Lightweight Silent Camera Drone

About the project 

My goal was to create a drone that would be able to easily carry a stripped down GoPro while being as quiet as possible. The way to achieve this was to:

• minimize obstruction of the airflow to and from the propellers
• reducing the weight in order to allow for lower motor speeds 
• testing various propellers. 

The minimalist propeller guards are the result of a compromise between safety and the points mentioned above. 

The current iteration weights about 110g without battery (the gopro itself accounts for about half the weight). 

Video 

Video of the drone in action

Filaments

Different parts of the model are designed to be printed in different materials

• PETG-CF or PCTG-CF 
  • Frame 
  • Propeller guard rings
  • Propeller guard ring spacers 
  • Why: Impact resistance and avoiding excessive frame vibrations causing additional noise and suboptimal flight characteristics
  • Might also work with other filaments containing carbon fibers altough I would not recommend PA6/12-CF since it tends to creep after a while.
  • The best choice is to CNC the frame out of 3mm carbon (.step file attached). If you don't own a CNC this can be ordered from various places such as pcbway.com, although it was quiet expensive… If you find a cheaper manufacturer, please let me know in the comments
• TPU
  • Camera platform dampeners
  • Battery strap
  • Ring spacer grommets
  • Why: Without the camera platform dampeners, the propeller vibrations will transfer to the GoPro and cause the dreaded “jello effect” on the recorded footage
  • The ring spacer grommets are designed to avoid the propeller vibrations to transfer to the propeller guard rings and cause addiontal resonance there. 
• PETG 
  • Camera platform
  • Analog camera holder
  • Why: Those parts have no special requirements and are just easier to print in PETG instead of the other two materials listed above

Print Settings

You should be able to print all of the parts without supports, as long as you orient them in a sensible way on the print platform (for example, flip camera platform dampeners to the side)

Post Processing

Depending on you 3d printer accuracy, the holes in the frame might have to be drilled to 2.4mm in order to make sure the M2 screws can move freely in there.

This is especially important for the outermost holes so that the propeller vibration is actually aborbed by the gromets and not transfered to the propeller guard structure via the screws 

Bill of Material

• 25mm hole distance flight controller 
  • e.g. HGLRC SPECTRE F411 12A AIO F411 Flight Controller
    • https://de.aliexpress.com/item/1005007981073435.html
  • Alternative HappyModel X12 5in1 1-2S Flight Controller:
    • https://www.aliexpress.com/item/1005006834409506.html
• Happymodel 1202.5 Brushless Motor KV6400
  • https://www.aliexpress.com/item/1005002357107947.html
• Caddx Baby Ratel Analog camera
• https://a.aliexpress.com/_EwiDoz6
• HQProp T3X3X3 3030 3-Blade Propeller
  • https://de.aliexpress.com/item/1005003500441295.html
•  HQProp T3X2.5X3 3025 3-Blade Propeller (quieter but less grip)
  • https://www.aliexpress.com/item/1005007612761969.html
• BETAFPV LAVA 2S 450mAh 75C Battery
  • https://de.aliexpress.com/item/1005006970316084.html
• NameLessRC 66X45X23mm Naked GoPro Nylon Case and BEC
  • https://www.aliexpress.com/item/1005004028558338.html
• GoPro 9/10/11 to disassemble and turn into a “Naked GoPro” using the case above
• Various Screws
  • 4x M2 16mm screws and 12 nuts for the flight controller stack (might come with flight controller)
  • 16x M2 6mm screws for mounting the motors (might come with motors)
  • 4x M2 12mm screws for attaching the prop guard rings to the frame
  • 8x M2 8mm screws for attaching the rings to the sacers
  • 1x M2 14mm screw for attaching the naked gopro to the camera platform (might come with naked gopro case)
  • 4x M1.4 4mm screws for attaching the camera platform to the camera platform dampeners
  • 2x M1.5 5mm screws for attaching the battery strap

Optional

• M2 25mm Nylon standoffs (more durable than the 3d printed ring spacers) 
  • https://de.aliexpress.com/item/1005003577479911.html
• A few zip ties to keep things nice and tidy