New to Helicopter Drones

[Chan117]

Hi,

There seems to be a lot of information out there for Quadcopters, but I've taken an interest in Helicopter/Single-Rotor Drones but am quite new to the whole design/build process of them.

Would anyone have any pointers and/or advice for building a Heli-Drone with a payload capacity of 5Kg for example. How do I go about specifying the right components and what calculations do I need to determine the type of airframe required, and what motor is best with propellers etc.

Any advice and/or information would be greatly appreciated.

[xviper]

I've never heard the term "helicopter drone" till now. Is this something new? What are they? I only know of RC helicopters in different categories - coaxial, fixed pitch, cyclic pitch. You might get more specific help if you clarify which one you're referring to.
"Quadcopters", to me, are 4 motor/prop multicopters - hence "quad". Then there are tricopters, hexacopters and octocopters and so on. Drones can be any unmanned, remotely controlled aircraft.
PS. A guy local to me built an octocopter that could lift and carry a 12 pack case of beer. I've also seen YouTube videos of someone who had 2 CP helicopters that could lift an adult human.

[Chan117]

I'm interested in learning more about RC Coaxial Helicopters and how exactly to specify components. For example, if I wanted to lift a payload of 2.5-5kg (camera equipment)for at least 60 minutes, then what components should I be looking for?

I understand this may be a broad question but I'm hoping to narrow it down as I learn more.

[F106DeltaDart]

I'm interested in learning more about RC Coaxial Helicopters and how exactly to specify components. For example, if I wanted to lift a payload of 2.5-5kg (camera equipment)for at least 60 minutes, then what components should I be looking for?

I understand this may be a broad question but I'm hoping to narrow it down as I learn more.

I'm not sure if I can adequately convey the difficulty and expense of what you are trying to do. Motor/Rotor selection is not nearly as straightforward as on a multirotor. Its also going to take lots of manual flying and gain tuning to get it dialed in and flying as an autonomous platform.

A Coaxial platform is a very poor choice for a long endurance mission first off. Coaxials are good for lift work, but they are complex and heavy. A single larger diameter main rotor will give higher hover efficiency and longer flight time for less complexity. More or less, you seem to be looking for this... : https://www.anduril.com/hardware/ghost-autonomous-suas/

Do you have any helicopter experience? I'm guessing not by your questions. Does it need to the electric powered or is gas an option?

As for component selection, components are generally sized to target a desired rotor RPM from experience. For example, a scale 800 heli might run around 900-1100RPM. The tail rotor is typically geared to rotate at 4-5 times the main rotor RPM. Higher voltage is generally desirable for longer flight times and higher loads. 12S is the standard for a 700-800 size heli. Servos are primarily sized through experience, and are picked conservatively. Collective pitch for a scale aircraft is generally set around -3 to 12 deg, with some variation. ESC size is also sized conservatively, and is heavily dependent on the desired mission and flying style.

This probably isn't what you were looking for, but there is a ton that goes into it. If you REALLY want to pursue this, I recommend getting a beginer heli (Blade 230 or similar) and learning to fly. Move up to a kit after that, something in the 420-600 range. Once you are comfortable there, maybe a 700-800 with some serious modifications could be made to accomplish your mission.

[xviper]

I agree with everything F106 said. Making an RC coaxial helicopter capable of lifting 10 lbs for 60 minutes is a HUGE ask. It's going to take a very large machine that can not only lift what you want but must also hold and lift enough batteries to fly that long. Typically, RC coaxial helicopters are basically "toys" and are small and those generally can only fly for a few minutes.

You are essentially looking to build a scaled down version of a machine like this:

https://siamagazin.com/huge-rc-kamov-ka-26-coaxial-electric-model-transport-helicopter/

These things can run you into 10's thousands of dollars. Unless you have immense resources available to you, building one from scratch will be very difficult.

Here's one .......... https://www.youtube.com/watch?v=q5K8DgKmVEk
But it's not a coaxial. However, you might be better off to target a CP helicopter with full gyro stabilization. Otherwise, they are very hard to learn to fly. CP helis can lift a lot of weight without having to get too big but flight time will be a limiting factor.

A multi-rotor might be a better choice. Even there, 1hr flight time is going to be tough.

You might start by reading stuff like this:

https://www.helifreak.com/showthread.php?t=780409

[Chan117]

Thank you guys for the information and pointers. Greatly appreciated.

[xviper]

Those things from Avatar are NOT coaxial helicopters. They are called "Aerospatiale SA 2 Samson Utility Helicopter" and are fictional machines. A couple of companies have tried to manufacture little toy ones but they don't fly well and they don't sell well. I call them "tandem" helicopters.
Here is one example of a custom made one: https://www.flitetest.com/articles/a...-sa-2-bicopter
It flies for 3 minutes and won't lift anything more than its own weight.
The closest thing to these sorts of model aircraft is the V-22 Osprey. I've had several and they do not fly well. You need a very sophisticated flight controller and these companies can't sell them if they put such a device into them. The flight controllers they put into them are primitive. Anyone trying to build one must have the skills to develop a flight controller or be able to program an existing one. It is nearly impossible to fly one without a flight controller.

[fredmdbud]

"Tandem" indicates "one in front of the other" (e.g. CH-47 Chinook) - the SA 2 can generally be described as a tilting "bicopter", or more specifically a "wingtip-rotor".

But yes, co-axial is a different type (the co- referring to sets of rotors sharing the same axis of rotation).

[xviper]

A V-22 Osprey can be called a "transverse" rotor system just like the fictional Avatar machine. This type of system can also be called a "side by side tandem" system. "Tandem" can mean one in front of the other or side by side, just like side by side tandem bikes, or trikes or quadracycles.
But Fred, you just love to argue, so this is the end of it for me. You have fun arguing with yourself and being obnoxious to others as in the "What's next Alpha" thread. The ignore list IS the best place for you.

[fredmdbud]

You used tandem to mean side-by-side. It means front-back. Not argument, but facts - check the dictionary. If you have a problem with a correction, well, that is indeed your problem. Heck, you yourself corrected someone!