Silent prop for drones.

Airboat propeller discussion.
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Whitebear
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Silent prop for drones.

Post by Whitebear »

Any one with drone experience, can you tell me what RPM the props run at? Think its time for some silent drone props and injection molding is just the small scale ticket.

Who makes the most silent prop for airboats now days?

I can see a cottage industry opportunity if the majors don't think its worth their time and money. Many running professional drones complain they are too loud to work at the early morning and late afternoon hours when the air is still. That would be in urban surroundings or any sound restricted areas.

Scotty :old_glory:
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Jssflyer
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Re: Silent prop for drones.

Post by Jssflyer »

Hi Whitebear.
Just like bigger props and different set ups use different speeds. Generally speaking a 8-10” prop like on a drone will spin around 8000 rpm.
In the beginning years, like now. These drones are really just trying to get maximum lift and quickest responses. Hence the very loud props. There definitely would be a great market for quieter props. The problem is that you would have to change the programming to match the lower pitch, stiffer prop. If the machine tried to fly the props the same, it would only be a marginal difference. By using less volts, you can spin the motor much slower, turning a much larger prop without the need for gearing. This would drastically reduce noise while not weighing as much. Variable pitch props, instead of variable rpm would also drastically reduce noise, while increasing size to slow down and quite the props. You will lose precision and quick inputs in flight...don’t know if the operators would like that...could probably be solved with some engineering.
But surely one of the manufacturers could and would see the need for a “Whisper” drone.

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Whitebear
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Re: Silent prop for drones.

Post by Whitebear »

I agree at the smaller hobby scale of things. Many of the pros are running 30-36" props for movie production and even some large scale inspection jobs. like you said if it becomes or really is a problem with the sound, then the majors will likely jump in and fill the niche themselves leaving the Cottage guys not able to compete. Sure seems to me to be a niche but the mjajo5s may already be on it as were talking here. Fun to think and talk about it though..... I already got beat out thinking I could fill a niche in airboating with intercoms and radio interfaces. The big guys can afford to have them made in Taiwan, Korea, or Mexico and there was no way I could even come close t0o competing. The props may be the same story. Grinn
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
that they have not first taken from someone else.

Aeon
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Re: Silent prop for drones.

Post by Aeon »

Only the small drones use plastic props and trying to compete with china will only be pain and suffering. Plastic props are cheap.
So the kv rating on motors is voltage x rating so the dji phantom has 960kv motors so with a 15v battery its about 14k rpm

My big lifter hexacopter has 15"props and 380kv motors and 25 volts so about 9500rpm at max. At 200 feet you can't hear it as it hovers. The props are catbon fiber at this size

Go look at how cheap you can get parts on highmodel.com
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Sniper
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Re: Silent prop for drones.

Post by Sniper »

Hey whiteBear have you ever thought using a 3D printer to make the prototype props might be a economical way to get started
Sniper You can run but why die tired, If you heard my shot you were not the target
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Whitebear
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Re: Silent prop for drones.

Post by Whitebear »

I''ll have to check on the price of a 3D printer that can do that. I know there is one guy in the news recently selling or giving away plans, instructions or the program for an AR Lower Receiver and he came within a gnats butt going to jail for it. I still cant figure that since it is NOT illegal to make your own tuns. You just can't sell them etc. Hmmmmm

Got friend in the business out in Arkansas, think I will call her next week abut this 3D stuff.
"The Constitution is not so the government can restrain the people, it is so the people can restrain the government." Patrick Henry
The government cannot give anything --
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Slidin Gator
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Re: Silent prop for drones.

Post by Slidin Gator »

If you don’t want to invest in a printer now, check out Quickparts in Atlanta. They are pretty reasonable for small parts and offer a lot of manuf options. I use them a lot for models and prototypes.

Injection molding can cost $50k for molds. Parts cost pennies after that.
I still think I-10 is the Mason Dixon line.
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Prototype
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Re: Silent prop for drones.

Post by Prototype »

I'm up for the ngr's for the inspire and phantom.

The winglet don't fit nicely packaged so sound is probably not the main goal.

Are we sure your thought is not working backwards to prop companies using drone props for boats?
JX is about as close as it gets to making something idle in place or hover.

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