Chili is a key spice plant in Vietnam, especially in the Mekong Delta, which leads in harvest volume to meet processing and stem separation demands. Existing automatic stem separation systems, designed for popular varieties like Chanh Phong F1, Chanh Phong F4, and Chi Thien, have faced inefficiencies due to uneven chili feeding caused by poorly performing hoppers. This study focused on redesigning the chili hopper to ensure uniform feeding at an average speed of 2–3 fruits per second. The design features two rollers for better chili distribution and a vibration mechanism to prevent clogging in grooves. Key design parameters and roller’s size relationships were carefully analyzed. The relationship between the roller rotation speed, roller size, and system yield was also analyzed and highlighted. A full-scale hopper model was fabricated and integrated into the stem separation system for testing. An experiment conducted on 40 kg of chili (20,851 fruits) successfully eliminated the issue of chilies clustering into groups of four or more during the feeding process. The damage rate of the chili was recorded at 0.21%, indicating a significant improvement in the system's performance. Despite these advancements, the model needs improvements in stability, durability, vibration resistance, and industrial-scale testing.