Hello all,

I’m new to this.  I’m in the medical field, and I need a hobby.  So I decided to build a drone.  A big drone.  I’m going to build an octocopter that can carry me.  If you have some suggestions, please let me know.

This size machine has been built and is working toward commercial operation.  I’m just looking for one I can call an experimental and fly in it on clear days.  The SureFly has been my inspiration.  It looks as if they are using a BMW range extender engine to power the system as a hybrid machine.  The SureFly also has a small battery pack that gives the craft 5 min of flying time if there is an engine failure.  They want to sell this for about 200K.  I can’t afford that, besides, it would be more fun to build it.

As I work to learn more about this, I recognize that I have multiple knowledge deficits.  My hope is that I can come to this forum and ask some questions.  I’m not looking for you to do the math for me, but perhaps give insight on where to go to learn specific skills sets and areas of knowledge.

For example, I’m uncertain of the amount of power I need to operate the motors.  I’m looking at the highest powered brushless motors I can find and I can see multiple energy specifications listed.  But I’m not certain which translates into determining the max power I need for 8 motors on this machine.  The range extender engine provides 25 kW.  I need to better understand how to make this calculations and how to convert the power from the range extender to the motors without blowing out any electronics.  As I said, I’m not looking for anyone to do my math, just perhaps direct me to an area where I can learn what I need to know.  Specifically, which specification listed on motors will provide me with the numbers I need to know to calculate if I have enough power with the BMW motor.  I suspect that if SureFly can power with the BMW motor, I should be able to do the same.

Furthermore, while I am looking at numerous brushless motors, does anyone have any suggestions for which brushless motors might be the best for this project? 

I’m certain I will have many other questions.  I appreciate any assistance and moral support I can obtain.

 

Views: 270

Reply to This

Replies to This Discussion

Well i love this discussions, so you want to kind of do a copy of http://www.ehang.com/ehang184/

that can fly about an hour , and it is fully electric.

First of all, you need to calculate your thrust, that in your case is the sum of the thrust of all your motors at the 50% of throttle.

In function of that you will need a motor with a specific power, constant velocity (kv) and a specific proprler dimension
you can see this video very clear about propellers:

https://www.youtube.com/watch?v=jBt4iZcPTt4&t=1s

even i think you can use the same motors as this guy:
https://youtu.be/L-iWUu2HAWQ?t=376

You need to design all the connections to be secure-failsafe,
the ESC need to be designed to handle twice the max power yo will ned for the motor,
the signal wires need to be coaxial wires and with double connections, remember if you are going to fly in it you need to duplicate al the systems

The thing is the main computer onboard yo will use , and the software.
i think one of the best optios is Ardupilot Copter versions, first:
1 do it yourself a small low cost(400$ in total) drone with Pixhawk 2.4.8 just to experiment and get experience with the user interface,
2 wen you know woh this plataform rorks, (probably will take you like 3 months) you are redy to start to build the big one
3 buy a god an original pixhawk flight controller from mrobotics for example
4 buy the brusles motors the esc the flight controller, the bateries and a RC controller from futaba for example (a god one)
4.1the batery you will ned ned to have the capacity for making work all the motors and more you cand found more information about the batery you
will ned on the internet but basicaly if you use lippo bateryes, you will ned to arrange then in series-paralell to get enought voltage and amperes per houir
if you have for example 8 motors that requires 500 Amperes to put them on full throthe, you will ned a batery that can suply at least
700 Amperes in the maximum discharge close to shortcircut y

me?
you can learn more about bateries on the internet and doing your first small low cost drone.

5 you will notice that when you are driving a drone you use a RC controller, well if you are inside a big drone, the way you controll the drone dont require a use of a RC controller but even that you can use it ,
you understand me?
you can easy change that by change the RC receiver for a PWM or PPM generator but that will be at the very end...
in that situation you no longer need a RC transmiter to control you aircraft.


finally before you fly the firs time any multicopter, you will need to perform a PID adjust to have a correct actitude of the motions of your drone
you will learn much more about that wen you do your first small low cost drone, and if you chose Ardupilot, it has an Autotune option, that is like magic...
well nothin more to say at this point, my mi final advice is that you van put an emergency parachute on it aswell ;)
if you are motivated to start this you will learn a lot of for sure

pd.:
and yes, for those extras who read this, i think is perfectly possible to build such a thing from a user perspective

Wowy! Have you ever flown a drone before? 

I would as a first step fly and build something very small as this is a very complicated and dangerous project! But I am excited to see what you make.  

Thanks so much for all of the input.  There is so much to learn, but I'm having fun doing it.  When I actually start building, I will post the details and photos.  Right now, my first step is building a small quad-copter.  I started that last week.  Figuring the power system, using a hybrid engine continues to challenge me.

Rene

Alberto Vila said:

Well i love this discussions, so you want to kind of do a copy of http://www.ehang.com/ehang184/

that can fly about an hour , and it is fully electric.

