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VP Prop Options


Ian

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Hi Guys (and to ensure full correctness Gals too :lol: ) Thank you for the warm welcome on another thread - I said I'd have some questions so here we go:

 

There seem to be two options for a VP prop in the Flight Design price list - 80285 described as "3 Blade Variable Pitch Propellor" and 80287 "3 Blade Constant Speed Variable Pitch Propellor". Both those are in addition to 80280 "Advanced 3-Blade Ground Adjustable Composite Propellor"

 

Can anyone explain the two VP options with pros & cons please?

 

Also - as a general point, how effective is the VP prop option for the CTLS - do most of you have that option or do you fly fixed pitch?

 

Thanks

Ian

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Ian, hope that there are some here in the U.S. that have re-registered their CT's as "experimental" or some of our overseas friends who can answer your question regarding VP props. U.S. Light Sport rules don't allow use of "in flight" VP on SLSA aircraft .

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Hi Ian,

 

No one in the US has a VP prop on a CT. We aren't allowed for our SLSA aircraft. Now everyone else in the world is. Hopefully some will chime in, but with my experience with the VP prop on others it would give you the best prop settings and performance for each phase of flight. That said you couldn't go wrong with the fixed pitch prop on a CT either.

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Thanks for the replies - and there was me, a poor European, thinking you yanks were at the cutting edge of all things technical :rolleyes:

 

I've just heard back from the UK Flight Design rep to say that their standard in Europe is to include a "Kaspar VP hydraulic propeller as it’s simple and has a TBO of 1500 hours". Having been flying with a VP prop for the last 10 years I think I'd miss the flexibility and performance

 

Cheers

Ian

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Anyone have experience with the DUC Swirl or Woodcomp ProPulse propellers? They are ground adjustable propellers that have constant speed effects:

 

ProPulse

 

Propulse is the new aerolastic propeller from Woodcomp, engineered to flex under load so that it performs like a constant speed prop. Aerolastic describes the ability of structurally elastic bodies to bend or deform in response to aerodynamic loads. Under load, when the aircraft is accelerating or climbing, an aerolastic blade is engineered to deform in a predictable manner, which results in a smaller angle of attack. In reduced load conditions, at cruise, the airfoil returns to its original angle of attack. Here’s how the ProPulse performs:

 

Climbing – blades take thinner “bites”

Cruising – blades take fatter “bites”

RPMs stay in optimum torque range

Very low mass = quick acceleration

Smooth performance at all RPMs

Better climb, faster cruise, improved fuel efficiency

 

The Swirl

 

The Swirl is a simple, ground-adjustable propeller that performs like a complex constant-speed prop. It is the propeller of choice for faster airplanes.

 

The blades of the Swirl propeller are designed to adjust the effective angle of attack under differing aerodynamic loads to optimize performance while maintaining engine RPM in the optimal torque range. This is done without movement or twisting of the blades. As a result, the DUC Swirl propeller has a constant speed effect, even though the pitch is set on the ground.

 

The prop takes a slimmer bite under load, and a fatter bite when cruising, without the need for complex electro-mechanical adjustments. Thanks to this effect, there is very little variation of RPM engine between static and dynamic loads. DUC propellers perform better through the whole of the flight envelope, exhibiting:

 

Constant speed effect in a simple, not complex, propeller

Better effectiveness on takeoff and climb due to higher engine speed

Better cruise speed for a given RPM

Very smooth operating characteristics

 

I believe the Swirl has a 30 day money back guarantee that it will improve performance.

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Hi Ian,

 

I have a Neuform VP on my SW and performs well. The VP adjusted by an electric motor on top of the gear box, controlled by a Flybox from Italy. Just a pitch rotation during run-up, RPM set for T/O & landing, to add to checks. In the cruise I switch to manual and set for best performance.

 

The big difference I noticed was coming back on the throttle just after turning base, it goes fully fine in an instant, and I found I had to adjust quite quickly to maintain 70kts, same for final. I found I had to power in to maintain the magic 55kts, after that it's a breeze. Just the best thing!

 

Regards

 

Bruce

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Hi Ian,

 

I have 80285 - 3 blade Kaspar with hydraulic governor and I'm very satisfied: trouble free / simple design, almost instant action, direct feedback of prop pitch angle. Kaspar seems to be a little shorter than other props [more ground clearance] and, hmmm... very strong.

One of the BEST thing on my plane.

 

Alec

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I am considering the Ivoprop based on a friends recommendations. Comparatively Inexpensive, low inertia, constant speed option not required as it seems to me there will be much more wear on the mechanism. Apparently some Italian CT owners are using this setup

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Ian...I have the Neuform VP prop which was originally delivered with the manual hydraulic pitch control however I have since retrofitted an electric CSU comprising the electric motor supplied by Neuform and an Italian made CS control unit by Innovative Electronics.

I find the biggest advantage is when cruising in turbulent conditions whereas in the past, due to the light weight of the CT, the airplane would lose momentum very quickly and the RPM would vary as the speed increased or decreased. Now it's just a case of selecting the RPM you want and setting fuel flow with the throttle and just leaving the work to the CSU.

PR1-PCSregulator.jpg[/img]

 

CSUController01jpg.jpg

 

neuform_electric_controller__starboard_view_124.jpg

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  • 2 weeks later...

The Swirl

 

The Swirl is a simple, ground-adjustable propeller that performs like a complex constant-speed prop. It is the propeller of choice for faster airplanes.

 

The blades of the Swirl propeller are designed to adjust the effective angle of attack under differing aerodynamic loads to optimize performance while maintaining engine RPM in the optimal torque range. This is done without movement or twisting of the blades. As a result, the DUC Swirl propeller has a constant speed effect, even though the pitch is set on the ground.

 

The prop takes a slimmer bite under load, and a fatter bite when cruising, without the need for complex electro-mechanical adjustments. Thanks to this effect, there is very little variation of RPM engine between static and dynamic loads. DUC propellers perform better through the whole of the flight envelope, exhibiting:

 

Constant speed effect in a simple, not complex, propeller

Better effectiveness on takeoff and climb due to higher engine speed

Better cruise speed for a given RPM

Very smooth operating characteristics

 

I believe the Swirl has a 30 day money back guarantee that it will improve performance.

 

There is a lot of information about the Swirl prop from unfortunate buyers. Basically, it is a copy of the Warp Drive, it is of low quality, doesn't perform, isn't statically balanced. A short search on the internet and you'll find a lot about it, someone on my airfield tried it and his advice is "stay away". The manufacturer isn't standing by its product, they don't even answer emails. He asked for the 30 day money back guarantee and they said there is no such thing. They sent us their terms of trade and the guarantee is 6 months only, it's black on white. We've tried to find some information about this "constant speed effect", and it sounds like a huge marketing BS. even the manufacturer can't explain it. What we found however is customers reporting that the blades are stalling, which generates vibrations. An example of the problems you'll have with a DUC prop:DUC props on internet

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Fortunately I had a chance to compare the Kaspar VP with the Neuform VP. The Neuform VP was send to factory for inspection and during this time I mounted a Kaspar 3-Blade VP. Compared to the Neuform prop, the Kaspar was very disappointing. The efficiency of the Kaspar is much less than the efficiency of the Neuform. You can feel this at cruise flight, if you add power. The only thing what happens with the Kaspar is, it becomes louder and RPM is increasing. It feels like a slippery clutch when driving uphill.

 

 

Happy new year

 

Markus

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  • 5 years later...

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