Can Carbide cut a spiral and offer a progressive depth of cut?

[Rxman (Tom)]

What I am attempting to do is to create a continuous spiral whose depth cut gradually deepens to allow for a marble to self motivate within the spiral track. Thinking of a marble game or a rube-golbert type of whimsical device. Ive got the circle tool and the Offset tool , but scratching my head on converting circles to spirals if possible.I am using either or carbide create or vcarve desktop. Tom

[WillAdams (William Adams (Carbide 3D))]

No, Carbide Create does not support this at this time. Not sure about Vectric Vcarve.

I’ve put in for this as a feature request — allowing cutting a contour at an angle would enable some interesting design options.

The only way this could be done in Carbide Create would be as a V carving which was drawn as a closed contour and which was defined using a continuously narrowing contour.

If you defined the cut as a no-offset contour in Carbide Create it would get exported as a series of straight line moves — it should be workable to either edit by hand (tedious) or write a program to edit in the Z-depth to have this increase the Z-depth for each successive line — at that point though, you might as well write a program which would do this directly. If you’re interested in that, what programming languages do you like to work in?

[WillAdams (William Adams (Carbide 3D))]

Macromedia Freehand did have an Xtra tool for drawing such spirals:

which had a pretty cool interface for defining how they were drawn:

which would import as:

and which imports into Carbide Create fine:

[Gerry]

Hey Tom,

For the VCarve side of this, it’s possible if you have access to a 3D model of an inverted cone, or can make one.

Here’s a possible set of operations using tools that are free except for VCarve Desktop.

Make a spiral in a similar manner that @WillAdams suggests by using the spiral tool in Inkscape:

Pop the following code into the genius that is OpenSCAD:

 $fa=0.1;
 difference() {
   cylinder(h=4, r1=1, r2=19.5, center=false);
   cylinder(h=4.1, r1=0.8, r2=19, center=false);
 }
 

Adjust the heights and radii to suit, then hit F6 and export it as an STL. It makes something like this:

In VCarve (I used VCarve Desktop), import the STL into VCarve and then import the spiral SVG made in Inkscape.

Then create a profile toolpath for the spiral and click the “Project toolpath onto 3D model” checkbox.

You should be able to end up with something like this:

[Mogsy (Wayne Alan Morton)]

Vcarve have a flute tool paths that does increase the depth of cut over a given distance
I have played with it to get longer less aggressive chamfers
I’m sure it could be adapted for a spiral

[Gerry]

lol… well, that’s a lot simpler. I’ve never even clicked on that toolpath type before. It’s pretty great

Thanks @Mogsy!