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Looks cool, it's great to have another good open source ready-to-fly option. I have some concerns about larger PCB quadcopter designs because I can imagine tha

Looks cool, it's great to have another good open source ready-to-fly option. I have some concerns about larger PCB quadcopter designs because I can imagine that fatigue due to flexing on the PCB over long-term use could cause issues with the PCB delaminating or solder joints failing. On the ArduBee particularly, you can see a lot of surface-mount components mounted on the arms. I'd love to read more about any lifetime testing they've done on the PCB. Of course there's always the risk of just crashing your drone and breaking it, but that's no different than other drone designs!

StavrosK 6y ago
Why would the PCB flex? A quadcopter doesn't have that much of a twisting force being applied to it, no?
- xtagon 6y ago
  Vibration can be a concern with quadcopters especially if the motors and propellers are not properly balanced
  - StavrosK 6y ago
    I guess that's true, and they are using brushless motors so you have quite a bit of power there. Hmm.
  - luminousbees 6y ago
    Till 1 year ago it has been a great concern, especially for small drone. Now thanks to andyp1per, new Ardupilot dev, we have amazing results with dynamic filtering gyroscope noise, we could even track the mechanical noise peak based on actual RPM or live FFT. Harmonic Notch Filter in Ardupilot https://ardupilot.org/copter/docs/common-imu-notch-filtering.htmlhttps://ardupilot.org/copter/docs/common-imu-notch-filtering.html https://ardupilot.org/copter/docs/common-imu-notch-filtering... new and ongoing development https://github.com/ArduPilot/ardupilot/pull/13121 https://github.com/ArduPilot/ardupilot/pull/13121 https://github.com/ArduPilot/ardupilot/pull/14010 https://github.com/ArduPilot/ardupilot/pull/14010
    - DagAgren 6y ago
      This was about mechanical strain from vibration.
      - luminousbees 6y ago
        You have to consider under the selected IMU, in the center, there is the most of the mass, made by the single 18650 Li-Ion battery. This solution is working, ArduBee is already flying good with the low pass filter in the gyro sets at 110Hz, if vibration would be an issue I guess it cannot fly https://discuss.ardupilot.org/t/ardubee-a-ready-to-fly-micro-drone-for-education-and-swarming/54362/11 https://discuss.ardupilot.org/t/ardubee-a-ready-to-fly-micro...
        DagAgren 6y ago
        Again, this issue is not the IMU, it's the whole thing breaking mechanically.
- roland35 6y ago
  Fr4 material is basically fiberglass, and at 1.6mm thick it doesn't take much to bend it if it isn't supported. I think the weight of the motors could be an issue.
  - StavrosK 6y ago
    When resting, possibly. In flight, the weight of the battery would probably be the bigger concern, though I think you can get 2mm PCBs.
    - luminousbees 6y ago
      Thanks! this could be a great idea,the 2mm PCB could be an interesting option! We are devoted to 1.6mm PCB since the 5" version that weighs 220g and we haven't had any broken or issue on the PCB piece. The battery is well attached, fixed in 6 well distributed points on the PCB and aligned perfectly in the center of the 4 motors.
      - StavrosK 6y ago
        That's great then, if it works for you that's all that matters. I'm glad you guys are doing this.
  - bigiain 6y ago
    While flying, the whole thing is suspended by the motors. It'd only be the weight of the centre components (mostly battery) that'd be flexing the arms. (While crashing, all bets are off. But way back when I used to fly RC gliders they had a saying "If you build them to crash, they won't fly well. If you build them to fly well, they won't crash.") Also, it's not like anyone expects thousands of hours of flight worthiness out of a consumer or even semi-pro drone. Sure the military might spec that for their Predator replacement, but most drone hobbyists I know end up with a bunch of perfectly serviceable old drones which they no longer fly because their gear became obsolete well before the mechanics failed irrepariably.
- asciimike 6y ago
  It flexes in flight (under power load, especially with a battery). The BeagleBone quadcopter we built with plexiglass flexed noticeably. FR4 is better, but it still will flex.
NikolaeVarius 6y ago
I don't really concern PCB drones to be long-term type drones. I have a few, and they're not too bad, as long as you don't fly them full speed at a wall.
yalogin 6y ago
Another? There is one already? Can you please provide info about it?
- hamandcheese 6y ago
  https://www.bitcraze.io/products/crazyflie-2-1/ https://www.bitcraze.io/products/crazyflie-2-1/
  - luminousbees 6y ago
    I agree bitcraze its a great nano drone, but the first version has 3 minutes flight time and it can not be used outdoor, furthermore, Ardupilot is far more advanced and offers a lot more potential and with a huge community of experts, developers and user
    - RealityVoid 6y ago
      UWB is really impressive and I see you have a optical flow positioning add-on board as well. Would like to play around with the current state-of-the-art, curious is fetting things to position indoors got easyer in the last 4 years, since last time I played with it. Something I was thinking recently is using a lighthouse positioning system from Valve for indoor positioning. They have permissive licensing terms and the tech looks very promising: https://partner.steamgames.com/vrlicensing https://partner.steamgames.com/vrlicensing
      - luminousbees 6y ago
        Yes! Lighthouse positioning system from Valve for indoor positioning it's so interesting, swarm compatible, easier to setup, cheaper and higher precision! UWB is our present solution, its already easily in the 10cm accuracy in LOS scenario, it also enables complex indoor space with different connected rooms you want to cover, and you could cover easily 30m between each beacons. We are discussing the option to integrate the optical flow directly into the ArduBee base. If you have suggestions, your contribution is highly appreciated.
contingencies 6y ago
The next step up for rigidity is usually low-cost carbon fiber.
- toss1 6y ago
  True, carbon fiber composites nearly always have greater stiffness and ultimate strength vs fiberglass However, carbon fiber is also electrically conductive, vs fiberglass which is insulating, so that might be just a bit of a problem for a circuit board base... (perhaps solvable, but not the usual near-drop-in upgrade)
  - luminousbees 6y ago
    Yes carbon fiber its an amazing material for lightness and robustness, but we cannot see a way to innovate there with the usual separate parts and its needed cables. ArduBee its without a single wire, ready to fly, apart the motors wires. This in particular for micro drone is really a weakness in terms of flight time and aerodynamics.
luminousbees 6y ago
We use the same design in the big brother for 5" propellers and double the weight of ArduBee. We make this development for our main focus about performative drone for swarm choreographies, its 2 years working with the fleet testing everyday to improve the quality of the performance. We had a lot of crashed indoor, and the pcb never had serious harm. We do not race obviously or high speed onto the wall!
- chrisdalke 6y ago
  That's great to hear that you haven't seen any issues with the PCB design. Thanks for all the great work!

