On the eaves of Palazzo Guiccioli, in Ravenna, in spite of the advanced degradation, certain design elements are still present. In order to supply the restorers with a geometric stand, with which rebuild the missing elements, a 3d laser scanning of the best preserved elements has been made.
The shapes which have been first detected by the scanner, through 3d printing, are, then, prototyped in plaster. In fact, the prototype represents an almost exact copy of the scanned element, thanks to the scanner’s high precision.
The scanner model used is ARTEC EVA, chosen for its precision, but also because it can be easily carried and used on a scaffolding where the lack of space for movement causes great problems.
Moreover, a structured-light scanner of this type is also very fast in acquiring and allows a scanning accuracy of up to 0,1mm with a maximum error of 0.03% at a distance of one meter.
The scanning requires about 15 minutes for each separate side.
Each side is made of about 500 scanning frames which, then, are “melted” using a unique mathematics which, after that, is corrected in order to eliminate scanning shadows and eventual errors.
The chosen printing machine is a Zcorp Z650 loaded with plaster, a material which can be very easily handled by the restorers.
The printer allows creating prototypes with a size of 25x38cm and an accuracy of 0.089 mm.
The mesh surface returned by the scanning, after optimization, has been divided in two sides to which a thickness has been given in order to allow the printing.
The creation process is finished in a little more than 5 hours.
Then, the two sides are treated with two component epoxy resin in order to definitely solidify the surfaces.
After the polymerization of the resin has finished, the two sides are glued together and are ready to be delivered to the restorers for the additional processing.
PHASES AND TIMELINES
SINGLE SIDE PRINT_5h
[by Tryeco 2.0]