HQProp Ltd 20x10x3 Propeller

The HQProp 20x10x3 is a three-blade propeller from HQProp Ltd (China) made of glass-fibre composite, according to its title glass-fibre-reinforced nylon, for heavy multicopters. The designation gives diameter, pitch and blade count: 20 in, 10 in, three blades. Adapter rings are included.

Here too the pitch is half the diameter, a rather high value for a multicopter that favours forward speed and loads the motor harder. Three blades raise thrust at 20 in at the cost of efficiency. The weight is 117.5 g. The hub is bored to 6 mm, is 25 mm across and 11.8 mm thick; the adapter rings cover shafts from 3 to 8 mm. The propeller does not fold. At 20 in, motors with a low KV rating and plenty of torque are needed.

Heavy multicopters operate legally at the edge of the open category: up to 25 kg take-off mass including payload operation there remains possible, in class C3 with 150 m distance from residential, commercial, industrial and recreational areas and with direct remote ID. Above that the specific category begins, in which a risk assessment of the operation is required. The propeller is decisive for none of these classifications, but its thrust helps determine the payload.

At this diameter the load concentrates at the hub: inspection covers the play-free seat of the adapter rings, cracks around the bore and the fixing on the shaft. Nicks on blade tips and leading edges change thrust and balance. At 20 in imbalance acts on the motor bearings and the frame; the propellers are replaced in pairs and not mixed with other types.