Anybody heard of tip fins or tip loading a propeller

[kaneboats]

So, I came across this propeller with tip fins on ebay. Seemed kinda strange. The ad said to look up "increasing propeller efficiency with tip fins". Made me wonder if it actually works and, if so, why ACME wouldn't already be doing this. Anybody seen this? Is it just a gimmick? Or is the difference so slight that it is just not worth the cost to produce? If someone posted this on April 1 I would be laughing.

https://www.ebay.com/itm/Acme-537-13-5-X-16-LH-Brass-HP-Propeller-1-1-8-hub-w-Tip-Fins-Acme-Puller-Kit/332626017376?hash=item4d720e3c60:g:X0QAAOSwALhaXrX 1

https://www.researchgate.net/publication/272021083_Improving_Propeller_Efficiency_Through_T ip_Loading

https://www.nap.edu/read/5870/chapter/64

[jmvotto]

Didn't vornado do this with fans ..

[Stazi]

Didn't vornado do this with fans ..

Similar in theory as the the winglets on the ends of airliner wings. It helps prevent the pressure drop at the tips due to the vortices that occur there. Would be interesting to see how it performs on a boat, and also if there is an extra noise etc.


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[Shoebox]

Looks like the q-tip airplane propeller. Seems like a good way to waste $345.

http://m.aviationweek.com/bca/remember-q-tip-prop

https://uploads.tapatalk-cdn.com/20180510/6fbd20c10ef7018f54068ffa0c9f5d14.jpg

[MLA]

might just be the pic, but 3 tips look folded and the 4th looks rolled. I dont think the seller realizes they have just a bent prop

[Shoebox]

might just be the pic, but 3 tips look folded and the 4th looks rolled. I dont think the seller realizes they have just a bent propSure he does. He also realizes there's a fool born every minute. [emoji23]

[kaneboats]

Gee, I bent 2 fins on my prop . . . think I'll just bend the other 2 to kinda match . . .

[Shoebox]

They don't look to be all bent exactly the same. The vibration would be ridiculous.

[5:00]

"Sold as AS IS condition with no return"

[zabooda]

Sometimes known as cupped blades.

https://images.search.yahoo.com/search/images?p=cupped+props+for+boats&fr=yfp-t-s&imgurl=http%3A%2F%2Fbblades.com%2Fwp-content%2Fuploads%2F2011%2F07%2Fcupping.gif#id=1&iurl=http%3A%2F%2Fbblades.com%2Fwp-content%2Fuploads%2F2011%2F07%2Fcupping.gif&action=click

[Stazi]

Sometimes known as cupped blades.

https://images.search.yahoo.com/search/images?p=cupped+props+for+boats&fr=yfp-t-s&imgurl=http%3A%2F%2Fbblades.com%2Fwp-content%2Fuploads%2F2011%2F07%2Fcupping.gif#id=1&iurl=http%3A%2F%2Fbblades.com%2Fwp-content%2Fuploads%2F2011%2F07%2Fcupping.gif&action=click

Cupping is typically waaaaaay more subtle.


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[zabooda]

You think? LOL.

[Broke Pilot]

Looks like the q-tip airplane propeller. Seems like a good way to waste $345.

http://m.aviationweek.com/bca/remember-q-tip-prop

https://uploads.tapatalk-cdn.com/20180510/6fbd20c10ef7018f54068ffa0c9f5d14.jpg

Agreed... lol