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28 minutes flight time ! 3" sub 250 Arducopter

Research and build for a sub 250 drone capable of running Ardupilot in all of its functions (including autnomous flight) to maximize flight time.

Weight minimization is key to maximize flight endurance. Batteries represent the bigger % of total weight in such a build. In order to stay below the 250 grams limit (thank you @!_* regulators), 2S voltage is practically a constraint. Therefore research has to be invested in ESCs and flight controllers able to operate under such small voltage. Li-Ion appears to be the current only battery having the best capacity/weight ratio to build a lightweight 2S battery.

Then comes the frame optimization. Most drone frames are overbuilt on purpose in a hype to resist hypothetical circumstances that never happen or are simply unrealistic. Therefore there is a huge oportunity in researching frame design improvements that minimize weight while still maintaining enough rigidity and solidity.

Frame used in this video comes as a result of many hours and discussions in our private international research group of experts. In particular I would like to thank and put Ryan forward (see quadstardrones) who holds the current worldwide record of designing and making the fastest racer drones.

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Great Design work! Thanks for listing the component’s as I know finding 2 cell gear is tough. Any chance of getting files for the 3D printed parts?

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What a build! Love it!

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Great design!
I am also in the way of building a small sub 250 Arducopter.
I am working on topology optimization to build a light and rigid frame.
I have done the first steps and I think it is feasible, but I would need a much faster computer to make a serious job.
I will share my results when the design takes form.

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Have you looked into VESC and Field Oriented Control? That should net an even more impressive increase of flight time over what you’ve already managed.

interesting. To investigate…

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If VESC/FOC are not possible, as an interim step, many people in the BLHeli/microquad crowd have seen some impressive gains in flight efficiency by stepping up from 24kHz PWM signaling to 48kHz PWM signaling (96kHz PWM signaling apparently represents a significant drop in value proposition, giving marginal gains in efficiency at a greater loss of control authority).

That might also be something to A/B test with your current setup.

In conversation with a member of the community, they gave a report that a sUAS with (proprietary) FOC ESCs and a 4s 5800mAh battery pack flew in excess of 40min.

May you find something interesting…

https://vesc-project.com/

I’d like to see some evidence of that long of a flight time. Did they publish anything about it ?

Went quickly on the VESC web site but I can’t find an overview nor explanation of the goal or more simply what it is about? It assumes visitors know it. Also tried the “inventor’s” personal web site (vedder.se) it is a listg of blogs since 2012 and not very clear.

They were referencing the Lockheed Martin Indago series of sUAS, but didn’t mention what generation or configuration in specific.

See this blog post on the VESC creator’s website for an overview and links to everything:
http://vedder.se/2015/01/vesc-open-source-esc/

Thanks for this link. That explains his bill of material, PCB and electronic schematics but it does not explain at all what his objectives/purpose and principles are in his motor control approach. It relies on what algorithm, what physical principles? what is it he tries to achieve better than the existing ESCs? In short what problems or improvements is he trying to achieve ??
Doesn’t he reinvent the wheel ?

Vector Control, or Field Oriented Control is the driving principle behind his VESC implementation. It wasn’t attainable due to various constraints until just recently.

It’s not re-inventing the wheel so much as a change in how efficient wheels are. Like going from a stone wheel to a modern LRR high efficiency tire.

https://www.digikey.com/en/articles/techzone/2011/oct/increasing-motor-performance-with-field-oriented-control

https://www.eetimes.com/implementing-field-oriented-control-of-a-brushless-dc-motor/

There are other papers as well, but some get beyond me quite quickly.

Interesting. Some reading to do

Beau travail Hugues !
Mais franchement avec les nouvelles règles qui obligent à se tourner vers les 250 gr je ne vois plus beaucoup d’interet dans les drones.
Si on ajoute la camera il faut réduire la batterie et donc l’autonomie de vol et alors seul les grosses entreprises comme DJI peuvent faire des projects ciblés où investir un paquet d’argent pour plus d’intégration des composants.
C’est une bataille perdu d’avance pour nous les petits…

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merci Luca. Je comprends ton point de vue.Mais justement cela va booster la creativité et les recherches pour se libérer de ces contraintes régulatoires. Il faut se battre !

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