PhoDrone 1 – Long Flight Time (1h), Aerial Photography Quad, 770mm 17inch

RC Groups

Centerboard

The center board has been glued with HK CA glue (HC-50-175). A small frame with screws through the four beam holder holes kept the sandwich layers aligned.
Note: Better do large areas with this glue outside as it generates a fume that is biting in the eyes. I assume it’s not healthy as well 🙂
Using nylon spacers and screws, the top and bottom sandwich were assembled.

Beams

The beams were machined with a 1/32″ flat end mill and cut to length in the last run.
M3 nylon screws lock the beams and act as breaking point when crashing.

Electronics

To attach the electronics to the center board, I chose two different approaches. Components which will not be used in every flight have been attached using Velcro. The other components were glued directly to capton tape I put to the center board. The ESCs were wrapped in capton tape to prevent short circuits. I hope the heat dissipation is reasonably low with the 30A ESCs.

Sandwich Glue

  • HK CA glue (HC-50-175)
  • Loctite Vinyl, Fabric & Plastic Flexible Adhesive
  • HK 30min Slow Cure Epoxy
  • 3M General Purpose 45 Spray Adhesive

Sandwich Bend Test

  • 100x10mm x 1mm CFK, 3mm Fill, 1mm CFK

CFK 1mm, 3k plain weave carbon, orientation parallel (0°/90°) to centerline
Fill +/-45°

Bend test showed best adhesion and no separation up to 6kg for HK CA glue (HC-50-175). All other separated well below this (usually at around 3-4kg). However glueing is tricky for large areas such as the center board.

Endurance

During the first flights, the flight time was reasonably high at a bit over one hour with 1555 props.

Crashing

Arms folded away during the first crash (I’d love to call it unplanned rapid decent though :-)) and the M3 nylon screws broke as planned, preventing damages to the rest of the drone.

Flight Time

With this setup, flight times above one hour have been achieved, even including the 180g 3-axis gimbal and GoPro.

In the diagram below various test flights for a 15″ 5.5 and 17″ 6.0 propeller were aggregated to show the effect the prop choice has on flight time.

Bill of Material

Amount Description Link
6
rctimer 5010 360kv
NA
3
Multistar Lipo Pack XT90
Amazon
4
Flyduino KISS
Amazon
4
1760 Folding Props
Ebay
1
Flight Controller and Power Module
Hobbyking
1
GPS witd Compass
Amazon
1
Receiver
Amazon
1
Damping Balls
NA
1
Folding GPS Antenna Base/Black
Ebay
1
Lipo Voltage Checker
Amazon
1
FPV Camera
Amazon
1
VTX
Amazon
1
Telemetry Radio
Amazon
1
Skyfpv Video Switch
NA
1
OSD
Amazon
2
LC Filter
Amazon
1
FPV 3 Axis CNC Metal Brushless Gimbal With Controller For DJI Phantom GoPro 3 4
Banggood
1
GOPRO
Amazon
1
pigtail
Amazon
1
Silicone Wire
Amazon
1
FPV Antenna
Amazon
1
Transmitter
Amazon
1
Goggles
Amazon
2
Goggle Battery
Amazon

 

LiPo Battery Value and Capacity

Flight time depends mainly on the drone weight. In order to get flight times above 1 hour on a single charge (as shown here), the weight has to be minimized. Typically the most dominant weight hereby is the battery.

  • Value can be calculated by Capacity / Price)
  • Density can be calculated by Capacity / Weight

The diagram above is sorted left to right by Ranking = Cap /Weight * Cap /Price