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E-Props ...who has first hand experience with these


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Hi all,

I am building an ICP Savannah S and I am leaving no stone unturned looking at the best motor, propeller and/or instruments.

 

A few times now, I have come across the possibility of using an E-props propeller. Two interesting articles of actual testing with Savannah S aircraft are attached below.

 

Does anyone else have actual E-props experience on aircraft they have flown and/or own?

Savannah_eprops_2017-ENG.pdf

epropsVSduc.pdf

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Gday, Finally the results of testing the EProp in comparison to Bolly and Kool (Luga), using manifold pressure to set engine power exactly equal for each. Once again surprising results that

Haha....Different aircraft. Got a 70+ inch two blade Sensenich on it. When you pull the throttle back to idle, you can just drop the nose and descend over 1500fpm and stay below Va.

Skippy what Blue is talking about in the pitch is as I said you get a suggested starting point for your type of aircraft. That pitch setting is nothing like you have seen before with any other prop. W

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Hi all,

I am building an ICP Savannah S and I am leaving no stone unturned looking at the best motor, propeller and/or instruments.

 

A few times now, I have come across the possibility of using an E-props propeller. Two interesting articles of actual testing with Savannah S aircraft are attached below.

 

Does anyone else have actual E-props experience on aircraft they have flown and/or own?

I have 232 hours behind a DUC and their great holding up excellant. Their time in service is 800hrs. All composite. E-props are a newer design and have great reports. They are a good resin mix and in about 15 months I’ll buy one. Good to see and Australian rep coming on line. l’ll keep the DUC as a spare as it will be at 1/2 to 2/3 life.

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Well hopefully in about 2 or 3 weeks I will be able to give you some real data on them Hank. The recommended model is the DUR-3-175-C ...I have the 120mm spacer backplate and 260mm spinner coming. Also a std no extension backplate. My mate danny wants it on his Sav straight up as he has been chasing vibrations in his . he has tried his bolly and a warpdrive..there is a little difference between them but all reports say this prop substantially reduces vibration due to it being so light

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I had a very bad experience with Duc props and their rep in NZ at the time and French manufacturer

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Hi, I have been flying for about 7 months with my 4 blade e-prop fitted to a SeaRey. I honestly could not be happier. Performance improved dramatically over the IVO prop that I had on before. As an added bonus the vibration that I used to think was normal has completely disappeared. I gained about 7knots speed (a big deal in a SeaRey) and it climbs 300 ft/ min better.

Worth every extra cent that they cost in my opinion. They look a bit flimsy - but it's handled water operations without a mark. They are certainly a lot tougher than they look.

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Hey thanks for the report...you are the only one so far I have heard of here in OZ that has a E-prop...pushers are recommended to have multiblades same as the trikes

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Less clean ( not slippery) planes, need more dense props. ie More blades or wider blades (If you want to go a bit higher also). Nev

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Hi Eighyknot,

 

Sorry no experience with E-Props. Have had a look at their web site. very well presented. Great claims always make me wary.

 

Any more than 2 blades, on a small aircraft propeller, also make me think style over function (unless clearance is an issue).

In my training/experience & reading, 2 blades are the most efficient, tend to be lighter, easier to "tune" (pitch, static & dynamic) and cost less to purchase - all objective easy to verify observations.

Three blades may, in certain circumstances, give better initial acceleration and therefor shorter ground role, some say are smoother (less pulsing) in operation and of of course a lot think look much sexier looking - tend toward subjective, hard to verify points.

 

The Rotax 912/914 range has a relativly slow prop speed (thanks to the g box) and I feel (not much evidence) that comparatively broad blades are likely to give better results in this context..

 

My RAA experience is mostly with Rotax 912 ULS driving a FITI 2 blade prop (they also have an optional 3 blade). Once I had done a painstaking static balance, pitch adjustment, followed by a professional dynamic balance, I had an astonishingly smooth quiet propeller that could easily pull my aircraft to over 120 knot indicated (sea level) and cruise all day at 4800-5000 rpm, 100-110 knots, 13-14 L/hr.

 

I am not actually trying to promote Fiti just pointing out that there are other well performing props "out there" and you should be wary of extravagant claims of performance gains.

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Hi Eighyknot,

 

Sorry no experience with E-Props. Have had a look at their web site. very well presented. Great claims always make me wary.

 

Any more than 2 blades, on a small aircraft propeller, also make me think style over function (unless clearance is an issue).

