9 replies to this topic

[jes1111]

http://www.theengine...icle?cmpid=TE01

This seems interesting, since the same should apply to our small size blades. Pity there's no picture/illustration.

[elmuchacho]

Indeed it apply and some swiss F5D pylon team have produced some.

Video of a training session the sound that prop is making is absolutely awesome

A forum thread that also discussed it.
http://www.rcgroups....=1293011&page=3

Unfortunately without some kick-ass algorithm to simulate airflow and correct fluid dynamic this is impossible to do

ps: this is also known as whale power http://www.whalepower.com/drupal/

Edited by elmuchacho, 01 February 2012 - 02:27 PM.

[Dado]

Germans are brilliant as always!

[Spydmobile]

This article is very good:
http://memagazine.as...Whales_Fans.cfm
Franco

[Spydmobile]

I wonder if one could modify our typical 1045 blades and do some thrust tests....
F

[Dado]

Spydmobile, on 01 February 2012 - 02:56 PM, said:

This article is very good:
http://memagazine.as...Whales_Fans.cfm
Franco

Thx for the article, very intriging.

[elmuchacho]

Not really but it will be possible Unfortunately highly costly because each modified/sanded prop that don't produce more trust end up in the bin. it will also be really difficult to produce 2 similar prop by hand

The technical doc I could gather also state that tubercule or whale bump will increase trust only if you increase pitch mainly because the whale bump allow easier airflow over the prop and this translate by being able to increase pitch quite a lot. But without changing the pitch your trust will actually drop on you 10x4.5

Even if you have the money and hand craft skills this could become or replace your hobby on a full time basis

ps: If I remember correctly I saw some of this sawtooth prop on a german site for sale but they where speed prop (exploiting dynamic trust)

edit: The F5D implementation from the video show that to acquire equivalent speed performance The prop size they use is way over 10inch when a conventional F5D use 4inch prop they also used a gearbox and not direct drive to accommodate.

Edited by elmuchacho, 01 February 2012 - 03:16 PM.

[Spydmobile]

Hmm perhaps we need someone to 3d print them???
F

[elmuchacho]

Spydmobile you are right a 3d print will work perfectly to make a mold. Once the mold created you can try to make a few prop. I will recommend to get the mold CNC milled into aluminium allowing the prop sandwich to be pressed mechanical. This will create a much stronger prop with an even density.

[Caustic]

Interestingly, they seem to be ignoring the other aquatic animal based discovery. The micro-dimpling of shark skin that accelerates objects in air and fluid. Time to combine both?