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Choose gearbox to direct-mount a quad-coptor rotor.

Choose gearbox to direct-mount a quad-coptor rotor.

Choose gearbox to direct-mount a quad-coptor rotor.

Aviation-rated reduction gearboxes 10:1 55 kw prop mounting.

I need to find an appropriate company that does this. I found a good one for motors and controllers, but they don't do gearmotors.
I suspect industrial gearbox makers don't want their products used for this.
There is about 6 kN pull, 390 Nm torque, 1000 rpm out, 5m rotor, solid, composite, so some rotational imbalance and bending loads.
So far, nothing relevant is coming up in google searches.
Can you give advice on better query structures?

RE: Choose gearbox to direct-mount a quad-coptor rotor.

It looks like this type of gearbox is non-standard.

I have found an electric motor that runs at 4000 rpm with the correct power output,
so I need to have a custom box made up at 4:1, and inline epicyclic.

I could fit the output shaft of the standard 2.5 (say) offset box to the gears from an an industrial in-line
reduction unit, but the end bearings would need to be uprated. possibly some kind of taper rollers.

The airboat box bearing set could be considered, if there is enough clearance for the rear bearing set.
This can be much lighter, as no pull-out loads and little continuous side-loading.

Also, shaft retention needs to be considered-fit bearings from the front, mount the gearbox to a custom
front cover, external braces/housing to pick up the motor mount/coupler housing at the other end.
Do you have any ideas on a better way to do this?

Also, a standard airboat box is about usd 3500. I don't want to spend an order of magnitude more getting this done.
Thus, fabrication and machine rather than mill from solid?

I am still awaiting replies from gearbox and motor people.

RE: Choose gearbox to direct-mount a quad-coptor rotor.

It's a specialty item. You'll probably have to have a custom unit designed and built for you.

Never dealt with them, but I've seen the name before, and it ought to be within their capability... http://www.flender-graff.com/download/

Some questions I'd like to ask, whose answers will affect your goal by an order of magnitude (not exaggerating).

1) carrying human beings? Yes or No
2) one-off or production?
3) legal in civilian airspace over North America/Europe?
4) passengers will pay money to embark?

If your answers are "no" "one-off" "russia" and "no" then I won't be able to help you but you will have fun if you don't get shot down.
If you answered the other way, the complete end product will cost about 10,000 times more than the first option would. Again, NOT exaggerating. However, this is a domain we might be able to help you with. This and other questions you've asked elsewhere hint that you are in the concept phase but taking it seriously enough to look for suppliers and partners for the major subcomponents. I can't glean any other parameters about the experience of you or your team so hopefully you can fill us in.

Also, if you are expecting to follow the civil certification route, then I can't recommend strongly enough to get a licensed pilot, mechanic, and designer with specific experience on helicopters into your team, if at all possible. If somehow you convince yourself that this isn't a helicopter, or doesn't need to meet the design safety standards of a helicopter, you are wasting your investors' money.


RE: Choose gearbox to direct-mount a quad-coptor rotor.

Possibly carry passengers (non-paying?) + pilot. -eventual goal.
Extensive ground testing, tethered flight, and remote-control flight tests, are planned.

Possible one-off certification as experimental. I will check regulations, inspection, and testing requirements.

Use of uncertified electronic motor controls may be a sticking point. the motor supplier does also supply the controllers.
There may be a requirement to provide and prove full redundancy in the electronics, and analyse soft failure modes.
There will be some flight stability automation required as well. the controls may need to be multiplexed together in some way to fit
standard helicopter controls. Platform level, and directional stability is an issue.
Station-keeping override would be nice,
And landing assistance, rate of decent control, ground proximity "nannies" etc. Less chance of piling into the scenery.

Use only in New Zealand for now.

Possible commercial value: Supply kits to on-off builders, bundle up the electric motor/gearbox/rotor hardware and sell it on?

other possible uses: publicity, proof if concept, technology demonstrator to use to help support other activities and finance raising.
(hopefully not fraudulent)

The initial 100 grand or so in component costs would be a problem for me.

There is an outfit in Russia called Airprop who seem to know how to make gearboxes-I don't know about making rotorcraft-grade
designs though. I can test the hell out of the box/motor/rotor combo before fitting it in an airframe, though, which is worthwhile if I can buy it cheap, with some design vetting. (correct output shaft, bulletproof well-supported low carbon steel planet carrier, etc.
They make a lot of airboat gearboxes. They don't seem to give their full company designation, which leads me to believe they are sort of informal- is this common in Russia? Their website looks pretty good.
Enforcing performance of payment/production of goods/quality may be a bit tricky???

There is no team at present. I will talk to a few people and see if they want to get involved. Making a good business case may require a lot of creativity and lateral thinking.

RE: Choose gearbox to direct-mount a quad-coptor rotor.

Design News often has advertisements for gear-box manufacturers... However...

SW has provided You Fair Warning.
Breathe the words aircraft, aviation, aerospace, unmanned or manned-flight, etc... and most industrial vendors will instantly (a) 'hang-up' or (b) turn You over 'to the aerospace side of the business'.

Years ago I realized that MOST turboprop engine installs were actually the equivalent of two engines mated together... turbine powerplant/inlet/exhaust/systems + the interconnecting shafts/gearbox/prop/systems... each 'engine' with its own unique design/concern/maintenance/etc. This is fairly equivalent RE what You seem to 'need'.

There are a few manufactures concentrating on aircraft electric propulsion... integrated [weight/efficiency sensitive] motors, batteries, controls, systems [etc] with integral gearing/shafting-mounting/control output to a prop.

Electric propulsion is receiving some attention at https://www.homebuiltairplanes.com/forums/

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

RE: Choose gearbox to direct-mount a quad-coptor rotor.


The initial 100 grand or so in component costs would be a problem for me

That might be what it costs for them to pick up the phone/answer e-mails. Just by gut feel... more cash is required to get the product delivered to the loading dock of your shop.
Just one set of gearboxes?
Your title is "quad" copter... so is 4 enough?
Have you read FAR 27.903?
I assume you want the gearboxes to match, perhaps be interchangeable. Bonus even that you might be able to repair them, run them for a few thousand hours before they are scrap, and expect to find a replacement when that day comes...

What about the other 100 sub-component systems you'll need?


RE: Choose gearbox to direct-mount a quad-coptor rotor.

For now, there is no pressing business case to continue, and this approach is a bit expensive to obtain a hobby aircraft.
The version paralleling Robinson R44 performance specs seems to be feasible using petrol-electric drive. A good weight, rotor area, power, range match.

I have no desire to travel large distances in my own aircraft. How about a big swing to full visual telepresence on a fairly
high-end quadcopter drone? "Beyond visual contact" multichannel communications? - maybe just line-of-sight, 500 or so yards for now....
I haven't had a radio-controlled quadcopter yet. Fitted with enough cameras and telecoms, it could be fun.

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