In my training/experience & reading, 2 blades are the most efficient, tend to be lighter, easier to "tune" (pitch, static & dynamic) and cost less to purchase - all objective easy to verify observations.

Three blades may, in certain circumstances, give better initial acceleration and therefor shorter ground role, some say are smoother (less pulsing) in operation and of of course a lot think look much sexier looking - tend toward subjective, hard to verify points.

 

The Rotax 912/914 range has a relativly slow prop speed (thanks to the g box) and I feel (not much evidence) that comparatively broad blades are likely to give better results in this context..

 

My RAA experience is mostly with Rotax 912 ULS driving a FITI 2 blade prop (they also have an optional 3 blade). Once I had done a painstaking static balance, pitch adjustment, followed by a professional dynamic balance, I had an astonishingly smooth quiet propeller that could easily pull my aircraft to over 120 knot indicated (sea level) and cruise all day at 4800-5000 rpm, 100-110 knots, 13-14 L/hr.

 

I am not actually trying to promote Fiti just pointing out that there are other well performing props "out there" and you should be wary of extravagant claims of performance gains.

We had a FITI spin one blade in its hub (3 blade configuration) up here recently, waiting to find out why; all props can have issues on hopefully rare occasions.

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Totally different aircraft Skippy

The sav is not a slippery light carbon glass machine. As Hartzell say below its thrust that makes you go up. Props are also pitched for takeoff or cruise and perform very differently. Its voodoo stuff really. All you can hope for is to get a prop that does your mission acceptably

 

In real terms there is very little difference in efficiency between a 2 and 3 blade propeller as stated below

 

Until we get to do a real world test its all conjecture. I was recommended these props after extensive testing of all different propellers on Savannah aircraft. This is now the standard fit for them by this company. Even if the performance increase is only slight the main advantage seems to be the vibration level straight out of the box without all the adjusting you have done. The noise of the prop as well. The bolly that seems to be on a lot of the savannahs that I know is just a average prop and no world beater. I have flown a rotax powered S-21 which had the 75inch Whirlwind Stol prop (very expensive here) that was certainly at least at 600kg and it went pretty well. I doubt very much a Bolly would have produce the same performance.

 

I am fully aware of claims that seem to good to be true but if you go through all of those literally hundreds of testamonials on the site its pretty hard to find anyone who does not really like the prop for whatever reason and this is spread across a hell of a lot of different style aircraft.

 

Will know soon enough when it arrives

 

 

 

 

 

From Hartzell

 

Efficiency

 

In general, 2-blade propellers are slightly more efficient. However, efficiency doesn’t propel an airplane, thrust does. Thrust is needed to overcome drag and weight, helping the aircraft climb.

 

Choosing the right number of propeller blades depends on certain parameters, including a given aircraft’s engine power, operating RPM for the propeller, diameter limitations, and performance requirements. If these factors are held constant, the efficiency of a propeller would decrease as more blades are added. However, as engine power increases, additional blades are generally required to efficiently utilize the increased power and produce thrust. Therefore, the most efficient number of propeller blades for an aircraft depends on the combination of these factors, which of course, will vary depending on the aircraft.

Noise reduction and cabin comfort

 

Cockpit noise can come from many sources, including the engine, exhaust system, airflow around the fuselage, and the propeller. High levels of cabin noise can cause stress and pilot fatigue, and may even lead to hearing problems among pilots. Increasing the number of blades on a propeller is one solution to reducing cabin noise. In most installations, increasing the propeller blade count also reduces noise. This is largely due to a reduction in vibration.

 

In a single-engine aircraft, the propeller blade wake beats on the windshield and produces cabin noise. A 2-blade propeller produces two pressure pulses per revolution, whereas a 3-blade propeller will produce three smaller pulses per revolution for the same amount of total thrust. As a result, the 3-blade prop will be inherently smoother and therefore quieter. In general, the 3-blade propeller will have a smaller diameter than the 2-blade propeller that it replaces, which also serves to reduce the tip speed and noise. In a twin-engine aircraft, the reduced diameter of the 3-blade propeller will result in less tip-generated noise and a greater clearance between the blade tip and the fuselage. Vibration is not only noisy, but it can also cause discomfort and potentially damage avionic systems. Adding more propeller blades can help reduce vibration, improving overall cabin comfort for pilots and passengers.

