Well just as the tittle says, a new design is out and looks great, hope to see some of this props on the 9'' , 10" , 11" and 12" dia. size. 

For more info. here is the full article.

http://www.flyinggiants.com/forums/showthread.php?t=63180

 

As we all know when someone claims to have invented something that goes against the established norm we all are skeptical and we all raise a lot of questions. I was no different when I started following the thread created by Josh McBride (Ion01). Josh said that he had a patent pending revolutionary new idea for increased propeller efficiency, increased thrust, reduced load on the engine, etc. Pretty much all the things that we really would like but thought were impossible.

So when I received a p.m. from Josh asking me to check out this new product he has created I jumped on the chance. Without having any inclination of what he has done to this point, I met up with him at a local RC field in Guthrie, Oklahoma and, low and behold, there was something that I wasn't quite prepared to see. As you can see from the photo it looks like an exaggerated scimitar prop, until you do a double take and check the direction of rotation. As you can see the tip of propeller is forward of the hub. I must confess, I am not an engineer, but I do understand the principle of a forward swept wing. And that is exactly what this design is.

So now we get down to the testing! Josh had a standard Bolly 23 x 8 bolted onto the front of his DL – 50 engine that was mounted on his Double Vision. We ran the engine on the ground and it produced 6,800 RPM. I then flew the airplane through the entire flight envelope to get a baseline of flight characteristics. Josh then bolted on his propeller onto the Double Vision. This prop has the same diameter and pitch (23 X 8) as the previously used propeller. After warming the engine up again the tach read 7,500 RPM's, giving an increase of 700 RPM's over the previous prop. I know that rpm readings are not indicative of the actual performance of the propeller/engine combination but 700 rpm is a huge difference and I was ready to fly it and see. I proceeded to fly the plane through the entire flight envelope again. There is a distinct noise that this prop delivers, but it never ripped even when it unloaded. The engine responded quicker to throttle inputs and performance was improved in vertical maneuvers including pull out from a hover. I must add that it takes a lot of guts to design, develop and produce something this is completely different than what we are all used to. I applaud Josh for his vision and hope that he is successful in his endeavor. Thanks for being a Giant! 

One last note,I will be using one of these on my 50cc bird!

Current thread http://www.flyinggiants.com/forums/s...ad.php?t=56581
Website: http://revolutionaryprops.com/


Here are a couple of questions I had for Josh and thought I would share them with you guys:

Josh, What was your inspiration for this design?

I have always loved and been fascinated by the exotic look of the X-29 and the huge advantages of the forward swept wing. Then when the airline industry become so focused on the reduction of the wingtip vortex and the huge savings that resulted I began to wonder what could be done to a prop to provide the same improvements. In recent years RC Propeller designs have attempted to make the same improvements I was so interested in but I never saw a forward sweep. With the instruction of affordable carbon fiber construction, providing the strength necessary for the forward sweep, it occurred to me that material strengths must be the main reason this configuration had not be used in the past just like on aircraft. So, I figured this was my chance to finally bring the well known advantages of the forward sweep to the propeller.

Are there more sizes of props available?

Currently, we only have the 23 x 8 due to the start up costs but plan to bring many sizes to the RC industry and eventually move into full scale aircraft. In the short term, once we regain some of our expenses, our next prop will be for a 120cc and we will continue bring other props from there.

Do you have any data on the propellers performance other than RPM’s?

I was very careful during testing to ensure the only variable was the sweep of the propeller to eliminate any other “contributions” to the measurements/performance. I measured RPM’s, “wind speed” of the prop wash near the fuselage (important to 3D performance), and static thrust (those familiar with propeller design will realize that static thrust does not show the actually thrust generated in flight as a prop is designed to move through the air and not be static.) All measurements were taken at the same throttle positions in the same atmospheric conditions as well. All areas showed a clear increase in performance. I will have charts illustrating these increases on the website revolutionaryprops.com soon.

As this design is a departure from the norm, what would you say to someone who is skeptical?

