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General control line discussion => Open Forum => Topic started by: Dick Byron on February 09, 2023, 08:07:06 PM

Title: Toroidal props
Post by: Dick Byron on February 09, 2023, 08:07:06 PM: I am sure this could be adapted to our use. Toroidal props.
Title: Re: Toroidal props
Post by: Lyle Spiegel on February 09, 2023, 08:23:11 PM: I look forward to reading abouty first flight using this type prop
Title: Re: Toroidal props
Post by: bill bischoff on February 09, 2023, 08:29:16 PM: was there supposed to be an attachment? ???
Title: Re: Toroidal props
Post by: Dick Byron on February 09, 2023, 09:21:41 PM: No just do a GOOGLE search.
Title: Re: Toroidal props
Post by: Paul Wescott on February 09, 2023, 10:08:10 PM: I agree they could be used in Control Line but why? Do we really need quieter props? I don’t think propellers are causing our noise problem. Am I wrong?

PW
Title: Re: Toroidal props
Post by: Steve Berry on February 10, 2023, 07:22:39 AM: From what I've read and heard, they are not just more quiet, they are more efficient. On an electric, I've heard up to 20% more efficient, which could translate into saving an ounce or two on the battery by not needing as big of one.

Big down side, though, is it looks like they are mostly 3D-printed, which may or may not hold up to our abuses, I mean, uses...at least for a prop. However....I supposed you could 3D print one, test it to see how well it works, and then use it to make a mold for a carbon fiber version.

Now, to find a spinner for such a critter.....

Steve
Title: Re: Toroidal props
Post by: Gerald Arana on February 10, 2023, 09:41:45 AM: Quote from: bill bischoff on February 09, 2023, 08:29:16 PM
was there supposed to be an attachment? ???

They look like a "Boat" propeller.

Jerry
Title: Re: Toroidal props
Post by: Ken Culbertson on February 10, 2023, 10:12:17 AM: Very interesting. I hope someone tries one of these. One thing I have been curious about. We are not supposed to use props made for drones. I don' t intend to but Why? Do they run at lower RPM? What is there besides RPM that determines if a prop is or is not appropriate for CLS?

Ken
Title: Re: Toroidal props
Post by: Brett Buck on February 10, 2023, 12:13:42 PM: Quote from: Ken Culbertson on February 10, 2023, 10:12:17 AM
Very interesting. I hope someone tries one of these. One thing I have been curious about. We are not supposed to use props made for drones. I don' t intend to but Why? Do they run at lower RPM? What is there besides RPM that determines if a prop is or is not appropriate for CLS?

Ken

On an IC motor, there are extremely large variations (100xish the average running torque) in the torque through a rev and a firing and everyone is concerned with these torque variations flexing and fatiguing the prop near the hub.

For electric, the danger is a prop strike removing a blade, because they are extremely brittle and there have already been several examples of light prop strikes that caused the blade to fling off. There's not a lot of danger to people but it will definitely destroy the airplane in very short order from vibration. The various FRP electric props are also not a good idea for IC for the fatique reason, but they are much tougher and a prop strike will not usually cause them to throw the entire blade.

Brett
Title: Re: Toroidal props
Post by: M Spencer on February 10, 2023, 05:32:37 PM: Theyd look good on one of these . S?P

(https://www.secretprojects.co.uk/data/attachments/223/223216-5639eb589b3e183a46f811dae4c1adb7.jpg)

n~

(https://media.printables.com/media/prints/392352/images/3278226_d7bfd284-6aef-41d8-8cf9-3c2e0bfee18e/thumbs/cover/1280x960/png/tri-toroidal-50x3.webp)

. Wonder about the MASS , gyro effect . Seems to be variable blade types .
(https://img1.yeggi.com/page_images_cache/5740041_5-toroidal-prop-for-efficiency-v2-by-willowehrich)

(https://media.printables.com/media/prints/392886/images/3281960_55472c39-9961-497f-acde-5d9954465087/thumbs/cover/1280x960/png/d1cff6f6-5794-485f-99c3-fd5670b7e38f.webp)

Then we could . . .

(https://d2t1xqejof9utc.cloudfront.net/screenshots/pics/338716af95f321fb8a6a45027a71f6af/large.JPG)

The ones with the flat ring around the outside - revolving - make it harder to chew your fingers up .

(https://www.fanquip.com.au/wp-content/uploads/2022/12/Fanquip_product__Impellers.jpg)
Title: Re: Toroidal props
Post by: M Spencer on February 10, 2023, 05:51:11 PM: (https://encrypted-tbn2.gstatic.com/faviconV2?url=https://aviation.stackexchange.com&client=VFE&size=64&type=FAVICON&fallback_opts=TYPE,SIZE,URL&nfrp=2)

Some might be more practical . LL~

(https://i.pinimg.com/originals/c1/91/54/c191547d9b1696f31dc4086372ff1b77.jpg)

(https://live.staticflickr.com/4453/37109540530_0e36768043_b.jpg)

Right, PROPS was it .

(https://www.orionairsales.co.uk/ekmps/shops/orionair/images/lg-air-conditioning-spare-part-0a00026b-fan-assembly-propeller-for-lgp08ah-ufo-8088-p.jpg)

(https://qph.cf2.quoracdn.net/main-qimg-a122288238f4f99a585cbbb7cc39fd57-pjlq)
Title: Re: Toroidal props
Post by: wwwarbird on February 10, 2023, 09:09:51 PM: I'll be sticking with the same old mousetraps. D>K
Title: Re: Toroidal props
Post by: GallopingGhostler on February 16, 2023, 11:19:40 AM: Enjoyed the posting of the new toroidals, wasn't aware they existed, seems promising. However until the newer technology becomes more available and affordable, (which seems still a ways off at our level), I'm sticking with the older, less effective but proven props. I gather that perhaps a better application may be in model boating, where it seems it would really shine. In that venue, the smaller sizes would be easier to manufacture.