Gas powered multi, conceptual question

DucktileMedia

DucktileMedia

Drone Enthusiast
If you took a bunch of small gas engines, say cox .049's or equivalent and you mechanically linked them up to servos that were controlled by the esc ports of the FC, would you get any desirable results? I guess it would depend on how the esc ports controlled the servo but assuming it moved one direction or the other until it achieved a level position, it should theoretically work. Might be fun just to say you did it. or maybe just a completely stupid idea.
 

Macsgrafs

Macsgrafs

Active Member
26cc petrol engine in the hub, 8 heli tail rotors on the arms & use pitch to control each set of props...thats my idea of a fun setup ;)
 

kloner

kloner

Aerial DP
small nitro motors are so dependant on tune to run the same rpm, i'd imagine a group of em would e a nightmare. btw, motors like that are glow or model fuel.

gassers like gasoline come down to .50 size, way easier to tune but man, electric is so easy compared to. heavy too

Macs idea is feasable. I can't imagine making it film anything without gobs of isolation of some sort or another
 

D

DennyR

Active Member
A better solution would be 4 high performance racing RC car engines that run at about 40,000 rpm and give a lot of power with very good throttle response. You gear them at about 8-1 and then use a variable pitch rotor hub. idle-up throttle and normal fc control on the pitch. Any difference in output rpm would be compensated by the pitch control.
 
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DucktileMedia

DucktileMedia

Drone Enthusiast
I wouldnt do this to replace our electrics nor film with. More for the challenge of doing something different. But the main question is what would happen if you put servos in the esc slots? Does the feedback loop still work when it becomes mechanical? I think all the FC is looking for is to obtain level. It just outputs an educated value and keeps correcting until it has achieved the desired position. So in theory it should work, right?
 

Macsgrafs

Macsgrafs

Active Member
IrisAerial said:
I wouldnt do this to replace our electrics nor film with. More for the challenge of doing something different. But the main question is what would happen if you put servos in the esc slots? Does the feedback loop still work when it becomes mechanical? I think all the FC is looking for is to obtain level. It just outputs an educated value and keeps correcting until it has achieved the desired position. So in theory it should work, right?
Click to expand...

I agree it should work just fine, slightly slower response than ESC's, but it will still work nicely.

Ross
 


kloner

kloner

Aerial DP
would the brand/type FC make the difference on the answer? I've only played with naza, but aren't open source fc's pretty much a blank canvas that can do what you program them to?

i still thing something that small is hard to tune, especialy nitro and 8 of em. they have one needle carbs, etc. at least motors like the newer heli os's have 3 needle carbs, etc. the mid range thing's gonna be hard without it, they stumble alot throttling up without control of the fuel
 

N

nitroheadz28

Member
A smart idea would be to use airplane 4-strokes, they are way easier to tune than 2-stroke nitros and are fairly maintenance free apart from making valve lash adjustments every once in a while. They are also more fuel efficient than their 2-stroke counterparts, but run hotter and louder. They can however run at 100% throttle sustained without damage unlike 2-strokes.

They only spin to around 10-12k rpm depending on size, but you can always do some kind of gear induction setup.

Not too sure how it'd be possible to manage 4-6-8 of these at once and retain stable flight though.
 


DucktileMedia

DucktileMedia

Drone Enthusiast
I've seen better footage of Bigfoot! Cant tell what the hell is going on there. 1 motor in the middle or 5 motors? interesting though.
 

mitmit

mitmit

Member
gas engine in the middle for main traction and four small electrics for steering. not ideal construction as you need to keep middle part of frame opened for airflow, but could be useful for some tasks..
 
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RCNut

RCNut

Member
My experience with nitro motors is that unless they're perfectly tuned, they're a little unreliable at low revs. In fixed wing models they often cut out on approach leaving you with a dead stick landing. As long as you keep the idle revs well up you'd probably be OK though. Another thing is safety - starting all those engines while the others around you are running - unless you used nitro helicopter clutches to disengage the props at reduced throttle at the expense of extra weight.
 

hexa

hexa

Member
The best way would be to use a gasser engine as a generator to power the esc, with some added electronics for a lipo backup, with the right setup you could get 48 hours flight time. Fly to mars and back. Stop off at moon for a pint with twinkly tink and his pal humpy Dumpty.


Sent from my iPhone 4g using Tapatalk
 

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nitroheadz28

Member
*Whispers 4-stroke glow*



Significantly smaller and lighter than a gasser, no tuning hassles after its initially set up. How feasible would it be to use one as a generator?
 


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