The advantages of the forward swept wing have been known since the Germans first experimented with it in WWII. With the X-29 and the SU-47 the advantages have became well established. Considering it provides such large advantages to such performance aircraft it only follows that there would be advantages to a propeller which is really just a wing that rotates. Simply, it’s a simple, well known concept and I was just lucky enough to be the first to apply it in the most advantageous form on a propeller.

 

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Comment by MarcS on April 18, 2011 at 3:01am

Wow, thats an unusual look :-) First looks like a running motor filmed by a rolling shutter camera...

Would like to see wind tunnel measurements for comparison. It´s really hard to tell differences from real flights...

The drawback I see from the construction is that you will get a good amount of torsion in the propeller so you will have to built it much stiffer than a comparable straight/normal prop. So it will most likely be heavyer with the same RPM rating...

Comment by Mathew krawczun on April 18, 2011 at 8:37am

I wounder about the over all life of this prop, from what I know about forward swept wings I would expect this to have an over all shorter life span but it should be worth it becaue of the boost in performance. 

Comment by Andrew Rabbitt on April 18, 2011 at 8:45am
Anything to do with this patent application...? http://www.google.com/patents/about?id=kYiVAAAAEBAJ
Comment by Andrew Rabbitt on April 18, 2011 at 9:17am

Hmmm...   Is it really wierd that my USPTO searches on patent applications show no mention of the founders Joshua and Benjamin McBride...?

Comment by Ramon L on April 18, 2011 at 11:02am

Does propeller blade have the same meaning as propeller? IMO noup. Any prototype pictures from that? noup, its just drawings, and very diffrent stuff haha , those blades dont look nothing like the shown on the photos.  That blade design is only an approach of the forward swept wing concept, I mean both are but  the one shown on the patent is very basic compared to the one on the pictures. 

i guess the founders dont appears beacuse it is on patent pending...

Comment by Ramon L on April 18, 2011 at 11:10am

Mathew I found some info about that on their website :) they claim that

"By using the latest in carbon fiber forming technology we have also made the propeller extremely light by making it hollow without sacrificing the much needed strength to handle the increased forces of the design".

 

Comment by Andrew Rabbitt on April 18, 2011 at 12:40pm
Hi Ramon, The only thing that counts in a patent is what's described in the claims. The bulk of the text and any pretty pictures are meaningless from a patent enforcement point of view. I'm guessing it's pretty hard to make a propellor without putting propellor blades on it...

And anyway, the fact that that patent applcation exists could be easily construed as prior art, making it hard to justify the issue of a patent for a very similar idea. They would have to get the patent examiner to agree there is something novel to making the leading edge of the thing curved instead of straight.

My main concern is that the patent attorney is taking money from them without any chance of legal success and the value of the patent is only as deep as their pockets are to defend it.

IMHO, this is why most patents are a waste of money at best and an impediment to technological progress at worst. It just takes a bullying multi-national to squash any sense of innovation by the little guy...
Comment by MarcS on April 18, 2011 at 1:39pm

Patent issues...  Thats the problem with this business. Engineers are actually more concerned about patent law then designing something... But let´s not try to change the world.

Regarding the "latest in carbon..." We built hollow carbon props from molds years ago... And as I said before. Just think about mechanics: There is a force on the surface of the prop. Since it is bend, this produces a torsion (force multiplied by distance). Thats something you don´t have on a straight one so it will definetely be heavier when having the same thrust parameters.

And here something about the "revolutionary"... http://www.reflektion.info/3001_210807_1_u11_prop_1001.jpg

The guys flying underwater know this shape since year (but out of other reasons, like cavitation...)

Comment by Juan Soler on April 18, 2011 at 2:48pm
While I like the design (and am yet to read any independent study results examining the performance of this prop against the more widely available designs) I cannot help but feel apprehensive about having a a dangerous looking leading edge like the square point on the end of each blade.  Why not just round off the ends?  That point looks ready to slash someone's arm off :)
Comment by Ramon L on April 18, 2011 at 3:50pm
Juan any prop can do that, the design dont have to do anything with it. Just keep your hands away from it jeje

Well I hope he gets his design going and get the patent because the design looks great, what he claims sounds promising and far away from a drawing he have it working. You guys know a lot about patents, its a shame that a patent can be used to undo...

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