Hello everyone, I have posted about this idea before in the form of an aircraft which could transition between vertical and horizontal flight.  While I believe it is possible, especially in the form of a flying wing, the response I have received from this site as well as other sources indicates that most observers have serious doubts.

I have decided to focus on non-transitioning embodiments to eliminate that doubt for now, and hopefully get some feedback on the concept as a purely rotary wing airframe, the helicopter.

What is the point of this weird helicopter?  The goal here is mechanical simplicity, turning a mechanical challenge into a software challenge.  This is why multirotors are so popular.  They are mechanically simple, and the rest is configured and reconfigured with code.  The code can then be copied, altered, provided at little or no cost, and never wears out or needs replacing.  The above concept would require eight moving parts.

This idea would require only three positioning sensors, one for the main shaft, and two for the rotors, and these can be simple rotary position sensors or IMUs which evaluate their position in relation to each other.

I would really appreciate any feedback or ideas anyone might have about this.

Thank You, and Happy Holidays!

Views: 1645


Developer
Comment by davidbuzz on November 22, 2016 at 6:49pm

ideas are cheap.  you need to make one.  just do it.     https://s19n.com/ideas-are-cheap-execution-is-worth-millions-e203ef... 

Comment by Gary McCray on November 22, 2016 at 7:55pm

Hi Joe,

The battery rotating in the fuselage is an intriguing concept, but keep in mind that a large rotating mass like a battery has the negative aspect of resisting motion changes gyroscopically (flywheel effect).

And in this sort of application where the battery would be large and heavy in comparison to the rest of the craft, that effect would likely be very noticeable.

Just a thought to consider.

Another consideration is communication between rotating and non rotating sections of your craft.

Interestingly we are at a time where wireless internal communication of a variety of types could be considered allowing you to have separately powered and wirelessly communicating sections of distributed intelligence.

Best regards,

Gary


Moderator
Comment by Gary Mortimer on November 22, 2016 at 8:52pm

Have a look at tip jets 

Comment by Vladimir Kvitnevskiy on November 22, 2016 at 10:46pm

The mounted brushless motors need power. For that, you could use a slip ring in your shaft, every other idea seems harder to implement. I'd assume they would still be pretty hard to put together for a prototype.

Comment by Rainer K. on November 22, 2016 at 11:27pm

Aerodynamic Natural laws should not be forgotten why so complicated if it is easy

Comment by Mateusz Sadowski on November 23, 2016 at 1:01am

So a bit like a tip jet but not quite? I assume you are still going to use servos to control swashplate? Do you think the rotors on the swashplate will react fast enough to maintain fairly constant RPM when you change the pitch of the main blade?

Comment by Ouroboros on November 23, 2016 at 3:42am

Would concentrating the hardware to essentially a battery rotor hub and joining 2 together (common payload shaft, functionally independent, but one slaved to the other wirelessly) to be a coax be another path?

Comment by Jerry Giant on November 23, 2016 at 3:53am

for a 2m diameter rotor for your design, you will need 2kw from 4 motors at least, and the centrifugal force on the four motors at 2k rpm, do you think it's possible to build such a rotor?

Comment by JB on November 23, 2016 at 6:30am

Hi Joe

It is a interesting layout that will probably hover, but how do you plan to propel it forwards/backwards/sideways with those rotor mounted quad motors that are unlikely to pivot fast enough through differential thrust to provide cyclic control? I'd imagine those motors will get a right workout trying to maintain the correct AoA to maintain level attitude, which in turn will expose the system to significant energy losses. What is your expected main rotor RPM?

What is this platforms intended mission profile? From my perspective this platform looks like a long endurance, nearly stationary VTOL hover platform. There are very few use cases that I can think of for this type of operation.

For long range aircraft, or for long endurance aircraft, a spinning wing (heli) can never compete with a fixed wing, simply because the "wing" only has an optimal angle to produce lift in the direction of travel (airflow) for a fraction of its rotation angle. A heli, is essentially artificially creating a moving wing by spinning it about an axis, that in itself is never optimal for any direction of travel, as it needs to return to it's point of origin to complete it's rotation. In contrast a fixed wing always travels in the direction of travel and can be optimised accordingly. Put another way, the heli "wing" needs to travel significantly further through the air than a a fixed wing would to lift the same weight, and even backwards for half of the time, yet the usable fuselage part of the airframe travels the same distance in both. 

Considering this, I'd expect an airframe for range and endurance to be configured in such a way so that the wing/propulsion setup is optimised for the required cruise in forward flight, and reduce the fairly short period of VTOL flight into a secondary, much less dominate role. For example to make a plane VTOL adding a small quad setup for short period VTOL components of flight, like in a quadplane, would be most effective IMHO.

Regards JB

Comment by Chris Cloutier on November 23, 2016 at 7:36am

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