Hybrid multi-rotor , gas engine for lift and electric motors for control

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khaled_abobakr

Member
Hi

Please correct me in order to build a hybrid multi-rotor like the one in this video, assume I will use a Naza .. this means I will NOT connect the throttle channel from the receiver to the NAZA throttle input .. but directly to the throttle servo .. This is to save the electric power of the electric motors for only controlling (Pitch, Roll, and Yaw) but not for thrust, so when I move the throttle stick , only the Gas engine will increase the RPM.

Any help is greatly appreciated

Thanks
Khaled
 

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tombrown1

Member
Seems like the NAZA would get pretty confused. You may need to hack it. Ambitious project. You trying to film with this? The gas would give quite a few vibrations I would think.
 

R

R_Lefebvre

Arducopter Developer
This could be done easily with Arducopter. If anybody eve needs to develop custom control code for machines like this, I'm available on contract.
 

Old Man

Old Man

Active Member
I was wondering how you worked. Thanks for the enlightenment:) We should touch bases soon.
 

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bruce365

Null
Next step would be to connect an altinator to the gas engine and do away with the limitation of a battery altogether. great prototype.
regards - bruce
P.S. gas powered helicopter would make more sense or not?
 

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Scott Drysdale

Mixmaster
:tennis:Make more sense? Yes..... most liquid fuels have a vastly superior energy density over any battery electrochemistry and there is less dead weight being carried with liquid power as the fuel level goes down.
Highest energy density fuel is kerosene followed by diesel, then gasoline and finally methanol near the bottom.... although additives such as nitro spike it back up sharply.

But the downside is that exhaust residue, especially the lubricant tends to spread around and would quickly foul up the any video camera lens etc.
Also there is the added complexity that remains the primary enemy of system reliability.
I would opt for a wankel engine due to its superior thrust to weight ratio then add a dc generator to keep the batteries charged for 6 not 4 MR electric motors for 3D orientation etc.
The wankel would simply be used to nullify the total AUW while the remaining electric motors would do all the rest.
This means the MR electric throttle would run thru the WooKong or NAZA while a separate channel and/or radio would be used to throttle the Wankel but only for neutral buoyancy as previously stated.

It is a great idea IMHO!!!!
 

K

khaled_abobakr

Member
Thanks a lot for the inputs gents ..

Could you please tell me what you mean by MR ??


I'm researching this idea for a long endurance .. but then again ... like a gent just said a large gas heli will do just fine

Khaled
 

Old Man

Old Man

Active Member
Before this thread goes any further I'd like to know the nationality and physical location of the OP, along with political and or religious affiliations. Those matter quite a lot any more I'm sorry to say. The subject matter of this thread is bouncing heavily on subjects that are controlled when in combination under International Trade and Arms (ITAR) regulations. Some U.S. based companies have been working with solutions for this dilemma and although open sharing of information is indeed helpful, it could end up quite harmful when given freely to some entities. Yes, I know that technology is a genie that once out of the bottle frequently belongs to any that can make use of it but some bottles should never be "uncorked" in front of unknown company. I'm quite familiar with all the aspects of the OP's inquiries and know well what is currently in play at some locations.

I fully expect some to lambast me for my position on this but as one that has worked in research and development for the last 10 years I'm quite sensitive to the dumping of some information on the internet where nobody knows who the recipient of the information is, does not know their affiliations with any organizations, and are unaware if such information is to be used for peaceful or commercial application or as a tool in warfare against people we profess to be allies with. In this case the OP is not cognizant of what the abbreviation MR stands for, which seems a bit odd considering where they are seeking advice. Sorry to be so blunt but there are times a desire to help ends up generating more problems than people considered. I apologize to the OP if intentions were peaceful and pure but there's no way for me, or anyone else, to know that based upon what has been published thus far in this thread.
 

K

khaled_abobakr

Member
I completely understand ... and I agree with you

Old Man said:
Before this thread goes any further I'd like to know the nationality and physical location of the OP, along with political and or religious affiliations. Those matter quite a lot any more I'm sorry to say. The subject matter of this thread is bouncing heavily on subjects that are controlled when in combination under International Trade and Arms (ITAR) regulations. Some U.S. based companies have been working with solutions for this dilemma and although open sharing of information is indeed helpful, it could end up quite harmful when given freely to some entities. Yes, I know that technology is a genie that once out of the bottle frequently belongs to any that can make use of it but some bottles should never be "uncorked" in front of unknown company. I'm quite familiar with all the aspects of the OP's inquiries and know well what is currently in play at some locations.

I fully expect some to lambast me for my position on this but as one that has worked in research and development for the last 10 years I'm quite sensitive to the dumping of some information on the internet where nobody knows who the recipient of the information is, does not know their affiliations with any organizations, and are unaware if such information is to be used for peaceful or commercial application or as a tool in warfare against people we profess to be allies with. In this case the OP is not cognizant of what the abbreviation MR stands for, which seems a bit odd considering where they are seeking advice. Sorry to be so blunt but there are times a desire to help ends up generating more problems than people considered. I apologize to the OP if intentions were peaceful and pure but there's no way for me, or anyone else, to know that based upon what has been published thus far in this thread.
Click to expand...

