Need help building a large quadcopter

[mozquito1]

It starts getting dangerous when you're putting gears & chains onto the motor.
You go try buying such thing as pinion gears for what you need. These will be proper aviation grade materials & that's just a gear. You're on the wrong site.
You need mechanical engineering skills if going fuel. I would hate to try & give advice only to hear a man was decapitated on the news.
how do you the independent speed of each motor for direction. Going to need some sort of esc.
Sorry that's all I've got.

 

[mozquito1]

So your using fuel that then needs to be converted into DC for power of some sort of esc & on board electrics.
So that's on board fuel aswell as batteries.
You may as well just go all out Batteries & save the weight of an empty or full fuel tank. Less moving parts the better for maintenance & safety.

 

[wafflejock]

While I agree on the do it safely part of your comments I don't think this is necessarily not worth exploring if one has the money, the will, and the brain to make it happen. The guy working on the 'drone generator' has made incremental steps to improve his design attempting to eliminate extra forces and vibrations from the generator and make it compact enough to put on a large quadcopter for extended missions. Search and rescue for example, it's something that was touted as a great use case for quadcopters but with battery powered flight you are pretty limited on range....iirc gas fuel is something like 100 times the energy density. Don't get me wrong I agree on more moving parts is more likely to fail and chances of failure when leaving into the unknown is high, but so long as it is done safely I don't see any reason not to experiment.

 

[LoneRCRanger]

Instead of spending a bazillion dollars on a project that probably isn't going to do anything more than kill you on its first crash, just buy something that is a proven platform, like a Helicopter!

 

[wafflejock]

Instead of spending a bazillion dollars on a project that probably isn't going to do anything more than kill you on its first crash, just buy something that is a proven platform, like a Helicopter!

I built my own esk8 and designed and made my own controller/transmitter and receiver for it since the off the shelf options were either over priced or not great for the use case. Why all the naysaying, very likely the project literally doesn't get off the ground, but I don't see harm in experimenting so long as the experiments are done safely. With my controller and esk8 in general I did a lot of bench testing and had to debug and learn about power transfer through belts and why idler bearings/pulleys help. I would have saved time buying off the shelf solutions but would have missed out on learning or being able to innovate.

While this project is way outside the scope of things people do on this forum and the OP is likely going to need to seek help from elsewhere I haven't seen enough to say it just won't work or has no merit.

 

[mozquito1]

Sorry but wile e cayote springs to mind

Get yourself insured.

 

[mozquito1]

Like you say bearings & belts or chains gears. You fall just 25ft in some contraption, your toast. I'm not nay saying, just he is in the wrong forum & how expensive & dangerous this could be. If I had stupid money to throw at it I'd probably start with some
emax 22000 75kg thrust
1.21 jiggawatt esc's
Airwolf F16 flight controller
Blue thunder backup system
Tomahawk cruise missile party poppers
Tesla graphene 700,000mah 28S 1570C
Pop out trampoline safety system
& some rotor riot stickers