Wrapping 3D models multiple times.

Topics related to wrapped rotary machining in Aspire or VCarve Pro
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Greolt
Vectric Wizard
Posts: 963
Joined: Fri Sep 21, 2007 1:44 pm
Model of CNC Machine: UCCNC Router, Plasma, Laser
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Wrapping 3D models multiple times.

Post by Greolt »

I posted this in another thread, but I thought it might be worth doing a separate thread on this.

The question was how to wrap a model (say a rope) multiple times in a spiral pattern.

There is more to consider when doing this than when vee-carving a design into an existing cylinder.

Because we want the 3D model to stand proud of the surface, then we must devise a way to not recut an already cut area as we come around the second and third times.

Here is an example of one way to lay it out.

This method makes use of the "Wrapped Job Setup" gadget. See first pic.

What you get is a parallelogram shape that when wrapped will make up the cylinder without overlapping itself.

I then made a (very boring) 3D shape and positioned it within the spiral wrap layout. See 2nd pic.

Third pic shows the toolpath view. Toolpath has been constrained to the spiral wrap layout so that it does not recut previously cut areas.

This method works for some very plain 3D models. When the 3D model gets more complex then the layout method needs to be more creative.

Greg
WrappedBoringShape3.jpg
WrappedBoringShape1.jpg
WrappedBoringShape2.jpg

Greolt
Vectric Wizard
Posts: 963
Joined: Fri Sep 21, 2007 1:44 pm
Model of CNC Machine: UCCNC Router, Plasma, Laser
Location: Australia

Re: Wrapping 3D models multiple times.

Post by Greolt »

Here is another method of achieving the same thing.

I prefer this method, or variations of it, for a lot of jobs.

In this example I have set up the job size to the circumference that my finished job will be.

Because I went with a diameter of 100mm, the circumference was 314.159mm. Andrew's circumference calculator is great when doing this.

I have used the same plain 3D model as in the previous post.

Copy and paste the model and then move it via the move dialogue the exact circumference distance. 314.159mm.

Repeat the copy, paste and move until there are enough to cover the required area. See 1st pic.

Place a rectangle vector around the material to constrain the toolpath and calculate. See 2nd pic.

Third pic is the visual representation of the wrapped toolpath.

Greg
2ndBoringWrap1.jpg
2ndBoringWrap2.jpg
2ndBoringWrap3.jpg

Greolt
Vectric Wizard
Posts: 963
Joined: Fri Sep 21, 2007 1:44 pm
Model of CNC Machine: UCCNC Router, Plasma, Laser
Location: Australia

Re: Wrapping 3D models multiple times.

Post by Greolt »

Here is an example of when a parallelogram shape layout as provided by the "Wrapped Job Layout" gadget, will not be adequate.

This 3D snake model was provided by forum member David. It is based on a 2D vector he did and was posted about in another thread.

You can see it will not fit neatly into a parallelogram layout as seen in the first post above.
3DSnake1.jpg
What I have done is use the "copy, paste and move" method as in the above post.

Note the vertical guide lines that show the repeat point on the circumference.

If you look closely you will also see that I have my material a couple of mm larger than the circumference. See 2nd pic.

This gives the toolpath a slight overlap which I find helps making the "Join" disappear.

The resultant model that will be cut, as seen in the 3D view, is the 3rd pic.

Finally the wrapped toolpath in the 4th pic and the cut piece in the last.

Greg
3DSnake2.jpg
3DSnake3.jpg
3DSnake4.jpg
3DSnake5.jpg

Greolt
Vectric Wizard
Posts: 963
Joined: Fri Sep 21, 2007 1:44 pm
Model of CNC Machine: UCCNC Router, Plasma, Laser
Location: Australia

Re: Wrapping 3D models multiple times.

Post by Greolt »

One more example of another method to lay out the snake model.

This time I have started with a parallelogram produced by the "Wrapped Job Setup" gadget.

I then modified that to accommodate the snake's shape. This is a combination of the above layout methods.

The odd looking shape will wrap into a straight cylinder without re-cutting any areas.

Greg
3DSnake6.jpg
3DSnake7.jpg

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