The entire process of making large acrylic ancient building models
The double-layer Chinese ancient architecture model undertaken by our factory is made entirely of 5mm thick new material acrylic board, with a 1:30 ratio that fully presents the flexibility of the upturned eaves and the exquisite carving of the window frames. To achieve a 90% restoration rate, the entire production process integrates CNC precision cutting and manual finishing. The main structure alone was disassembled into 218 acrylic components, which took 35 days to complete.
1、 Material screening and drawing analysis
Firstly, strict screening of raw materials is carried out, using brand new acrylic sheets with a transmittance of 92% to ensure that the entire model is crystal clear and free of impurities. The technical team disassembled the original architectural CAD drawings in layers at a scale of 1:30, focusing on the key parameters such as cornice rise angle (15 °), arch of wooden architecture spacing (2.5cm), window lattice pattern (combination of ice cracks and rhyming patterns), and converted them into a laser cutting path file. Specifically for the roof tile surface, a 0.3mm wide tile seam marking line is pre-set in the drawing to simulate the stacking effect of traditional tiles.
2、 Main structure laser cutting
Fix the acrylic sheet on the CNC laser engraving machine and cut the base, columns, beams, roof and other components in sequence according to the layers. When cutting, the "layered cutting method" is used: first cut through the protective film on the surface of the board, then cut it to 2/3 of the thickness of the board with a power of 300W, and finally manually break it along the engraved line - this can avoid yellowing of the edges caused by high laser temperature. The connection end between the column and the crossbeam is pre cut with a mortise and tenon structure. The diameter of the male mortise and tenon is 0.1mm smaller than that of the female mortise, and space is reserved for glue filling during splicing. After the cutting is completed, workers wear powder free gloves to inspect each piece and manually trim the edges with 2000 grit sandpaper to ensure that all right angle turning points are polished with a 0.5mm arc transition, which not only prevents collisions but also enhances the transparency and refraction effect.
3、 Detail carving and hot forming treatment
The most time-consuming is the production of arch of wooden architecture and cornice. The arch of wooden architecture part first uses laser to carve the outline of "Dou, Gong and Ang", then the teacher holds a tungsten steel cutter to carve the "roll kill" radian under the magnifying glass. A single arch of wooden architecture needs 12 carving processes. The smallest "Shutou" (decoration on the top of the arch of wooden architecture) is only 1.2cm high, but it needs to carve three layers of arcs. The eaves adopt the "hot bending shaping process": the cut acrylic eaves board is placed in a constant temperature heating box and kept at 65 ℃ for 10 minutes until softened. It is quickly transferred to a customized wooden mold and fixed with a fixture for 2 hours to cool and shape, ensuring that the 15 ° lifting angle error does not exceed 0.5 °. Decorative parts such as Wadang and Chuxiong are first 3D printed with photosensitive resin master molds, then turned into silicone molds, injected with transparent acrylic solution, cured, and manually polished to match the transparency of the main board.
4、 Splicing assembly and seamless processing
Splicing is carried out in a dust-free workshop, and the workbench is laid with positioning drawings in a 1:1 ratio. The acrylic base plate is fixed with magnets. First, install the column base and column, apply acrylic special glue to the column bottom (note 0.2ml along the mortise and tenon joints), and ensure that the perpendicularity deviation is ≤ 0.3mm with the help of a square; then splice the beam frame and the arch of wooden architecture layer by layer, and adjust the height of the connection between the arch of wooden architecture and the beam with 0.1mm thick transparent acrylic shims to ensure that each arch of wooden architecture is aligned on the same horizontal line. When splicing roofs, pre apply fluorescent adhesive at the tile surface marking to reinforce and simulate the shadow effect of traditional tile joints. After all the splicing is completed, use a special acrylic polishing paste to perform "mirror polishing" on the interface. First, remove the adhesive marks by rough grinding, and then use a wool wheel to polish until it is transparent and seamless. Finally, achieve the effect of "integrated molding from a distance and clear texture from a close view".
5、 Transparency verification and finished product protection
Finally, place the model in a customized lighting box and check the uniformity of light transmission from six directions: the shadow deviation between the column and the beam frame should be ≤ 1mm, and the window frame carvings should not deform under backlight. After the verification is passed, the whole body is sprayed with nanometer dust-proof coating, and then the acrylic display cover with buffer cotton is installed. The bottom is embedded with an adjustable LED light band. After the power is turned on, the whole model is bright. The shadow of cornice and arch of wooden architecture casts a complete outline of the ancient building on the background wall - this is the unique "virtual reality" effect of acrylic material, so that the charm of the millennium ancient building can be reproduced in transparent light and shadow
