Anyone used a Warp Drive prop?
 

Does anyone have any experience with Warp Drive props on RVs?

What I have in mind is 3 high HP blades in front of an O320. Warp Drive sells a spinner to match RV cowls, but I have never heard or read anything about anyone who has actually done this.

What I am trying to accomplish is getting my RV-8 in the air for minimal $. The ground adjustable pitch seems like a nice feature.

What I do not want is a death wish. Is there any information about vibration testing these props on various engines at various pitch settings? I am talking about the same kind of harmonics that caused Sensenich to limit their O320 aluminum prop to 2600 rpm.

Also, somebody told me something once about a flixible composite prop that acts sorta like a flex fan. It supposedly gives a partial effect of having a constant speed prop in a fixed pitch? Does anybody know anything about this? I have been unable to come up with anything on my internet searches.

Quasi-Constant speed prop
 

This is kinda funny. I had never heard of this quasi-constant speed prop before, but one of our new Aero's at work mentioned it to me this morning, about an hour before this post popped up. He said, to the best of his knowledge, it was developed out of a flight lab at Mississippi State under a NASA SBIR. I found the following info:
http://sbir.gsfc.nasa.gov/SBIR/succe...3-085text.html

There's also some information about one of the guys (Calvin Walker) who worked on it here:
http://shrike.erc.msstate.edu/raspet/pages/staff.html

Paul
RV-7 Finishing

There's a company in Australia that was developing an electric constant speed prop using these blades. I was to be the beta tester. After many problems with harmonic vibrations, they finally gave up. The company has many constant speed props for engines up to 100 hp (mostly reduction drive engines), but they could never get the props to work well with higher hp direct drive engines.
I know several people who tried Warp Drive props on RVs. Never got even "fair" performance.

I have flown behind a couple of Warp Drive props and just didn't think they performed all that well. Do yourself a favor and get a wood or metal prop designed for your airframe and engine combination, there are plenty of them out there. Your prop is not the place to go cheep. Don

It's old....
 

Paul... it's been around for ages as the Warnke "Almost Constant Speed Prop", using the flexibility of many laminations of wood and a curved blade shape.

Steve Barnard's RV-6A that was tested by the CAFE folks in 1993 had one installed....

http://cafefoundation.org/v2/pdf_apr...inal%20APR.pdf

I believe the Warnke props are still being made, but their web site seems flakey.... I also bet few of the newer RVs are using wood props any more... :)

gil in Tucson - original location of the Warnke props...

I have one of those. Works ok but the part I needed was the noise reduction, it is very silent.
As a business I can understand they went bust. One of these props was a close price match to a CSP prop...

Get in the Air
 

If you want to get flying for short $$, Ed Sterba will still make you a brand new wood prop for your RV for $650 or so. You can't beat that and he's been making them forever.

Bernie W. died some years back and, I believe, his daughter took over the business for a while. Somebody must know for sure if they are still in business or not.

Lastly, when evaluating any option, I was always told to ask FIRST!!!: "How many are flying with it?" If the answer is none, there's probably a good reason.

Good luck with your project.

John

Big Block-I just noticed you are in Manhattan, MT. Just 50 road miles north of you is Townsend. A Rans Builder there runs Warp Drive props on his 100hp Rans. He is also a RV-4 builder. If you want his contact info, let me know.

Gill, I wouldn't say that in front of all of us running Catto props.

Warp drive
 

Posted for a friend who saw your question.

I had a warp drive prop on my O320 until last month when I discovered cracks on the rear hub at the base of each prop. I had less than 100 hours on the prop when the cracks were discovered. I contacted the original builder and he said the hub and prop were, at one time, rated for that engine but when I contacted warp drive people they denied that claim. They said they would have never sold that combination and recommended that I purchase a four bladed hub. I have since located on the internet other failures with engines a lot smaller than the O320.