Architectural model of Querétaro

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Architectural Model of Querétaro City

In March of 2018, Pablo Artasánchez a local sculptor and sixth generation of glodsmiths from Puebla, came with a government project of creating a bronze model of the colonial downtown of Querétaro in Mexico. The whole model will have the siez of 14m x 10m and he came to Luis and me in Fablab Puebla because he had the idea of using digital fabrication to do all of the pieces so he could create models to pour the bronze. The challenge: Our part, producing 47 square blocks of router CNC facades, 150 3D printed pieces of church facades, statues and church domes and 47 square blocks of laser cut roofs. The project was massive and it had never be done in any part of the world with this scale and this size.

Luis and I assembled a team of 15 people: 13 modellers that digitized all of the square blocks facades, sculptures, statues, and churches facades and domes. They did this part of the project in Rhino using photos and google earth and maps. Then Luis was in charge of CNC routing all of the facades. I was in charge of 3D printing the 150 pieces and Alejandra was in charge of laser cutting all of the roofs.

The difficulties and learnings I faced as leading the 3D printing process of pieces were many. We only had 5 printers and one month to print 150 pieces. We had 2 Sindoh printers, 2 ultimaker printers and Rostock Max V3; the first difficulty was to make all the printers print in the same quality or as close as you can't tell there were made in different printers. The other difficulty was that some pieces had floating pieces and needed support, but that rose the printing time 4 hours; when each piece already was at least between six to eight hours, adding four more it would make it impossible to print the 150 pieces in one month. We also didn't have much time for mistakes, repeating pieces could make us not deliver in time, and the possible errors were many: the material may run out, the printer may get stucked, the piece can unstick of the printing plattaform, etc. I had to think in the proper printing orientation and also played with the walls and filling parameters that I could omit the supports and if some details of the pieces melt, the walls and the surface could hold with not so many mistakes.

All the facades were made in CNC Router and it depended on the size of the block but each board of PVC can hold between four or six blocks and it took from 24 to 36 hours for the router to mill one board. The problems we faced were regarding the details, at first the pieces were a little blurry on the lines, but then after adjusting the speeds and feeds of router we got so much details that the bronze pouring won't get it, so we needed to reduce the details directly on the 3D models, and the designers had a couple of days to adjust every model.

Regarding the roofs, we approached as doing a volumetric model in laser cut to give volume and height so we could close every model. This part was easy to design and cut but very hard to assemble, it was like a puzzle because every block had an specific amount of rectangular pieces of specific sizes to make the roofs.

The project couldn't be finished in the quality that it was if it wasn't for the knowledge of the sculptor and goldsmith ArtaSanchez. The molding and casting in bronze was also very complex, creating each sand mold was a challenge and assembling the roof puzzle was very difficult. But in the end we finished in the two months that were set.

Upper picture shows the 3D print of three pieces of a shower tower. It was faster to cut the tower in three than printing one single object with supports.

Upper picture shows a beautiful arch of a downtown portals.

The upper picture shows the detail of one of the tests of the facade. And on the back of the PVC facade we can see another test in wax. In the end we chose PVC.