Help me identify this mystery prop

[Jim Hoffman]

Can anyone identify these props and perhaps discuss its design/application?

•   There are very nicely made and stiff carbon fiber props. 
•   The forward surface is a carbon matt material
•   They measure 10 diameter and a 4 pitch.  The max chord is 1.5 inches
•   They are VERY highly under-cambered

I would surmise the designer wanted to generate a high load (under-camber) but keep the rotary moment of inertia very low by concentrating mass as shown instead of adding more diameter.
 I’ve not seen anything quite like this.  They came from an estate of a guy who was fascinated by stunt, CL speed, and FF.  He was more of a collector than a flyer

[Brett Buck]

Can anyone identify these props and perhaps discuss its design/application?

•   There are very nicely made and stiff carbon fiber props. 
•   The forward surface is a carbon matt material
•   They measure 10 diameter and a 4 pitch.  The max chord is 1.5 inches
•   They are VERY highly under-cambered

I would surmise the designer wanted to generate a high load (under-camber) but keep the rotary moment of inertia very low by concentrating mass as shown instead of adding more diameter.
 I’ve not seen anything quite like this.  They came from an estate of a guy who was fascinated by stunt, CL speed, and FF.  He was more of a collector than a flyer

   Stuart Sherlock, AKA Joe Supercool

http://www.supercoolprops.com/index.php

http://www.supercoolprops.com/price_list2.php  (11-5 Petal Blade) I think this was made at the request of Aldrich, to enable flying 7-7.5 second laps, which they used to do "all the time".

      There are also amazingly good nuggets in the "articles" section, highly recommended reading.

     Brett

[Dan McEntee]

   I might not have thought of the name right away , but I remember the late Jim Thomerson having some of these and really liking them. The 'Supercool props" rings a bell and Brett is right on with the name. Jim used them a lot on several of his OTS models. His were the only ones I ever saw.
  Type at you later,
  Dan McEntee

[De Hill]

These 10-5 props worked well on Fox .35's. I have a carbon fiber version and a wooden version.

[Ken Culbertson]

These 10-5 props worked well on Fox .35's. I have a carbon fiber version and a wooden version.

I have seen something similar back in the early 60's but for whatever reason I stuck with the 10-6EW.  Probably because that is what the grownups were using.
The thought of a 7.0 lap time has me drooling.  I like them to fly slow and pull hard.  Hard to get both at those times.  I do remember the slow, verge of stall patterns with their ridiculous corners and free flight overhead 8s'.  Memories.....

Ken   

[Brett Buck]

The induced drag vortex on those must be amazing.

   I would also expect it to have an extreme version of the "drag bucket" that Igor first described on SSW. This would have had the effect that George claimed for it (really starts pulling in the corners), although his proposed mechanism was much different, and charitably, fanciful. It is just what you would wind up with by trial and error on an engine with an extremely "flat" break like the Fox.

     Brett

[Brett Buck]

I have seen something similar back in the early 60's but for whatever reason I stuck with the 10-6EW.  Probably because that is what the grownups were using.
The thought of a 7.0 lap time has me drooling.  I like them to fly slow and pull hard.  Hard to get both at those times.  I do remember the slow, verge of stall patterns with their ridiculous corners and free flight overhead 8s'.  Memories.....

     Build a Nobler and a Fox, and have at it. I suggest doing the 7-second lap test over tall grass, and wearing track shoes.

    Brett

[Ken Culbertson]

     Build a Nobler and a Fox, and have at it. I suggest doing the 7-second lap test over tall grass, and wearing track shoes.

    Brett

Hey, I can dream can't I?  If they gave trophies for the closest to the center of the circle you crash then a Nobler on a 7 second lap might win!  

Ken