Brief introduction of "Show Car"
A show car, sometimes called a dream car, is a custom-made automobile created specifically for public display, and not for sale. It is typically shown at auto shows and other exhibitions.
Producing a perfect show car in 30 calendar days can really be considered ‘Mission Impossible’.
1. Project Background
August 25th, 2014, BAIC decided to produce a show car for the 2014 Guangzhou International Auto Show. The D80, based on the D70 design, is a luxury business car model. It was given a lead-time of only 30 days. The D80 is much wider and longer than the D70 and has a more luxurious interior. At the project kick-off, the detailed design of D80 had not yet been completed; only the appearance aspects had been confirmed. The client was only able to provide a D70 chassis as the base; meaning we had to split and reconstruct it to make it longer and wider. All of the outer shells, exterior decorations, interior coating and functioning accessories had to be produced and assembled; and that’s what we did.
2. Project Challenges
1) High level of complexity: 712 parts needed to be produced, tested and assembled.
2) Complex procedures for repainting: The original paint had to be removed in order to adjust the form of the sheet metal, apply putty and polish, and align with other parts. The entire car was then repainted.
3) Seat redesigning and cladding: The filler material of the seat is made of sponge, which is very difficult for processing. We needed to match the set frame provided by the client with the sponge, mount them together, and ensure that it would be electronically adjustable.
4) Front and rear cover strength assurance: Considering the strength requirements and exterior streamline, we evaluated and decided to use glass fiber-reinforced plastic as the base material.
5) Front and rear windshield: In order to ensure the best performance, glass was used instead of acrylic, we used actual toughened glass and screen printing. This provided the best effect.
6) Sunroof construction: The D70 chassis provided did not feature a sunroof, therefore we needed to produce it by hand. A technical challenge was to guarantee the location and the accuracy in order to prevent deformation of the roof.
7) Wheel hub integral forming: The show car had to run and be drivable, therefore the wheel hub needed to be able to bear the load. We produced the wheel hubs by whole processing, with a CD pattern surface effect and piano painting.
8) Clearance arrangement: For cladding parts, carbon fiber parts and water transfer printing parts, we had to allow for clearance in our 3D model, in order to prevent assembly problems due to increased thickness from treatment processing.
9) Incomplete data input: Our client was only able to provide some ‘A-side information’ and related model. A-side data comes from reverse engineering; it does not represent engineering data as it is without any mechanical or mounting structure. For this project, 70% of the data was A-side data. We needed to refine and redesign in order to meet the final requirements.
10) Wide-range of technologies: In this project, we used all of the processing technologies in the field of rapid prototyping, such as coating, hot stamping, color painting, carbon fiber, water transfer printing, CD pattern, screen printing, laser carving, spraying, electroplating, etc…
11) Limited production cycle: Normally, producing a show car of similar complexity requires approximately 50 working days.
12) Highly complex assembly: Most body modification work was completed by hand. Several locations had to be changed as they could not reach the designated position. The original installation holes were misaligned, which led to great installation difficulty.
13) High quality requirement: As this was to be a demonstration car for an auto show, the quality demands (lines, radius angle, gap, clearance of the surface, electroplating, spray paint) were all extremely high, with no defects permitted.
3. Project Solution
1) A project management team was set up for this urgent and challenging project. Our main engineering team was immediately gathered in order to analyze and evaluate the entire project and assign responsibilities. The project manager was responsible for the entire project arrangement and coordination. The project team members also included manufacturing engineers, mechanical engineers, project engineers, customer coordinators, QC engineers and purchasing engineers. The project manager was responsible for verifying all production conditions, managing project meetings, assigning all responsibilities and authority, communicating with clients, meeting project deliverables according to the approved timeline, and supervising project implementation.
2) Clarify customer demands and develop acceptance criteria. The surface effect of the product was provided along with a list of required materials and design renderings. Through analysis and observation of the renderings, combined with the material definition and the surface effect, we translated the customer requirements for an exquisite appearance and standards throughout the production and inspection process to ensure the information well received.
3) Production orders for all parts had to be prepared. Through detailed communication with the client and deep understanding of project requirement, we put all parts into various stages of sub-assembly, then confirmed detailed specifications for each sub-assembly. We clarified the material, process and assembly relationships for each part and assigned dedicated engineers to be responsible for specified parts.
4) Careful schedule planning. Tight timing meant that accurate project progress tracking would be required for every part and working procedure; accurate to within the hour.
4. Production Implementation
1) The design only defined the appearance and material of the vehicle. No information was provided for process plan or assembly gap control. To avoid interference issues in the assembly process, we produced large parts and components and first assembled them with the chassis. Smaller components were produced according to the assembly, and then grinded and adapted where required.
2) The sunroof was produced manually, by adjusting the chassis sheet metal, applying putty and grinding, and modifying contour lines.
3) As the car body was manually modified, there were errors compared to the theoretical 3D data. Meanwhile, certain components were produced by CNC machining. The tolerances of the chassis and the CNC-machine components caused more assembly difficulties. One such challenge arose when we initially planned to assemble the machined roof first and then match it with others accessories. During our first trial, however, we discovered a 20mm gap error in the width which was due to the D70 chassis being narrower than the D80’s design. We had to adjust the gap by splitting the roof in the center section. We were faced with many such obstacles throughout the project, which were all solved with continuous communication with the client.
5. After-treatment Process
1) After the assembly of all structural parts, the vehicle needed several levels of manual polishing. We ensured curvature of the surface and streamline, painted the entire vehicle, and provided other various surface finishing details.
2) Leather coating is the most complex and time-consuming coating process. Since leather materials have soft and natural texture, the seat and steering wheel and the door interior usually require leather coating. Leather coating on each position and each layer were repeated several times to achieve an immaculate effect and tactile impression. We fully understand the importance of the cosmetic appearance.
3) The surface coating process of a show car is significantly different from that of mass production. Painting is done manually by professional craftsmen, compared to spray-painting robots. Paint has to be perfect without any defects, as the car will be in the spotlight on show. The reflective effect of the coating and color also must be perfect.
4) Plastic parts are normally painted using a two-component paint. The surface effects are divided into matte finish and high glossy. The paint color should be uniform, with no particles, pitting, scratches or other defects. High gloss finish pieces require the even thickness, clear, with no oil flow.
5) Electroplating is a technology used to apply a thin layer of metal to a surface using electrolysis. Electroplating requires special texture and uniformity of the material. The basic material must be a single piece with a perfectly smooth surface finish in order to ensure plating quality.
6. Final Assembly
1) After we had produced 712 parts, the final step was to assemble them to produce a perfect car. Assembly was conducted in a dust-free workshop. After 3 days of hard work and careful assembly, the finished show car was assembled in accordance with the planning sequence.
2) After final assembly, every part of the show car was meticulously cleaned by hand.
7. Transportation and Delivery
After 30 days and nights of challenges, successes and hard work, we finally completed the project on time and with perfect quality. We are proud of all the obstacles we managed to conquer. Even the client suggested that it would be “MISSION IMPOSSIBLE” to successfully deliver on time.
8. Show Car Exhibition
On the Guangzhou 2014 Auto Show, the BAIC D80 show car won the praise of all. The client sent us a formal letter acknowledging our excellent service, and their intent to seek further cooperation with us.
With the successful experience of D80 show car, we optimized our production procedures for show cars. With detailed project information, we set up a show car project standard flow chart. We believe we can implement future show car projects more efficiently.
Based on the successful show car project, we earned the trust of the client. In the next two years, we helped the client fulfil five show car projects. A difficult initial project led to a win-win result.
Duke Du (Project Manager)