This is my first more or less serious tinkering with Sverchok, the parametric add-on for Blender. So to use this, you need to install Blender and the add-on. Parametric means you can play with values to change the shape. You can do this in three ways (try it with the nodes on the left): - click on the arrows to the left and right. - click in the field to enter a value. - slide over the field. This is best for a first try, to get a feel of what it does. The main value to play with is to the left: 'width to height'. This influences the shape. A higher setting looks better to my taste. Put this on a ring and you can give it to your fiancée. :) To the left is also the size, but you can also alter that after you baked the shape. At a setting of 1 it is about 1.7 mm wide. A more interesting value is to the right, the number of iterations. But be careful, a value higher than 3 (or even 2) may take a long time to calculate. Also, ik makes little sense if you don't print it very big. Even with just 2 iterations, it doesn't make sense to make the model smaller than about 3 cm (which roughly corresponds to a size-value of 18). Else, the top iterations will be too tiny. With 3 iterations it should fill the print bed of an Ultimaker. Lastly, there is 'Segments' in the Bevel-node in the bottom centre. This makes for rounder shapes. And with a value higher than 1, you may also experiment with the Profile-setting (default is 0.5, for a simple round shape). These effects were not my intention, but if it pleases you, who am I to argue. :) Actuallly, 4 segments with a low Profile-number looks quite interesting (although it may be difficult to print). One of the surprises that parametric modelling can lead to. Other settings are not meant to be played with, which is why I put them in collapsed nodes. That is, I can't guarantee it will be printable. (If, however, you just want to just look at the shape on the screen, that is a different matter. In that case knock yourself out; click on a node's triangle to expand it.) The main issue with printability is overhang. The angle of the basic shape should not be a problem on a well tuned Ultimaker. But the iterations should not move outside the top of the previous layer, where they would be unsupported. This is determined by three nodes: the division (by 1.88) at the top left, the float (set to 0.25) in the centre and the formula at the bottom left. This is 1/x**2+2, which makes sure that the value coming out of the node is always between 0 and 2. (Doing it this way also ensures that there will always be an effect; you don't have to search for the values that 'work'.) When you're satisfied with the result: - click 'bake' in the viewer on the right - in the 3D view click the model to select it - with the pointer still hovering there hit hotkey S to scale, enter a value and hit 'Enter'. The dimensions can be seen on the right, in mm. If not satisfied you can alter the scale-value on the left. - export the file as an stl (file > export > stl). Make sure the model is still selected because only selected parts will be written to the file. You can now open it in a slicer to prepare it for print.