 

At Hartzell, we have over 400 different propeller blade designs available, which can be configured in hubs with 2-blade through 6-blades. We’re happy to help you find the right propeller system for your aircraft. To find a propeller specific to your aircraft and engine/airframe combination,

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Well hopefully in about 2 or 3 weeks I will be able to give you some real data on them Hank. The recommended model is the DUR-3-175-C ...I have the 120mm spacer backplate and 260mm spinner coming. Also a std no extension backplate. My mate danny wants it on his Sav straight up as he has been chasing vibrations in his . he has tried his bolly and a warpdrive..there is a little difference between them but all reports say this prop substantially reduces vibration due to it being so light

 

Great!

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Totally different aircraft Skippy

 

I agree Kyle - no question, the prop should be matched to the aircraft (that is engine/air-frame combo) but like most of the contributors to this forum, over time we have seen so many claims from propeller/aircraft makers that turned out to be everything from true (the minority), slight exaggeration, massive BS, to down right terminological fabrication.

 

 

I am fully aware of claims that seem to good to be true but if you go through all of those literally hundreds of testamonials on the site its pretty hard to find anyone who does not really like the prop for whatever reason and this is spread across a hell of a lot of different style aircraft.

 

The problem with this statement is neither of us know what censoring has occurred and you have not taken into account the perfectly human tendency to positively reinforce your (purchase) decisions by making positive /affirming statements about the same.

 

I am not suggesting there is anything wrong with the E-Prop - more than likely a perfectly good piece of machinery BUT does it deliver the improvements OVER OTHER PROPS that it's makers/sellers suggest ????

 

Will know soon enough when it arrives

 

 

From Hartzell

 

Efficiency

 

In general, 2-blade propellers are slightly more efficient. However, efficiency doesn’t propel an airplane, thrust does. Thrust is needed to overcome drag and weight, helping the aircraft climb.

What is this bit of BS ?? the corollary of this statement would seem to be that an inefficient prop that somehow delivers the required thrust (magic) is acceptable/desirable.

 

Choosing the right number of propeller blades depends on certain parameters, including a given aircraft’s engine power, operating RPM for the propeller, diameter limitations, and performance requirements. If these factors are held constant, the efficiency of a propeller would decrease as more blades are added. (would seem to contradicts the lead statement above) However, as engine power increases, additional blades are generally required to efficiently utilize the increased power and produce thrust. (for the most part we are in RAA - not applicable) Therefore, the most efficient number of propeller blades for an aircraft depends on the combination of these factors, which of course, will vary depending on the aircraft.

 

Of course this statement is correct IF you happen to be making an academic observation about all propeller aircraft BUT we are predominantly discussing relativly low powered aircraft, in the recreational/light GA area, so concepts around increasing power and the number of blades required to harness this increase within a given swept arc is right outside our league.

 

With the exception of reduced clearance or very high prop speed applications ( cant imagine what hes might be) I stand by my training, reserch and practical experience - there is little if anything to be gained by a 3 blade prop in RAA, other than the efficiency gained by carrying a lighter wallet.

 

Noise reduction and cabin comfort

 

Cockpit noise can come from many sources, including the engine, exhaust system, airflow around the fuselage, and the propeller. High levels of cabin noise can cause stress and pilot fatigue, and may even lead to hearing problems among pilots. Increasing the number of blades on a propeller is one solution to reducing cabin noise. In most installations, increasing the propeller blade count also reduces noise. This is largely due to a reduction in vibration.

 

In my limited experience metal (spam cans) air-frames are very much noisier than wood, fabric or composite. Want a quieter RAA aircraft check out the alternative (to metal) builds.

 

In a single-engine aircraft, the propeller blade wake beats on the windshield and produces cabin noise. A 2-blade propeller produces two pressure pulses per revolution, whereas a 3-blade propeller will produce three smaller pulses per revolution for the same amount of total thrust. As a result, the 3-blade prop will be inherently smoother and therefore quieter. (wild statement) In general, the 3-blade propeller will have a smaller diameter (supposition) than the 2-blade propeller that it replaces, which also serves to reduce the tip speed and noise. (Rotax 912/914 props are already slow compared with LyCons & Jabs not saying tip speed is not a factor just that it is relativly lower down the noise generating ranking) In a twin-engine aircraft, the reduced diameter of the 3-blade propeller will result in less tip-generated noise and a greater clearance between the blade tip and the fuselage. (Not applicable in our world) Vibration is not only noisy, but it can also cause discomfort and potentially damage avionic systems. Adding more propeller blades can help reduce vibration, improving overall cabin comfort for pilots and passengers. (another wild statement with but a shred of logic to underpin it)

 

At Hartzell, we have over 400 different propeller blade designs available, which can be configured in hubs with 2-blade through 6-blades. We’re happy to help you find the right propeller system for your aircraft. To find a propeller specific to your aircraft and engine/airframe combination,

 

Most of your Harzell quote has little or no practical application in the RAA world and probably only starts to have real meaning in singles above 200 hp (just a guess).