Hi Old Man

I completely understand ... and I agree with you .. and I apologize for not introducing myself before asking such questions .. 1st of all my forum name is my real name over all the forums I'm registered in .. although some do not recommend that but frankly I have nothing to hide .. except that I'm starting to be ashamed of myself since the recent events .. now I truly want to change my name, religion and my nationality because some that have names, and religions like I do do horrible things that I definitely don't agree with .. I've been doing R/C for more than 8 years now .. mainly as a hobby and recently as a team member participating in drones for good contest held by United Arab of emirates .. UAE dronesforgood.ae search for my name over *** .. fpvlab.com, helifreak.com ... also a regular customer at readymaderc... and many other online hobby shops

my intention was to investigate this concept and to make use of it if it proves that it has advantages over similar aircarfts

MR ... could be main rotor .. .. but frankly I needed that gent to explain what he exactly meant .. because it could be something else ..

Now back to myself

I'm a Muslim, Sunni, Egyptian , has a bachelor degree in mechanical engineering ... 37 years old, currently working in UAE for that contest , and respect humanity and the differences God created between us , even if some don't believe in him .. I have learnt all what I know in R/C from gents from all countries in the globe, and I'm proud to say so .. some of them are atheists , Christians, maybe other religions I don't know of ... and that never held me form enjoying our conversations about R/C .. and we have mutual trust ,, and have made so many deals with them ... I have bought and sold so many items over the internet .. check my trader rating in ***...

I respect you all and respect our differences .. and I do love to exchange info in this hobby .. give what I've learnt in the past to a new comer .. I was in his place before , and I'm still and will always be a new comer in all the new fields that I don't know of .. so I'm always learning and also giving what I learnt .. returning the favor :)

I really appreciate your concern .. and you are absolutely right .. you done the right thing and in these days everyone should do the same

Have a great day
Khaled
 

Old Man

Old Man

Active Member
Thank you for being forthright. I should clarify that religion in and of itself should not matter, just how it is leveraged. I've spent considerable time in your general area of the world and found most people are the same as anywhere else and want the same things. To be safe, have a full stomach, watch their children grow up safely and be successful, to live a full and healthy life. Generally for all to be happy. People across the world are generally the same in most things. That was from the heart. Enough of the political stuff.

Having considerable experience with what you are seeking to do, but also being a bit careful with what I say, the concept can be done but not on a small scale due to losses of efficiency as one mode crosses to the next, and due to fuel reservoir sizing and weight of the combustion power unit. None of that factors vibration isolation, which is a significant item with any reciprocating combustion engine. The Wankel idea was a good one but unfortunately doesn't work out that well in practice unless significant changes are made to the rotary engine design. A turbine would be better still but fuel consumption prohibits their use. Fuels used are another issue in and of itself. Methanol based fuels are consumed too quickly because it requires more fuel to make more power and diesel fuels, when used in a true diesel, require a massive case construction to contain the compression/combustion impulse. The overall concept works but even a 1200mm multirotor is not large enough to make efficient use of the combustion/electric hybrid concept. In sizing downwards one ends up back where they started with heavy, very limited flight time aircraft. It takes power to make power and unfortunately you have a 12% to 25% loss of efficiency as things transition. Making that worse is that although the energy density of liquid fuels is quite high the actual efficiency of combustion engines is quite low. On the order of 30% efficiency or less (generally less) in most cases, which become less still as altitude increases with a normally aspirated engine. The concept is a very tough balance between a lot of different component features that are not normally related that closely

I wish you the best of luck!
 
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S

Scott Drysdale

Mixmaster
Khaled...... MR stands for Multi-rotor. AUW = All Up Weight. R_Lebfebvre has some give classroom video instructions on the disc area concept as it relates to MRs and conventional rotorcraft.
Methanol/nitro fuel to drive a single rotor heli might still be the best choice for long duration aerial video work provided that system stability matches or exceeds that of MRs.
But the mechanical complexity and maintenance of single rotor seems to be the constraint causing the big shift towards MRs.

Me..... I am holding out for a newer power system for MRs using a Tokamak nuclear fusion reactor to drive an onboard electric generator. ;-)
http://en.wikipedia.org/wiki/Tokamak_Fusion_Test_Reactor
 

K

khaled_abobakr

Member
Scott Drysdale said:
Khaled...... MR stands for Multi-rotor. AUW = All Up Weight. R_Lebfebvre has some give classroom video instructions on the disc area concept as it relates to MRs and conventional rotorcraft.
Methanol/nitro fuel to drive a single rotor heli might still be the best choice for long duration aerial video work provided that system stability matches or exceeds that of MRs.
But the mechanical complexity and maintenance of single rotor seems to be the constraint causing the big shift towards MRs.

Me..... I am holding out for a newer power system for MRs using a Tokamak nuclear fusion reactor to drive an onboard electric generator. ;-)
http://en.wikipedia.org/wiki/Tokamak_Fusion_Test_Reactor
Click to expand...

Hehehehe :) .. Thanks for the hint

Khaled
 

Old Man

Old Man

Active Member
Lotta power to be had with methanol nitro combinations but you just have to use so darn much of the stuff in there to get it. I used to go through nitro blends about 5 times faster than I did with straight gas. Went a lot faster with the nitro though:) Anymore I think a long cord hooked up to a hydro electric plant is about the cheapest way to go.
 



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