Another to?

 From:  Michael Gibson
689.5 In reply to 689.1 
Ok, some steps!

So let's break this shape down into some components. One big part jumping out is that torus / donut shape, let's start with that.

You probably want to turn on grid snap (click it in the bottom bar so it is highlighted in orange), and draw a circle in the top or 3D view, about 10 units or so away from the origin on the xaxis. Then select the new circle, run Construct / Revolve. Pick the first point of the revolve axis snapped to the origin, and the second point on the y axis. That gives you this:

Then I deleted the circle, you don't need it anymore. Then I went to the front view and dragged the torus up a little bit since I want to place the base underneath it and have the base be right at the origin just to make things tidy.

Ok, now for the base. You can draw the base by using Draw curve / Control points. This is generally the main tool for drawing a freeform curve. When you are placing points, you can also hold down the control key or check the "Make corner point" box to make the next point a sharp corner instead of continuing with a smooth curve.

I set the Front view to be full screen, and I turned grid snap off after placing the first point of the curve, then placed a few points and used 2 clicks with the control key to make this shape:

Then select that new curve, run Construct / Revolve again, and pick the revolve axis in the front view first point on the origin, and second point vertical (along the z axis). That will create this:

Then you can delete that curve after the revolve is done.

So now you've got 2 solids with the base punching through into the torus. Select them both and run Construct / Boolean / Union. This will fuse them together into one single solid, the part that was punching through into the torus will be thrown out.

Now for the real "Nurby" part - when you Boolean unioned the pieces together, a new edge was created where the 2 objects intersected each other. You want to select this edge and apply a fillet to round off that sharp edge.

To select the edge (actually it will be broken into 2 edges) - you do a second click on the object. The first click selects the object as a whole. After the object has "full object" selection, you can then do a second click on it to "drill in" to either an edge or face sub-selection. In this case you want to do the second click on that juncture, select both edges there:

Now run Construct / Fillet. This is the cool part! (when it works properly anyway...). When you are in the fillet command, you can either type in a numeric radius, or you can pick 2 points with your mouse and the distance between those 2 points will be used as the radius. You can enter in different radius values until you are satisfied with the result and then push done (or right-click in a viewport).

Here is a radius of 1.0 for example:

Here is a radius of 3:

And that's about it for that one!

- Michael