 2003 Posts: 899	Re: spiral spring: am I drawning in a glass of water? One other method worth considering: To mimic the 2d shape of a spiral in AC3D, I followed the steps from the attached image: 1. I pulled the image of a spiral off the web ( http://images.google.com/images?q=spiral ) 2. Loaded the image in the AC3D Front view using Ortho -> Set Background Image, then traced the spiral image using a Line. 3. Subdivided the Line. The Spiralizer will be better if you're going for more mathematic precision, or for spiraling the spring "upward", but this is probably a faster/easier way to get a basic spiral... Attached Images

25th June 2006, 12:22 PM	#6
eldonb Junior Member Advanced member Join Date: Nov 2003 Location: Monroe, WA USA Posts: 28	Re: spiral spring: am I drawning in a glass of water? Dennis, Could this be a need for a more "generalization" of your wave plugin?