I really like that rigatto (small straight line engravings) that create that silky sheen effect on jewelry such as that done by Buccelati. After seeing the textures and meshes that can be made with Gemvision matrix art, I was curious if anyone has had tried this before? It would be interesting to see how close one could get to the effect of hand made rigatto lines. I imagine the limitation is more from the casting since there would be loss of detail. I suppose larger rigatto or florentine style textures would survive the production.
As you rightly said, the loss of detail would be in casting. But the details will be lost at 3stages: at the 3Dmodel resin output, the wax piece, the casting and then even in filing and polishing. If the bright cuts of the florentine finish are subdued, then the whole point of the texture will be lost.
We tried as an experiment to repeat the details by making a mould of a silver model with florentine finish, and then casting a piece, but the result was really not even worth describing.
Nope. We hand engravers still rule this small piece of the pie.
Yes, I’m sure hand engraving is still the best and maybe the only way.
But… that being said… I decided to make the small rigatto lines in Zbrush after I make the design in Rhino. One day, we will have perfect powder metal 3d printing or sintering (Direct 3d printing in metal)…
So If I can create exactly what I want in Zbrush, in the future I will be able to create the item in theory. The resolution needed is probably decades away?
We shall see.
Does anyone know which shaped engraver the Italians use when they make the rigatto engravings to create that “silk” effect on gold an silver? Is it an onglette for example and approximately what size is ideal?
Thanks, have a great day.
If you are talking about a florentine finish which is small lines that intersect each other at right angles or just the lines that all run in the same direction. I use a line graver. It is a flat graver that has lines cut into its belly. You only sharpen the face and it cuts from 4 to 10 parallel lines depending on what size you choose.
Yes it is possible to achieve a florentine effect using Matrix/Rhino, and obtain a satisfactory result.
The restrictions here would be Position of the texture and Size of the article.
Leaving aside the two above mentioned, the key then is width and spacing of the tools used to create depth.
This is where most CAD user will discover that the visual effect on-screen will greatly differ from the produced physical item. All of us who use CAD/CAM will be ever so familiar with this visual proportional issue.
Overcoming the loss of detail and polished/textured/low sheen areas ( talking here about a simple basic surface) is all a matter of working backwards from the desired effect in the finished item (at the planning stage), and understanding the limitations of the CAD tools chosen to produce the florentine pattern. Generally the cross-hatching shows a better result in the finished solid article if the different directions are at differing depths and are not at 90 degrees.
By the way Gerry the Cyber Setter: keep up the jolly good work. Glad to see you still at it.