First of all, you need to calculate your thrust, that in your case is the sum of the thrust of all your motors at the 50% of throttle.

In function of that you will need a motor with a specific power, constant velocity (kv) and a specific proprler dimension
you can see this video very clear about propellers:

https://www.youtube.com/watch?v=jBt4iZcPTt4&t=1s

even i think you can use the same motors as this guy:
https://youtu.be/L-iWUu2HAWQ?t=376

You need to design all the connections to be secure-failsafe,
the ESC need to be designed to handle twice the max power yo will ned for the motor,
the signal wires need to be coaxial wires and with double connections, remember if you are going to fly in it you need to duplicate al the systems

The thing is the main computer onboard yo will use , and the software.
i think one of the best optios is Ardupilot Copter versions, first:
1 do it yourself a small low cost(400$ in total) drone with Pixhawk 2.4.8 just to experiment and get experience with the user interface,
2 wen you know woh this plataform rorks, (probably will take you like 3 months) you are redy to start to build the big one
3 buy a god an original pixhawk flight controller from mrobotics for example
4 buy the brusles motors the esc the flight controller, the bateries and a RC controller from futaba for example (a god one)
4.1the batery you will ned ned to have the capacity for making work all the motors and more you cand found more information about the batery you
will ned on the internet but basicaly if you use lippo bateryes, you will ned to arrange then in series-paralell to get enought voltage and amperes per houir
if you have for example 8 motors that requires 500 Amperes to put them on full throthe, you will ned a batery that can suply at least
700 Amperes in the maximum discharge close to shortcircut y

me?
you can learn more about bateries on the internet and doing your first small low cost drone.

5 you will notice that when you are driving a drone you use a RC controller, well if you are inside a big drone, the way you controll the drone dont require a use of a RC controller but even that you can use it ,
you understand me?
you can easy change that by change the RC receiver for a PWM or PPM generator but that will be at the very end...
in that situation you no longer need a RC transmiter to control you aircraft.


finally before you fly the firs time any multicopter, you will need to perform a PID adjust to have a correct actitude of the motions of your drone
you will learn much more about that wen you do your first small low cost drone, and if you chose Ardupilot, it has an Autotune option, that is like magic...
well nothin more to say at this point, my mi final advice is that you van put an emergency parachute on it aswell ;)
if you are motivated to start this you will learn a lot of for sure

pd.:
and yes, for those extras who read this, i think is perfectly possible to build such a thing from a user perspective

I played with one a while back, but nothing more than a toy.  I'm building a quad-copter from a kit right now and learning about the components.  But making it on the larger scale, that seems to be the challenge.

Tristan Semmelhack said:

Wowy! Have you ever flown a drone before? 

I would as a first step fly and build something very small as this is a very complicated and dangerous project! But I am excited to see what you make.  

For those of you who are following this discussion, here is a critical piece of information I received today.

"The 10218 with 30.5” triple props is capable of lifting 57.28 pounds at full throttle on a 53.8V input and draws 6.2kW per motor. The 10218 with 30.5 double props can lift 53.09 pounds at full power (on 53.8V), but only draws 4.7kW.

The total lifting power of these motors and propellers is 424lbs and 458lbs for the double and triples respectively. Total power consumption for both set-ups is 37.6kW and 49.6kW." 

www.KDEDirect.com

Right now, I'm looking for the power source.  I was starting my search with the BMW W20 REx Engine.  It looks like it only makes 23.3 kW.  I will need 2 engines or a different power source..

The search continues....

why you ned a combustion engiene? if you are thinking about a hybrid system i would advice to you watch this video:

https://www.youtube.com/watch?v=1yB49G756OI

and this:

https://www.youtube.com/watch?v=7zMPodObo-Y

But, this drone

Image result for ehang

It is completely electric, 
a combustion engine could add more autonomy, but increase the weight ....
Look at this :
Image result for ehang 184 battery pack

I like the ability to have a longer flight time with an engine as well as the ability to refuel and return to flight.  Besides, finding that correct balance between engine and lift is a challenging concept.  Last night I was looking at microturbine auxiliary power units as well as used aircraft APUs.  This will be an interesting build.

Alberto Vila said:

why you ned a combustion engiene? if you are thinking about a hybrid system i would advice to you watch this video:

https://www.youtube.com/watch?v=1yB49G756OI

and this:

https://www.youtube.com/watch?v=7zMPodObo-Y

But, this drone

Image result for ehang

It is completely electric, 
a combustion engine could add more autonomy, but increase the weight ....
Look at this :
Image result for ehang 184 battery pack

also able to special order 15-20kw hydrogen fuel cell kits with hiy pressure tank alternative to a petrol generator can be much lighter solution for a range extender.  

also able to special order 15-20kw hydrogen fuel cell kits with hiy pressure tank alternative to a petrol generator can be much lighter solution for a range extender.  

Reply to Discussion

RSS

Groups

Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Vertical Horizontal one, is here

© 2019   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service