Troughed belt conveyors are the standard means of bulk-material transport, and their carrying capacity and spillage resistance depend directly on the trough angle formed by the side idler rollers. Conventional conveyors are built with a fixed trough angle chosen at design time, forcing a compromise whenever a plant handles more than one material or whenever the load on the belt varies over time. This paper presents an auto-calibrating, variable V-angle troughed belt conveyor in which the trough angle of the wing idler rollers is varied on demand by a scissor-screw jack driven by a NEMA17 stepper motor and lead screw. A closed-loop control scheme combines two feedback paths: a rotary-encoder/limit-switch position loop that lets the controller reach and hold a commanded angle accurately regardless of backlash or missed steps, and an ACS712 current-sensing load loop that infers the instantaneous belt load and selects an appropriate angle and belt-speed target automatically. The system self-calibrates its zero and end-stop references at start-up, exposes a 5-button HMI with manual and automatic modes, and halts on an over-current or over-travel fault. The design is intended to reduce spillage under heavy load, improve throughput and reduce mechanical wear under light load, and remove the operator judgement and downtime associated with manually re-angling a fixed-trough conveyor.

Keywords—troughed belt conveyor; variable V-angle; scissor-screw jack; closed-loop control; auto-calibration; stepper motor; current sensing; load-adaptive control.