 

My guess - your Hartzell quote was generated or massaged, by the marketing/sales people - not much engineering in it.

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That was straight from Hartzell's page...( Not a guess).. One would think they know a lot more than you and certainly me

If you do some searching you will find its the same as 99.9% of info available out there from all sources about prop efficiency in its simplist form. The more intricate details are way above my brain

Numbers are what I like...real numbers after tests. Thats what I do every day

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Hi all,

I am building an ICP Savannah S and I am leaving no stone unturned looking at the best motor, propeller and/or instruments.

 

A few times now, I have come across the possibility of using an E-props propeller. Two interesting articles of actual testing with Savannah S aircraft are attached below.

 

Does anyone else have actual E-props experience on aircraft they have flown and/or own?

 

Hi 80 knots glad to see you have seen the light and picked the best aircraft :)

I have done a bit of prop playing and the Savannah s has 125mm prop Extension which changes the ball Game on prop choices . The lighter the prop the better for engine and gearbox life when you have a prop extension . If you had to pick a prop that wouldn’t break up inflight after a bird strike warp drive the only one however very heavy and lacks performance . I can’t wait to try a EProp and what I have seen and read so far It sounds the Best fit for a Savannah . It looks to solve a lot of problems of the prop extension which no other prop manufacture has over come . They have seen the light and have used a thin blade design to over come the drag of a 3 three blade on a 100 hp engine . I could bull shit for hours on props but it comes down to have the right pitch on prop for cruise but still have enough slippage of prop to get enough revs to take of and climb . As you aren’t a car with a multi speed transmission But you have a bigger speed range then most cars . Hoping to get a eprop with in a month to try .

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Totally different aircraft Skippy

The sav is not a slippery light carbon glass machine. As Hartzell say below its thrust that makes you go up. Props are also pitched for takeoff or cruise and perform very differently. Its voodoo stuff really. All you can hope for is to get a prop that does your mission acceptably

 

In real terms there is very little difference in efficiency between a 2 and 3 blade propeller as stated below

 

Until we get to do a real world test its all conjecture. I was recommended these props after extensive testing of all different propellers on Savannah aircraft. This is now the standard fit for them by this company. Even if the performance increase is only slight the main advantage seems to be the vibration level straight out of the box without all the adjusting you have done. The noise of the prop as well. The bolly that seems to be on a lot of the savannahs that I know is just a average prop and no world beater. I have flown a rotax powered S-21 which had the 75inch Whirlwind Stol prop (very expensive here) that was certainly at least at 600kg and it went pretty well. I doubt very much a Bolly would have produce the same performance.

 

I am fully aware of claims that seem to good to be true but if you go through all of those literally hundreds of testamonials on the site its pretty hard to find anyone who does not really like the prop for whatever reason and this is spread across a hell of a lot of different style aircraft.

 

Will know soon enough when it arrives

 

 

 

 

 

From Hartzell

 

Efficiency

 

In general, 2-blade propellers are slightly more efficient. However, efficiency doesn’t propel an airplane, thrust does. Thrust is needed to overcome drag and weight, helping the aircraft climb.

 

Choosing the right number of propeller blades depends on certain parameters, including a given aircraft’s engine power, operating RPM for the propeller, diameter limitations, and performance requirements. If these factors are held constant, the efficiency of a propeller would decrease as more blades are added. However, as engine power increases, additional blades are generally required to efficiently utilize the increased power and produce thrust. Therefore, the most efficient number of propeller blades for an aircraft depends on the combination of these factors, which of course, will vary depending on the aircraft.

Noise reduction and cabin comfort

 

Cockpit noise can come from many sources, including the engine, exhaust system, airflow around the fuselage, and the propeller. High levels of cabin noise can cause stress and pilot fatigue, and may even lead to hearing problems among pilots. Increasing the number of blades on a propeller is one solution to reducing cabin noise. In most installations, increasing the propeller blade count also reduces noise. This is largely due to a reduction in vibration.

