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

[Garfly]

As I understand it, the CS E-prop is not yet available and the one referred to in Mark's customer's reports is a fixed one.  And a feature of these props is their light weight compared to the competition.

[Kyle Communications]

All CSU (I gather thats what your commenting on Bruce) are expensive. I personally dont think they are worth the cost for the performance for our type of aircraft.

 

Posted above is the std type ground adjustable prop.

 

I believe Eprop are finalizing testing on their range of props for the Jabiru engines now as well

 

 

[Thruster88]

3 hours ago, Bruce Tuncks said:

As well as the cost, my problem would be with the weight of the prop plus mechanism. But surely there would be an increase in the max speed, in comparison to a fixed pitch prop.

I have posted a few examples before of aircraft that have a fixed or constant speed option such as the Tecnam p2010, a 130knot aircraft. The numbers show only a small improvement in takeoff to 50 feet and slightly higher climb rate. Top speed not much difference. The Cessna 172 and piper Cherokee continue today with a fixed propellers. The Cessna constant speed version, the xp172 only lasted 3? years in the market place.

[Bruce Tuncks]

I like that story thruster. The wooden Jabiru prop is so simple and light that I would need some good figures to change for a CSU. For example, I would want about 5 knots more top speed. AND what if the extra loading by the prop caused less engine reliability?

 I have actually been worrying about this after changing from a 40" to a 44" prop on my Jabiru, I think it cruises a few knots faster and I don't notice any change on the take-off.   

[RFguy]

Bruce, apparently you get another 3 to 5 kts  with the composite jab prop on your machine... (GATHER U HAVE THE WOOD) . stiffer.

[skippydiesel]

On 21/03/2021 at 12:21 PM, Thruster88 said:

I have posted a few examples before of aircraft that have a fixed or constant speed option such as the Tecnam p2010, a 130knot aircraft. The numbers show only a small improvement in takeoff to 50 feet and slightly higher climb rate. Top speed not much difference. The Cessna 172 and piper Cherokee continue today with a fixed propellers. The Cessna constant speed version, the xp172 only lasted 3? years in the market place.

Hardly the whole story:

 

a. Hight speed - An in flight adjustable (IFA) will not improve on a fixed pitch optimised for this phase of flight.

b. Take off/Climb - An in flight adjustable will not improve on a fixed pitch optimised for this phase of flight.

 

An in flight adjustable will give you good performance in all phases of flight from short field take off to high speed cruise - this is a simple fact that can not be disputed.

 

The down side of an IFA are: Greater weight , Cost & Complexity (construction and management) - the converse is true of fixed pitch.

 

In the real world, most fixed pitch propelled aircraft owners have selected the propeller pitch angle that will best suit the range of activities anticipated for that aircraft - this is a COMPROMISE decision and will mean that the aircraft will have underwhelming performance (below its optimum) outside the selected range.

 

The aircraft T88 has exampled are generally optimised for high speed climb - that is take off distance will be good (safe) climb out good (safe) and cruise acceptable but not fuel efficient. They can be optimised for take off with further compromises and of course for high speed cruise but then take ground role will be extended (possibly unsafe) climb out will be anemic (possibly unsafe).

 

Airframe characteristics must also be taken into consideration - a draggy airframe can not be made to exceed its potential, at a given engine power (T88's examples are all pretty draggy) a heavy airframe will have a longer ground run and climb out, for a given engine power - this is just physics.

 

I like to illustrate what can be done with just a 100 hp Rotax/IFA , meticulous attention to airframe build/detail by using mention Robin Austins amazing aircraft (http://www.worldrecordplane.com/) 

 

For most RAA and lighter end of GA (sub 180 hp) the flexibility delivered by an IFA is hard to justify on economic grounds alone. If you have a need/desire to optimise your aircrafts FULL flight envelope you will have to have an IFA (& bugger the cost)

[RFguy]

indeed. for every prop and prop pitch, there is a maximum efficiency airspeed.  

