Upgraded bracket at a transfer station for Body-in-White post painting process. This bracket was made as an upgrade to an older version causing visual damage to the paint. CATIA was used as design software and Protolabs was used for quick deployment.
During the painting process of vehicles, the chassis is transferred from an elevator to a mobile rack that is transported to the next part of the manufacturing process. 1% of cars were identified as having chipped paint on the bottom edge.
Following the error backward through the process, the origin of the chip marks were found at this transfer station. The original metal pad had a basic design with no alignment. Red coloring is visible indicating the source of paint loss on the vehicles.
Intial hypothesis was that lack of alignment during installation led to imperfect transfers from station to station, scratching paint and pad with the smallest amount of error from the previous mounting.
Several iterations of brackets were designed and printed out of PLA using Bambu Labs 3D printers. 3D printed enabled quick and cost effective iteration on new design concepts.
The second image depicts the cause of the chipped paint: a flange on the edge of each car juts out, serving as the primary area of concern. Because the plastic is realtively weak, imperfect loading helped serve as markers for improved alginment and design.
The final redesign added alignment spots for the vehicle flanges to be placed more consistently. Heavy production periods quickly wore down the bracket near the flange locater, indicating transfer did not have as low a tolerance as originally expected.
Final design of this pad included a widended slot tolerance while keeping the same plastic material selection, allowing for any further error in placement to cause more damage to the bracket than the vehicles in the future. Because of the ease of installation and low replacement rate, custom ordering a low volume of spares ensured production would still be able to run no matter further issues.