PDA

View Full Version : Coiling a tapered cylinder without overlap or spaces

Seventh Sin
04-12-2016, 08:56 AM
Hi all,

I'm trying to create a model of a coiled up whip I can use to print a ring at a 3D printshop. As such I believe it requires to have all the detail modeled into the object.
What I'm trying to do is have a whip (which is obviously basically a tapered cylinder coil up on itself without any overlap in the object but also without any spacing between the seperate coils.
Attached is an image of what I've come up with so far, but I'm really struggling to get the parts nice and tight to one another.

Just for reference a little write up of what I did sofar..
1.) Create a the strand objects (basically just boxes with a slight bevel).
2.) Line 'm up so I'd end up with a ring like object (in a sort w-shape).
3.) Bend that 360 degrees to get a smooth ring.
4.) Stack these objects on top of each other on the Y-axis resulting in a cylindrical object.
5.) Apply a taper.
6.) Apply a stretch with some falloff zo the angles of the individual "strands" are all roughly 45 degrees.
7.) Apply a bend to the entire object with an offset on the x-axis to get the individual coils to lay next to one another...

However, due to the previously applied taper I can't get the seperate coils to lay tight next to one another.
Any help is greatly appreciated!

133399

PS. I did go through all the topics mentioning coils but I haven't been able to find a solution there. If there's something really obvious I'm missing it might be because I'm only starting modeling again after a long hiatus.

MonroePoteet
04-12-2016, 10:07 AM
I think if you use Detail=>Measure=>Measure Tool to measure the exact gap between the coils at the end, then Undo the Bend, use Rotate to tilt the entire thing up by that much at the end (some fraction of a degree, you could use arctan(gap / length) to calculate the precise angle required) and then re-apply the same Bend (using Numeric panel Apply), it should result in the coils being adjacent along their entire length.

mTp

Seventh Sin
04-12-2016, 01:46 PM
Thanks Monroe!
You just put me on the right track...

Here's how I eventually did it (numbers were trial and error, might try and solve the math behind it some day).
Starting with the long tapered cylinder I did the following:
1.) Rotate -3 degrees over the z-axis
2.) Bend 1.5 degrees over the z-axis ending up with image01
3.) Bend 360 degrees over the x-axis ending up with image02

133401
image01

133402
image02

MonroePoteet
04-12-2016, 03:03 PM
Looks great! Glad to help, but you were smart to do a trial-and-error approach. Experimenting a little with the calculated approach, I couldn't every find a reliable algorithm. The Bend tool doesn't seem to be actually linear (even though the application icons seem to indicate so), which results in the need to slightly bend it down the Z axis as in your step (2) above.

mTp