Realizzazione di una scultura in legno grazie a scansione 3D e CNC

How the “Wooden bust of San Nicola Greco was born”

A statue of the saint was missing

The relics of San Nicola Greco have been kept in the church of San Francesco d’Assisi in Guardiagrele since 1343, but until yesterday there was no statue representative of the saint. The most faithful representation is the simulacrum covered with the typical habit of the Basilian monks, while the face and hands are in ceramic, thus creating the need, on the part of the San Nicola Greco di Guardiagrele foundation, to commission the construction of bust of the Saint.

The commission of a faithful reproduction in wood

The study and research part was handled by a commission in charge formed by the foundation, by Maestro Angelo Catano and by Mons. Giuseppe Liberatoscioli. Which outlined the iconographic and symbolic characteristics that best represented the saint, taking into consideration all the historical, artistic and religious aspects.

The realization was entrusted to the Francesco Carullo di Orsogna company , at the suggestion of the Abruzzese Artistic Handicraft Exhibition of Guardiagrele . In the sculpture project, the most innovative techniques of digital craftsmanship were implemented, making use of the collaboration of experts in the various stages of implementation

3D scanning of the Saint’s relics

To ensure the maximum fidelity of the statue to the existing face, the 3D scanning technique was used, which allows to acquire the three-dimensional shapes, with a precision of 0.5 mm, transforming them in digital drawing . The scanning also involved the ceramic hands belonging to the simulacrum. The habit was worn by a model who posed according to the instructions of the commission, in his left hand a missal was placed. This phase was handled by Simone Carullo , who took care of detecting the shapes and then coupling them, in order to sketch a first digital elaborate in the form of point cloud. 

3D modeling of the project

Subsequently, the digital sculptor Simone Rasetti reworked the scanned geometry using three-dimensional modeling software (ZBRUSH) by reconstructing the missing parts. & Nbsp; With digital technology the sculptor has finished the geometric surface with details and details of the face; the whole process was carried out following the historical documentation and the guidelines agreed with the working group.

From the project to the realization of the work with the CNC numerical control milling technique

The developed saint project was imported into Alphacam CAD-CAM software. The purpose of this software is to generate the paths by setting the appropriate strategy and tools and all other technological parameters. The CNC machine follows the programming codes for the realization of the wooden sculpture . Thanks to this type of woodworking it is possible to obtain pieces with centesimal precision and furthermore the shapes faithfully reflect those of the three-dimensional design

With certain programming and machine setting criteria it is also possible to obtain surfaces with an excellent finish . As for the bust , it was divided into two main parts, front and back and two secondary, the right hand open and the left hand with the book. A roughing and a finish were performed on all parts and the inside of the statue was emptied in order to lighten it, obtaining a weight total of about 50 kg. For the smallest details a 6 mm diameter cutter was used; the programming was subdivided into 26 worktops to create all the undercuts , obtaining a total of about 4.6 million lines . The wooden material was previously prepared through a system of linear sections on the 3D CAD model in order to have exactly the right quantity and dimensions of the wood to be processed. The wood used is sassafras

The final finishing touches of the sacred sculpture

At the end of CNC machining , an accurate sanding and finishing of the details was performed with gouge . The work was subsequently transferred to the laboratory of painter Nicoletta Legnini who took care of the pictorial decoration. The wooden sculpture was prepared for the polychrome decoration by treating the surface by applying a plaster primer by Lefranc & amp; Burgeois, spread in successive layers and carefully smoothed with sandpaper for gilding, in order to obtain an optimal drafting of the pictorial material. Subsequently it was painted with artistic oil and resin paints “Mussini serie 10” by Schmincke. Some details have been decorated with silver leaf , applied with the oil technique (mission). Finally, a light protective varnish with J.G.Vibert Lefranc & amp; Bourgeois extrafine retouching varnish was applied to the work. To complete the project, a mahogany pedestal sapele was applied and on the side surfaces there was a An ancient antiphon in Latin dedicated to the saint has been engraved.