ThongPaDisp: An open-source 3D-printed shuttlecock dispenser using a Grip-Gate-Push mechanism

This paper presents ThongPaDisp, a low-cost, open-source, 3D-printed shuttlecock dispenser developed to automate shuttlecock feeding. The Grip-Gate-Push mechanism implemented in ThongPaDisp overcomes the limitations of conventional Grip-Gate (gravity-only) dispensing systems, which are prone to jamming caused by feather deformation and interlocking within the shuttlecock stack. The device is a modular feeder designed for integration with a shuttlecock launcher or standalone operation. The extraction sequence is actuated by three independent servo motors synchronized via a microcontroller. Two operating modes are supported: (1) automatic dispensing triggered by hand detection beneath the device, and (2) manual control via a wireless infrared remote for testing. The experimental evaluation utilized both new and used shuttlecocks across five repeated-dispensing trials. Under the Grip-Gate (gravity-only) configuration, jamming occurred in 3.3% (95% CI: [0.0%, 11.9%]) of trials for new shuttlecocks and 40.0% (95% CI: [11.9%, 68.2%]) of used shuttlecocks, with a mean fall time of 0.29 s. Conversely, the full Grip-Gate-Push configuration significantly improved reliability, exhibiting 0% and 1.7% (95% CI: [0.0%, 5.4%]) jamming for new and used shuttlecocks, respectively, with a mean release time of 0.61 s. The lightweight ThongPaDisp design (0.45 kg) is released as open-source hardware to enable easy fabrication, modification, and further development.