Multi-Rotor Drones
Multi-Rotor Drones include all aircraft with more than one rotor. The most prolific variant is a quadcopter (four blades) but hexacopters (6 blades) and octocopters (8 blades) are also fairly common within the commercial segment. In most cases, there will be an even number of motors/blades. Tricopters and Pentacopters do exist but are seen much less often.
These aircraft are commonly seen in the commercial sUAS industry and are well suited for everything from hobby flying to industrial inspections.
Quadcopters
Quadcopters are, by far, the most popular type of multi-rotor drone. They offer a good blend of lift capability, low weight, and stability. However, not all quadcopters are the same, in fact, there are multiple different configurations. The various types are quite similar but have a different propeller layout and slightly different frames.
- Most popular
- Lightest
- Long motor arms
- Camera mounted underneath
- Heaviest
- Low torsional stiffness
- Camera mounted in front
- Lighter than H, heavier than X
- Optimized for front camera
- Improved torsional stiffness
H (and Hybrid H) frames provide more space for avionics components but also weigh more and have lower torsional strength. Each frame type has compromises but the X Frame is by far the most popular due to its combination of structural rigidity and low weight.
Hexacopters
Hexacopters are generally more stable, able to lift larger payloads, more resistant to wind, and provide a higher level of safety than a quadcopter. Due to the additional motors, most hexacopters can land safely in the event of a motor failure.
Octocopters
Octocopters are the largest of the commonly seen sUAS. They provide significant lift and are capable of carrying heavy, complex payloads such as studio cameras, LiDAR units, and agricultural sprayers. However, this power comes at a cost; octocopters usually have multiple large battery packs and lower endurance than quadcopters.
Flat Octocopters are the most frequently seen type of this segment. They are comparatively simple and provide a large amount of lift and good stability.
Octo-quad (X8) is similar to a quadcopter design. It has four arms but 8 total rotors, the lower of which have a reversed rotation direction. This has the benefit of creating additional lift in a smaller footprint than a normal, flat-octo configuration.
Octo-V (V8) is an example of a non-standard octocopter design. This aircraft, the Intel Falcon 8, has a patented V Frame design that allows for a low weight to payload ratio and good stability.
The amount of total lift generated depends on multiple factors but, in general, the more airfoil surface area a multi-rotor aircraft it has, the more lift it can generate.
More Props = More airfoil surface area
More airfoil surface area = More Lift
More Lift = More Payload