StavrosK 6y ago

Why would the PCB flex? A quadcopter doesn't have that much of a twisting force being applied to it, no?

xtagon 6y ago
Vibration can be a concern with quadcopters especially if the motors and propellers are not properly balanced
- StavrosK 6y ago
  I guess that's true, and they are using brushless motors so you have quite a bit of power there. Hmm.
- luminousbees 6y ago
  Till 1 year ago it has been a great concern, especially for small drone. Now thanks to andyp1per, new Ardupilot dev, we have amazing results with dynamic filtering gyroscope noise, we could even track the mechanical noise peak based on actual RPM or live FFT. Harmonic Notch Filter in Ardupilot https://ardupilot.org/copter/docs/common-imu-notch-filtering.htmlhttps://ardupilot.org/copter/docs/common-imu-notch-filtering.html https://ardupilot.org/copter/docs/common-imu-notch-filtering... new and ongoing development https://github.com/ArduPilot/ardupilot/pull/13121 https://github.com/ArduPilot/ardupilot/pull/13121 https://github.com/ArduPilot/ardupilot/pull/14010 https://github.com/ArduPilot/ardupilot/pull/14010
  - DagAgren 6y ago
    This was about mechanical strain from vibration.
    - luminousbees 6y ago
      You have to consider under the selected IMU, in the center, there is the most of the mass, made by the single 18650 Li-Ion battery. This solution is working, ArduBee is already flying good with the low pass filter in the gyro sets at 110Hz, if vibration would be an issue I guess it cannot fly https://discuss.ardupilot.org/t/ardubee-a-ready-to-fly-micro-drone-for-education-and-swarming/54362/11 https://discuss.ardupilot.org/t/ardubee-a-ready-to-fly-micro...
      - DagAgren 6y ago
        Again, this issue is not the IMU, it's the whole thing breaking mechanically.
roland35 6y ago
Fr4 material is basically fiberglass, and at 1.6mm thick it doesn't take much to bend it if it isn't supported. I think the weight of the motors could be an issue.
- StavrosK 6y ago
  When resting, possibly. In flight, the weight of the battery would probably be the bigger concern, though I think you can get 2mm PCBs.
  - luminousbees 6y ago
    Thanks! this could be a great idea,the 2mm PCB could be an interesting option! We are devoted to 1.6mm PCB since the 5" version that weighs 220g and we haven't had any broken or issue on the PCB piece. The battery is well attached, fixed in 6 well distributed points on the PCB and aligned perfectly in the center of the 4 motors.
    - StavrosK 6y ago
      That's great then, if it works for you that's all that matters. I'm glad you guys are doing this.
- bigiain 6y ago
  While flying, the whole thing is suspended by the motors. It'd only be the weight of the centre components (mostly battery) that'd be flexing the arms. (While crashing, all bets are off. But way back when I used to fly RC gliders they had a saying "If you build them to crash, they won't fly well. If you build them to fly well, they won't crash.") Also, it's not like anyone expects thousands of hours of flight worthiness out of a consumer or even semi-pro drone. Sure the military might spec that for their Predator replacement, but most drone hobbyists I know end up with a bunch of perfectly serviceable old drones which they no longer fly because their gear became obsolete well before the mechanics failed irrepariably.
asciimike 6y ago
It flexes in flight (under power load, especially with a battery). The BeagleBone quadcopter we built with plexiglass flexed noticeably. FR4 is better, but it still will flex.