[skippydiesel]

On 21/03/2021 at 12:21 PM, Thruster88 said:

...........................The Cessna constant speed version, the xp172 only lasted 3? years in the market place.

Too many years ago, I obtained my Constant Speed/Retractable Undercarriage endorsements in a Cessna 172. From aged/defective memory, it also had a 180 hp engine, significantly more powerful than the 6 & 4 cylinder variants I had flown previously . It seemed a big step up at the time, was about 10 + knots faster than its best fixed pitch/undercarriage sibling, had autopilot and other than an intermittently defective radio, was very nice (whatever that means) to fly. It cost a bit more to hire but then it was a real aircraft and worth every cent.

[Garfly]

This recent vid from France shows a SkyRanger (an old hangar queen being restored by the Easy2Fly mob) being fitted with a new E-prop.  (Auto-translate is available but not much help. You get the general idea without it, anyway.)

 

It got me wondering, Mark (Kyle), whether you have any more reports of  E-Props being used locally.    

 

 

 

Edited July 3, 2021 by Garfly

[Kyle Communications]

Hi Gary

 

I get emails from customers all the time. All very pleased with the very big improvement in performance I think I have sold about 25 or more now

 

Here are a couple of them

 

RV12 with Aeromomentum 120hp  4blade Eprop in Northern Territory

"the plane is in Alice but so far he reckons it's beautifully smooth at this stage I think we're going to have it set at around 22⁰ but will confirm, climb about 1200fpm and full speed so far is 128 at 5200 I imahine that will not change to much but that is really fast for a 12 "

 

VNE for the RV12 is 134kts !!! and he hasnt pitched it fully yet

 

 

Savannah in NZ (I have sent 3 to NZ now)

"Received  prop,thanks  very much, have  fitted  it to my savannah s set prop to 25.30 straight  and level 5650 sea level  1013 pressure, take  off similar to my keiv prop climb  out better  150 200 feet  per minute plus  as you  said 5 knots, where is best  rpm  in straight  and level  with  out compromising  take  off.very pleased so far."

 

 

Savannah in NSW

"I got my Bfr done 2day and the E-prop is a smoothness that I haven't experienced b4 and quiet.I adjusted the prop to 25.5 and seems pretty good and there's definitely a increase in speed over the Bolly. At least 5kts or more."

 

 

 

This is just a couple of them recently

 

Spoke with Anne at Eprop a couple of days ago

 

She tells me the new CS prop will be available in September after its release at a air show in France. She has my name on one to try out

 

They are still working on the Jabiru version so no date yet on it

 

 

 

[Kyle Communications]

Some info now out about the CS Eprop.

They will be released nxt month after a airshow in France. One has been put aside for me to see how they go.

Price is still flexible at the moment and will know closer to the release the actual price but currently about 11k aussie dollars. I will be trying to get a better price for sale here.

 

The whole unit inc the controller weighs only 4KG

 

 

 

https://aircraft.e-props.fr/glorieuse.php?fbclid=IwAR3qi79AFvv8sylJO8XeABsFmdhEd-rvOSB7Vcxphg51QxmXksveG8kJGks

 

TECHNICAL DATA

GLORIEUSE : 3-blade tractive propellers, full Carbon with Titanium leading edge protection, in-flight variable pitch system
For ROTAX 912S / 912iS engines
[models for ROTAX 914 and 915iS to come]
Innovative patented technology

Carbon blades with Titanium leading edge
Max power : 140 hp
Max rpm : 2.600
Available in 7 diameters : 1,60 m / 1,65 m / 1,70 m / 1,75 m / 1,80 m / 1,85 m / 1,90 m (one different mold for each diameter)
Moment of inertia : 2.600 kg.cm²

Total weight: 3-blade propeller + CS instrument + spinner = 4 kg

Electro-hydraulic control for Rotax:
✗  Configuration 2 (hydraulic equipped)
✗  Configuration 3 (not hydraulic equipped)
Max pitch / min pitch in less than 5 seconds
Safety stops min. pitch / max. pitch
Pitch variation: max. range 16°

E-SCREEN "Constant Speed" specific instrument, designed and manufactured by E-PROPS.
Version 1 : rpm adjustment potentiometer, intake pressure, tachometer, oil pressure, oil T°, water T°, battery voltage, ...
Automatic over-torque protection.
Setting via Bluetooth.
Automatic mode (Single Lever Control).
High readability screen.
Version 2 : only with potentiometer with and without scale (to come)

[Marty_d]

Done any 701's yet Mark?

