Is it a bird? Is it a Plane? Is it a Helicopter? Nope - I'm building one of those new drone thingy's!

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SpamIsHam

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Some more reading.

Hey mate - nothing really new or unforeseen in the articles you have linked, but an interesting read none the less!

I think it’s interesting that the US is so far going down the route of no licence required for these - I can’t help but wonder if they might have underestimated the accessibility these will offer a vastly larger number of people to being in control of an aircraft - when the numbers and bodies start piling up due to negligent flight operations or failures over populated areas they might rethink this.

I agree that at minimum an RPL should be held by anyone operating one of these, if for nothing else but a genuine grasp of the hazards around them and for the best of everyone else if not themselves.

I have a fantastic idea for the use of this though that was discussed in this meeting yesterday and a light bulb has gone on in my head. It won’t require operations in controlled airspace either.

Honestly, my biggest concern now is how to safely solve the problem of the “dead mans airspace” that 20ft-200ft operating altitude that won’t allow time for a ballistic chute and is too high to survive an impact from.
 

Tiger Tim

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Honestly, my biggest concern now is how to safely solve the problem of the “dead mans airspace” that 20ft-200ft operating altitude that won’t allow time for a ballistic chute and is too high to survive an impact from.
It could be as simple as minimizing transit time through that region. IIRC helicopters have a similar speed-altitude region where they can’t be assured of a transition to autorotation.
 

REVAN

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The Motors are T-Motor units either U15XXLKV29, or U15KV80 which are off the shelf availability for about $900
FYI: I think the Jetson-1 uses MAD M40C30 motors:



I could be wrong, but at one point I had convinced myself that this is what they were using.
 

nerobro

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I haven't seen refrence to this previous work in this thread. But... You should probally take a look at this guys work.

This is his all electric version. He's made them with gas engines too.

"been done, proven to work."
 

REVAN

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Honestly, my biggest concern now is how to safely solve the problem of the “dead mans airspace” that 20ft-200ft operating altitude that won’t allow time for a ballistic chute and is too high to survive an impact from.
For a quad copter type of machine, you simply rely on the system redundancy to save you from a single point failure. That's why there are two motors/props per boom. Jetson-1 is an octo-copter in a quad-copter format. If the redundancy fails, it is generally going to be catastrophic. As you can see from the videos of Jetson-1, it never really flies high enough to use a parachute system. If flying low enough and slow enough, the crash cage might save your life, but you will get banged you up pretty badly.

What these systems need is a rocket system that can slow the fall to survivable speeds and an airbag system for a Mars Rover style landing.
 

SpamIsHam

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OK, well past due for an update but I met with the engineers two weeks ago, I have had to convert all my drawings to CAD so that the aluminium tubing can be CNC rolled - that’s been done now. In the meantime I have built a full size mock up frame out of PVC pipe, which I have heated with a heat gun and bent as required - it’s not super accurate but it’s good enough to use for doing a rough fit out of the bits and pieces and learn where there will be snags in putting the metal frame together. Will try to upload some pics!
 

SpamIsHam

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For a quad copter type of machine, you simply rely on the system redundancy to save you from a single point failure. That's why there are two motors/props per boom. Jetson-1 is an octo-copter in a quad-copter format. If the redundancy fails, it is generally going to be catastrophic. As you can see from the videos of Jetson-1, it never really flies high enough to use a parachute system. If flying low enough and slow enough, the crash cage might save your life, but you will get banged you up pretty badly.

What these systems need is a rocket system that can slow the fall to survivable speeds and an airbag system for a Mars Rover style landing.
Sounds heavy and expensive - also a problem if you are upside down, which is entirely possible if you loose a couple of engines on a quad setup…

They really are problematic in this sense. The first part of what you said though might just be entirely right - it’s a full reliance on redundancy. I just like the idea of having a “**** you airplane, I guess I’ll save us then, if you won’t” option
 

SpamIsHam

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FYI: I think the Jetson-1 uses MAD M40C30 motors:



I could be wrong, but at one point I had convinced myself that this is what they were using.
Sorry just saw your post!
Thankyou for the info - very helpful!
You might be right about the motors, I’ll look into them now - huge help! Thankyou! 🙏
 

SpamIsHam

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I haven't seen refrence to this previous work in this thread. But... You should probally take a look at this guys work.

This is his all electric version. He's made them with gas engines too.

"been done, proven to work."


I don’t like the idea of having so many engines - honestly, I think the problem is (apart from looking fugly), I have never seen an electric motor fail on its own merit. I think I have covered this in a previous post, but they are such simple devices, there really isn’t a whole lot that can to go wrong in them. I have bigger concerns with the wiring to the motors and the distributor boards etc. The more motors the more wiring and more complex the distribution boards etc - the more that can go wrong. I feel like it’s more likely you will have an all out failure than a single motor failure.
 

nerobro

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I don’t like the idea of having so many engines - honestly, I think the problem is (apart from looking fugly), I have never seen an electric motor fail on its own merit. I think I have covered this in a previous post, but they are such simple devices, there really isn’t a whole lot that can to go wrong in them. I have bigger concerns with the wiring to the motors and the distributor boards etc. The more motors the more wiring and more complex the distribution boards etc - the more that can go wrong. I feel like it’s more likely you will have an all out failure than a single motor failure.
There's a lot of times where a difference of opinion is just that, in this case, it's not.

So, lets talk about a single electric motor. We'll even make sure it's a permanent magnet motor, so we don't have to worry about brushes. Things that can cause it to fail: Vibration causing a short in a winding. Cracks in the stator causing loss of flux, and a reduction in power output. Magnets breaking off the motor bell. Overheating causing windings to burn and have a short. Motor controller failure causing a winding to short. Motor failure causing wiring to fault (read: become fusible link, catch fire, or start moving..)

Things that can cause a motor controller to fail. And the list here is a lot more interesting. Bad driver IC's. Bad communication from the flight controller(s). Bad caps on the board causing the microcontroller to flake out. Bad flash on the microcontroller causing it to lock up. Back emf being to high, and frying some of the protection circuitry. Inductance on the lines causing the input voltage to be exceeded. A stalled rotor blade causing high startup currents and popping the motor controller. A broken wire from the flight controller.

There's a reason that there's redundant flight computers on unstable aircraft. In the case of the guy you're watching he's got IIRC, four different redundant systems. So if any ONE of them goes out, he doesn't lose the aircraft. That's a thing shared by everything that's dependent on flight controllers. They make it a point that there's as few single points of failure as possible.

That's not a thing they're doing wrong.

"ugly" is a thing. That's fixable.
 

Appowner

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There is a guy who lurks in the dark corners of hangars. His name is Murphy.


BJC
Ha! Ha! Murphy and I are old friends.

Then again there's always the KISS principle. Do I have to spell it out?

And as Burt Rutan would say, “the technology you leave out cannot fail you.”
 
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