Rapid prototyping is an automated manufacturing process that quickly builds physical models from CAD files of three-dimentional prototypes. It dramatically speeds up design and manufacturing process and substantially reduces the production cost. With the advanced Web technologies, rapid prototyping manufacturing systems can be further integrated and more effectively utilized. We have designed a distributed web platform where users can design prototypes, simulate manufacturing, and issue ordering request for real manufacturing through browser interfaces. However, an improper scheduling approach may degrade system utilization and throughput significantly. To solve this problem, we propose a real-time scheduling approach to maximize system utilization and minimize the average response time with the best effort. Using this approach, new requests can be accepted dynamically and all accepted requests can be finished before deadlines. We show that the scheduling overhead can be neglected and the average response time is very close to the optimal solution. With the proposed scheduling approach, the Web rapid prototyping platform is able to fully utilize Web resources for rapid prototyping manufacturing and the quality of service is significantly improved.