 

(Very similar to early Sav I guess).

[skippydiesel]

Wow! - the lightest 2 blade CS prop that I found was about 7.5 kg. From memory the Airmaster equivalent was 9.5 kg

[Kyle Communications]

Yes but it was a 80hp one. I think he has had some other issues with the engine and hasnt flown it yet. But essentially is a Sav in characteristics.

 

Sold a stack for Savs I think 10 or 12 also  6 for P92 technams,foxbats,sonex with a rotax, RV12, Esqual,CTLS,Rans S7, 2 of WAC Spirit aircraft and others.

 

Everyone has had a quite dramatic performance improvement be it cruise and or climb...all are extremely happy. 

I think the CS may not be a big improvement on aircraft like the Sav/701 but on something more slippery it will be a big difference. I will try it on my Sav when it arrives but will probably be best on my S-21..although the Sav and the S-21 will be at least 114hp engines

 

[Kyle Communications]

Well Skippy this is a 3 blade

 

[Bruce Tuncks]

I wonder how they would go on a Jabiru motor.

[Kyle Communications]

The direct drive on Jab engines is a issue with the engine pulses directly to the prop..this is why its a been a problem developing carbon props for them. Wood absorbs the pulses

I will ask though 

I know Eprop are still testing their ground adjustable jab prop as I only asked about it a month ago.

Eprop are on holidays for 2 weeks now lucking I just had 2 props leave before they shut on friday for the holidays.

So I ont expect to hear much for the next couple of weeks

 

[skippydiesel]

12 hours ago, Kyle Communications said:

Well Skippy this is a 3 blade

 

Yes - so the weight is even more remarkable.

[Bruce Tuncks]

Thanks Kyle Coms. I was mates with the guy who tested a very early Bolly carbon 3 blade prop on his Jabiru and it lost a blade!

The pilot was lucky in that the engine stopped just before it ( the engine ) got ripped off, so his c of g was ok for the glide landing.

[Kyle Communications]

Yes I heard about that incident back then. making carbon props for any direct drive engine has been a learning curve for all the prop manufacturers. Eprop are very anal about making sure the product is perfect when released and this is why it has taken a while to get their Jab version completed. they do huge amounts of testing to make sure. They have been testing their designs now for quite a while and it has taken a long time but you can bet when its done it will out perform any other 2 blade for Jabs on the market

 

[meglin]

It would be very interesting to compare the performance of our propeller with the propeller of the same size discussed here. Starting characteristics, climb characteristics, cruising, maximum, noise, vibration. We solved the problems of using a propeller on Jabiru already 5 years ago, having developed and launched the production of especially strong blades made of pure carbon fiber.

Edited August 12, 2021 by meglin

[Kyle Communications]

This was a long time ago about the incident above. Bolly were trying to develop a all carbon 2 blade for the Jabs. They have it solved now. The Eprop one is still in testing but not too far from being released. There is a airshow in France next month that Eprop is releasing the CSU version so maybe it maybe released there as well

 

[meglin]

It is also worth comparing the strength and stiffness of the blades due to the fact that most aircraft with pulling propellers have critical clearance indicators, and the propeller, even with careful operation, always gets grass, sand, and stones.

[RFguy]

Vladimir,  thanks for your posting here, most interesting  !

 

I will check out your website.

 

regards,

glen

 

[skippydiesel]

Hi Kyle - any photo detail  of the new CS prop ?