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-   -   Vari-Prop...anyone use them? (https://vansairforce.net/community/showthread.php?t=90130)

whiskeypapa 08-23-2012 11:23 AM

YouTube
 
Search "Variprop" on YouTube and you'll find a nice little video by one of the canard folks.

YellerDaisy 08-23-2012 11:28 AM

Quote:

Originally Posted by TXFlyGuy (Post 692202)
A friend of mine bought a 4 blade propeller from Vari-Prop. Until today, I had never heard of them. Does anyone know about this propeller company? Are their props on anyone's airplane? Safety record, or lack thereof?
Inquiring minds want to know! I did a search but the info was almost 6 years old.

Sorry, I can't answer your question. However; Pat Panzera did a write-up on this hub in Contact! issue #89 back in 2007. I've never talked to any that actually flew with it.

ccrawford 08-23-2012 12:18 PM

Quote:

Originally Posted by Snowflake (Post 692316)
Corey, how is the hydraulic pressure conveyed to the hub? Some kind of sliding collar?

Here's a picture:


You can see the center piston (for lack of a better word), which manages the pitch of the blades. There is a pin at the end of each blade that slots into the piston. The hydraulic pressure comes in through the sliding collar at the base of the hub, you can see the hole from the threaded fitting. (You have to secure the fitting so it doesn't rotate, which may or may not be easy depending what you can use as a mounting point for a custom bracket).

Here's a picture of one of my blades:

rv6ejguy 08-23-2012 12:52 PM

I believe Mark Sletten and Kelly Landrum are both flying these props on Subaru powered aircraft.

timothywhigginbotham 08-23-2012 02:10 PM

[quote=ccrawford]I have one of their props (3 blade), but ain't flying yet. The props themselves are made by Props Inc (I think). They do have a solid epoxy edge.


Yes, that sure looks like a Props Inc blade. Mine also had the solid epoxy edge. The blade root looks similar to the one I had also.

Please be careful. Review the thread below to understand my concern.

http://www.vansairforce.com/communit...ad.php?t=62775

I now have 100 hours on my RV-4 with a Catto, 2-blade. I am very satisfied with the Catto.

2bolts 08-23-2012 02:41 PM

[quote=timothywhigginbotham;692555]
Quote:

Originally Posted by ccrawford
I have one of their props (3 blade), but ain't flying yet. The props themselves are made by Props Inc (I think). They do have a solid epoxy edge.

Quote:

Originally Posted by ccrawford

Yes, that sure looks like a Props Inc blade. Mine also had the solid epoxy edge. The blade root looks similar to the one I had also.

Please be careful. Review the thread below to understand my concern.

http://www.vansairforce.com/communit...ad.php?t=62775

I now have 100 hours on my RV-4 with a Catto, 2-blade. I am very satisfied with the Catto.

Having read that thread, I might be changing my mind about maybe trying this prop.

TXFlyGuy 08-23-2012 02:53 PM

The particular prop in question is a 4 blade 88" hydraulic constant speed prop. Wonder if that makes any difference?

rv6ejguy 08-23-2012 03:03 PM

Props are highly stressed components and like most things in experimental aviation, it is rarely a good idea to be one of the first to buy any new device on the market until the fleet has garnered a bunch of trouble free flight time. We have seen this so many times before on all sorts of components.

A prop failure can kill you and/or wreck your engine or plane. I can think of at least 6 new brands which have had catastrophic failures in the last decade. Stick to proven stuff, let someone else do the beta testing on new prop designs.

TXFlyGuy 08-23-2012 03:30 PM

Quote:

Originally Posted by rv6ejguy (Post 692568)
Props are highly stressed components and like most things in experimental aviation, it is rarely a good idea to be one of the first to buy any new device on the market until the fleet has garnered a bunch of trouble free flight time. We have seen this so many times before on all sorts of components.

A prop failure can kill you and/or wreck your engine or plane. I can think of at least 6 new brands which have had catastrophic failures in the last decade. Stick to proven stuff, let someone else do the beta testing on new prop designs.

I agree 100%! Unfortunately, my friends by default have become test pilots without any parachute. Just spoke with the owner of the company...he claims the RV-4 accident was a result of user abuse. You can be your own judge.

timothywhigginbotham 08-23-2012 08:10 PM

Owner of the RV-4
 
Quote:

Originally Posted by TXFlyGuy (Post 692578)
I agree 100%! Unfortunately, my friends by default have become test pilots without any parachute. Just spoke with the owner of the company...he claims the RV-4 accident was a result of user abuse. You can be your own judge.

I am the owner of the RV-4. Less than 2 hours on the prop when it failed. Both blades failed at the wooden blade-root. Please read the entire thread if you are considering this manufacturer.

If Jeff Bertuleit @ Props INC (or anyone else) made that statement, it's not true. He is probably referring to the RV-8 in OK that also lost a blade in-flight. The RV-8 was totaled and the owner was injured. Jeff got us mixed up repeatedly. He even sent my prop to the guy in OK by mistake. Jeff did feel one of the other props was abused because the owner planned to operate up to 3000 RPM. My prop never exceeded 2640 RPM before the event. My engine sure did when the prop came off though. Lots of damage to the valve train and other stuff.

I understand there was also a third prop that failed. At one point Jeff was being sued over this. I chose to not participate in a lawsuit. My insurance carrier indicated they may pursue damages.

I am not referring to the hub design. I have no experience with it. The wooden prop blade in the picture looks identical to the one I lost...

I had no knowledge of the other two Props INC failures before my 1st flight. I have nothing to gain or lose at this point. We don?t put the big experimental sticker on for nothing. You get to decide for yourself.


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