hevansrv7a

hevansrv7a

Well Known Member
It can finally be made public.

I bought the first prop designed by John McGinnis (Synergy aircraft). It is being made by a new New Zealand company that can be found at:
www.kiwipropellers.com
It is designed for my 7A.
If you are here at OSH, the NZ compound is directly west of the Honda Jet tent a short ways north of show central. there are 3 prototypes there.
On the map as #406.

I am bringing the guys from the OSH NZ exhibit to the social at the beer tent tonight. Doug: come find us and they will probably buy an ad from you. Look for the white ball caps with green logo.

When I have flown the prop I will do my usual, honest, objective write-up
 
Update

The prop is on its way back to Kiwi-land (New Zealand) for a couple of reasons:

1. It will probably be changed so that it can be installed on my RV without a new extension. It's an issue of part of the blades being aft of the base of the hub in the current version.

2. John, the Mitchells and I all agreed on a good ground-testing plan which will precede putting it on my airplane.

The prop was a big hit at the show and many people expressed interest in having one designed for their airplanes - some of which are not RV's. But that is O.T.

Here are some things that I learned about it:
  • constant Reynolds number
  • 25 custom NLF airfoils blended, all by Synergy designer John McGinnis
  • some L/D ratios on some of the airfoils that are so high I won't say them out loud, here.
  • lift distribution more parabolic than elliptical
  • makes good use of the "q" near the hub
  • twist is less than "normal" because the necessary advance ratio is accomplished with airfoil design.
  • The airfoils adapt in thickness, camber, and design Mach number as they move outward. Keeping the Reynolds number constant prevents unnoticed lift/drag changes as those factors are varied in pursuit of the desired lift distribution.
  • all composite construction - no wood
  • I have not seen it yet but there will be a custom spinner with it
And, yes, the Kiwi's have begun the process of becoming advertisers on this forum. I put them in touch with Doug even though we missed him at the beer tent (where I was told he was not present).

One more thing: a few people tried to compare it to a Paul Lipps prop. I mean no disrespect to the late Mr. Lipps, but, no, that's not even close.
 
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Just noticed the Kiwipropellors website has been suspended.
Does anybody have any more positive news about them?
 
Kiwi Props

I have not given an update because I have not had anything concrete to say. However, the prop that John McGinnis designed has been redesigned and John tells me that there will be a production version but he did not say when.

The Kiwi folks may come back into it later, but I expect that the first production versions of John's new prop design will be produced in north America.

I still expect to put that prop on my 7A and see what it does. In the meantime I am refining some of my test techniques because I found some deficiencies in them. I will put out an article on that when I have completed the revision.

If things work as I expect, the revised testing and analysis stuff for my airplane will come first and then there will be a write-up on the new prop with the new techniques and analysis.

Sorry for the lack of really specific information. More to come.
 
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