NikolaeVarius 6y ago

I don't really concern PCB drones to be long-term type drones. I have a few, and they're not too bad, as long as you don't fly them full speed at a wall.

yalogin 6y ago

Another? There is one already? Can you please provide info about it?

hamandcheese 6y ago
https://www.bitcraze.io/products/crazyflie-2-1/ https://www.bitcraze.io/products/crazyflie-2-1/
- luminousbees 6y ago
  I agree bitcraze its a great nano drone, but the first version has 3 minutes flight time and it can not be used outdoor, furthermore, Ardupilot is far more advanced and offers a lot more potential and with a huge community of experts, developers and user
  - RealityVoid 6y ago
    UWB is really impressive and I see you have a optical flow positioning add-on board as well. Would like to play around with the current state-of-the-art, curious is fetting things to position indoors got easyer in the last 4 years, since last time I played with it. Something I was thinking recently is using a lighthouse positioning system from Valve for indoor positioning. They have permissive licensing terms and the tech looks very promising: https://partner.steamgames.com/vrlicensing https://partner.steamgames.com/vrlicensing
    - luminousbees 6y ago
      Yes! Lighthouse positioning system from Valve for indoor positioning it's so interesting, swarm compatible, easier to setup, cheaper and higher precision! UWB is our present solution, its already easily in the 10cm accuracy in LOS scenario, it also enables complex indoor space with different connected rooms you want to cover, and you could cover easily 30m between each beacons. We are discussing the option to integrate the optical flow directly into the ArduBee base. If you have suggestions, your contribution is highly appreciated.

contingencies 6y ago

The next step up for rigidity is usually low-cost carbon fiber.

toss1 6y ago
True, carbon fiber composites nearly always have greater stiffness and ultimate strength vs fiberglass However, carbon fiber is also electrically conductive, vs fiberglass which is insulating, so that might be just a bit of a problem for a circuit board base... (perhaps solvable, but not the usual near-drop-in upgrade)
- luminousbees 6y ago
  Yes carbon fiber its an amazing material for lightness and robustness, but we cannot see a way to innovate there with the usual separate parts and its needed cables. ArduBee its without a single wire, ready to fly, apart the motors wires. This in particular for micro drone is really a weakness in terms of flight time and aerodynamics.

luminousbees 6y ago

We use the same design in the big brother for 5" propellers and double the weight of ArduBee. We make this development for our main focus about performative drone for swarm choreographies, its 2 years working with the fleet testing everyday to improve the quality of the performance. We had a lot of crashed indoor, and the pcb never had serious harm. We do not race obviously or high speed onto the wall!

chrisdalke 6y ago
That's great to hear that you haven't seen any issues with the PCB design. Thanks for all the great work!