 

In a single-engine aircraft, the propeller blade wake beats on the windshield and produces cabin noise. A 2-blade propeller produces two pressure pulses per revolution, whereas a 3-blade propeller will produce three smaller pulses per revolution for the same amount of total thrust. As a result, the 3-blade prop will be inherently smoother and therefore quieter. In general, the 3-blade propeller will have a smaller diameter than the 2-blade propeller that it replaces, which also serves to reduce the tip speed and noise. In a twin-engine aircraft, the reduced diameter of the 3-blade propeller will result in less tip-generated noise and a greater clearance between the blade tip and the fuselage. Vibration is not only noisy, but it can also cause discomfort and potentially damage avionic systems. Adding more propeller blades can help reduce vibration, improving overall cabin comfort for pilots and passengers.

 

At Hartzell, we have over 400 different propeller blade designs available, which can be configured in hubs with 2-blade through 6-blades. We’re happy to help you find the right propeller system for your aircraft. To find a propeller specific to your aircraft and engine/airframe combination,

Mark there are many out there in service, so any issues will show their heads and they have not to date. Also they are on a variety of airframes and configurations. They are in my opinion a step forward from the DUC and therefore the ‘F1’ grade of propeller. A big part of their apparent success will be the resin type used as there are some brilliant developments in the resin areas that are so strong and abrasion resistant in very thin layups. I have been seeing this first hand in non aviation areas. The carbon fibre is a lesser contributing factor to the design success. I reckon they are worth investing in and anyone buying one will be delighted. As I have said I had planned to get one July next year many months ago. I would get one tomorrow if my budget allowed.

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Hi 80 knots glad to see you have seen the light and picked the best aircraft :)

I have done a bit of prop playing and the Savannah s has 125mm prop Extension which changes the ball Game on prop choices . The lighter the prop the better for engine and gearbox life when you have a prop extension . If you had to pick a prop that wouldn’t break up inflight after a bird strike warp drive the only one however very heavy and lacks performance . I can’t wait to try a EProp and what I have seen and read so far It sounds the Best fit for a Savannah . It looks to solve a lot of problems of the prop extension which no other prop manufacture has over come . They have seen the light and have used a thin blade design to over come the drag of a 3 three blade on a 100 hp engine . I could bull **** for hours on props but it comes down to have the right pitch on prop for cruise but still have enough slippage of prop to get enough revs to take of and climb . As you aren’t a car with a multi speed transmission But you have a bigger speed range then most cars . Hoping to get a eprop with in a month to try .

Hope to read some results when you have got it. Such promises make me sceptic, but their way to look at it impresses me.

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Hope to read some results when you have got it. Such promises make me sceptic, but their way to look at it impresses me.

 

I am somewhat skeptical about manufacturer's claims too, especially without any backing of real world experience. That is why I was happy to read about actual comparison results with a draggier aircraft such as the Savannah S (see the attachment in my first post).

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That was straight from Hartzell's page...( Not a guess).. One would think they know a lot more than you and certainly me

If you do some searching you will find its the same as 99.9% of info available out there from all sources about prop efficiency in its simplist form. The more intricate details are way above my brain

Numbers are what I like...real numbers after tests. Thats what I do every day

 

Hi Kyle - No offence intended but that quote from Hatrzell was/is 90% marketing, 8% fact and 2% application(% figuration) to RAA & the smaller end of GA - just my opinion of course. By the way having flown behind Harzell props (fixed & CS) I have no problem with their product(s)

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For everyone's information, I was on the phone to Airmaster in Auckland yesterday and they do not support E-props blades. They do support Bolly, Whirlwind, Warpdrive and Sensenich.

 

Most likely this is because E-props propellers do not need an Airmaster system due to the ESR effect (Extended Speed Range effect).

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Hank I think you will find it is because the E-prop blades are quite thin so dont have the "paddle" type blade. On the airmaster of course you can play with the pitch inflight to suit. I believe though E-prop are working on a IFA..I would imagine they may use a different design blade

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Hi all,

I first used a Eprops 3 years ago..on a Savannah .

5600 on takeoff 5500 on climb 5600 full power level flight

VERY smooth and low inertia at engine stop .

After, I ordered mine for my CT ,but first used it on a CH601 .

More efficient than the Warp Drive previously installed, a bit better than the Kiev , .

Ii recommended on our 'CT forum' and you can read all the comments here

 

http://ctflier.com/topic/4988-new-propeller-for-ct/?tab=comments#comment-73293

read my 'report' about the test results on the amphib Kitfox

much more efficient than the Whirlwind.

 

alos, sold one to a customer for his SkyCruiser....replacing his Sensennich...

 

so, far,, everybody is happy, and nobody used the ''6 months satisfied or return ''

 

my 2 cents

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