weight limitations

Discussions and questions about the Crazyflie Nano Quadcopter
Post Reply
Newbie
Beginner
Posts: 12
Joined: Sun Oct 31, 2021 8:30 pm

weight limitations

Post by Newbie »

Hi, I am trying to make an autonomous drone to carry a small sensor on its back. For the autonomy part I got the flowdeck and the multi ranger deck. I am thinking about adding the AI deck too. But to store data I will also need the micro SD card deck, and to carry the sensor I will need to add the prototyping deck.

Obvious question: can the quad still lift with all of this load? Can the batteries charge all of this or will it stop after 3 minutes? What would the limits be?

Any help would be appreciated, thx!
kimberly
Bitcraze
Posts: 1050
Joined: Fri Jul 06, 2018 11:13 am

Re: weight limitations

Post by kimberly »

The absolute maximum the crazyflie can carry is 15 grams, and that is just in pure weight. The flowdeck+multiranger+ aideck+sdcard alone is already 10 gr, so the prototype deck with the extra sensor should be extremely light.

Also you need realize that those deck take up energy as well, which takes away more of the batteries effective capacity. You can find each decks consumption here: https://www.bitcraze.io/documentation/s ... #deck-info

So currently you would like the crazyflie to carry 5 decks, which is actually even with the long pins not possible. Either you have to sacrifice some decks, or you build a custom frame with the crazyflie bolt: https://www.bitcraze.io/products/crazyflie-bolt/
Newbie
Beginner
Posts: 12
Joined: Sun Oct 31, 2021 8:30 pm

Re: weight limitations

Post by Newbie »

Thanks Kimberly,

Right now I have one deck under the crazyflie (flowdeck), and I have one on top (rangefinder deck) for the autonomy, but I need at least the SDcard deck and then the prototype deck on top with the sensor.....so 4 decks in all. I saw the perfect crazyflie adaptation done by students from Washington University, it even had the sensor I needed. The only thing they did not add was the AI, and I do not think they had the SD deck either. I have downloaded their page with the info, but I will also check out the energy consumption and start looking at the Crazyfly Bolt.

My planned flight time is about 4 minutes max...perhaps even 3 (speed of scanning a room), so I do not expect too many problems with this. I think I should also start looking at the option to connect the crazyfle decks to a different frame with more powerful engines...? Although I am not sure if the power required for this (I am thinking two batteries), will fry the crazyflie PCB......well I can always buy a new crazyflie and try again.
tobias
Bitcraze
Posts: 2339
Joined: Mon Jan 28, 2013 7:17 pm
Location: Sweden

Re: weight limitations

Post by tobias »

The get a higher lift capability you can switch to 7x20 motors, 55mm propeller and a bigger battery. Search the forum for "7x20" and you will get at least some information on how to do it.
Newbie
Beginner
Posts: 12
Joined: Sun Oct 31, 2021 8:30 pm

Re: weight limitations

Post by Newbie »

Thanks Tobias,

Will check it out!
kimberly
Bitcraze
Posts: 1050
Joined: Fri Jul 06, 2018 11:13 am

Re: weight limitations

Post by kimberly »

Yes, although I'm not sure if the Washington crowd use the multiranger though, but indeed if you do what tobias said and get a better lift capacity, then it will be able to carry it. The only thing that is remaining now is to connect the fourth deck to the crazyflie, which might be tight... but you could consider using the pads on the side connector of the multiranger or sd card deck and add the sensors directly on there? I've done that before where I connected an sd card camera directly (for power only) to the multiranger deck's pad and glued it directly on that deck, but just be aware that all warranty is voided on that one deck if you do.

Good luck!
Newbie
Beginner
Posts: 12
Joined: Sun Oct 31, 2021 8:30 pm

Re: weight limitations

Post by Newbie »

Thanks Kimberly for the tips. I dont mind about the warrenty, I really want to experiment, and I will buy a new one if I damage my current Crazyflie.

I looked again at the Washington Crazyflie, and they used the multi-ranger and flow deck, but not the AI. I calculated the weight of everything including the sensor, and the total weight of all the decks and my sensor is 12.6 grams, so I don´t think I will need stronger engines.

But as you mentioned earlier, so many decks is hard to connect. May i ask if there is a reason why you cannot use even longer male deck connectors? Like long enough to connect three decks on top?
kimberly
Bitcraze
Posts: 1050
Joined: Fri Jul 06, 2018 11:13 am

Re: weight limitations

Post by kimberly »

The pins are long enough to support 3 decks, but 4 decks might be too tight. But I guess that a bit of soldering a smaller pinheadsers on the long pinheaders it can connect to more. I'm sure you'll be able to find a nice solution for this.
Newbie
Beginner
Posts: 12
Joined: Sun Oct 31, 2021 8:30 pm

Re: weight limitations

Post by Newbie »

Thanks for the tip again. And thanks for your patience. I am already looking at some solutions :)
Post Reply