The E-Props Company
E-PROPS DETAILS
The E-PROPS Company
195, Route de l'Aviation
ZI Aérodrome de Sisteron
04200 VAUMEILH - France

The best way to reach our team is by email : helices@e-props.fr


E-PROPS Adjustable Propellers for engines 50 - 115 kW dia 145 to 205 cm : Data Sheet


✗  Hi-Tech ground adjustable pitch carbon propellers with Titanium leading edge protection
✗  For gear-drive engines and electric motors, from 50 to 115 kW
✗  The world's lightest propellers
✗  Available in 10 different diameters: from 145 to 209 cm
✗  Each model available in 2, 3, 4, and 5 blades
✗  Exist in both senses of rotation: CW and CCW
✗  Tractor and pusher configurations; different chord widths and blade profiles
✗  Click to see : Traction / Torque curves of this range

✗  Very strong : 100% carbon, very high fibers ratio, RTM Manufacturing
✗  Carbon propellers with Titanium leading edge protection
✗  ASTM F2506-13 certified, MTBO 2.000 hours

✗  Made in Provence, France, since 2008
✗  E-PROPS production : 45.000 blades / year
✗  Propellers sold in more than 80 countries

E-PROPS ADJSTABLE TITANIUM

DATA SHEET

1 - Design
2 - E-PROPS adjustable pitch for engines 50-115 kW
3 - Ultra-light propellers
4 - Blades
5 - Carbon spacers
6 - Spinners
7 - Propellers finish
8 - Titanium leading edge protection
9 - Moment of Inertia
10 - Balancing
11 - Quality / Certification / MTBO
12 - Mechanical Strength / Load Tests
13 - Tightening torque
14 - Max RPM
15 - Max Power
16 - Maintenance


1- Design


Propellers "of 3rd generation" : efficient, ultra-light, quiet and very b.
Made in France since 2008 : see page E-PROPS company.
The secret of their exceptional performances ?
- Extensive research of the E-PROPS design department, with many tests campaigns on wind tunnel, the development of an exceptional software called (LmPTR©) and many tests mechanical campaigns (example => VIDEO : E-PROPS test campaign V20 range (April 2020)
- A manufacturing process which allows a very light weight
- Specific E-PROPS designs with high CL profiles. E-PROPS propellers design, see : DESIGN and TESTS
- Propellers with high ESR effect [Extended Speed Range] : ground adjustable pitch propellers which behaviour is very near from the behaviour of a variable pitch propeller.

2- E-PROPS adjustable pitch for engines 50-115 kW


Each E-PROPS is designed and developed for :
- the characteristics of the motor in question and its gearbox (if applicable)
- the study of engine cooling and air flow in the engine
- a defined aircraft speed range
- the aircraft configuration: tractor, pusher, high wings, low wings, and wings/fuselage interactions
- the use of the aircraft: speed, cruise, towing, STOL... and the desired performances

E-PROPS has developed numerous blade models, with several chords (C4, C8) and several profiles, in both tractive and propulsive configurations.
All of them are available in both clockwise (CW) and counterclockwise (CCW) rotation sense, in pusher and tractor configurations :
✗  2-blade models: diameters from 145 to 205 cm (every 5 cm)
✗  3-blade models: diameters from 145 to 205 cm (every 5 cm)
✗  4-blade models: diameters from 147 to 208 cm (every 5 cm)
✗  5-blade models: diameters from 149 to 209 cm (every 5 cm)

The pitch adjustable E-PROPS for engines from 50 to 115 kW all have blades equipped with Titanium leading edge protection.

3- Ultra-light propellers


E-PROPS are by far the lightest propellers in the world.
A few weighs, including screws and bolts :
- 3-blade tractor dia 170 cm Titanium for 75 kW engine: 2 kg
- 2-blade tractor dia 175 cm Titanium for 60 kW engine : 1.6 kg
- 5-blade pusher dia 172 cm Titanium for 85 kW : 3.2 kg

An ultra-light propeller has many advantages:
✗ Any weight gain is very important. This is particularly true for UAVs.
✗ A lighter propeller will increase fuel autonomy.
✗ Lighter propellers allow a better operation of the powertrain: better engine performance over the whole rpm range, better linearity in engine speeds, less jerking when starting and stopping, less stress on the gearbox, less vibrations due to propeller operation...
✗ A light propeller makes it possible to respect the maximum value of the engine's "Moment of Inertia".
✗ An ultra-light propeller is much more reactive: direct piloting, no resistance, no time lag between go-ahead and increase in speed, faster stopping, less stored kinetic energy = less damage in case of impact.

4- Blades


The E-PROPS are fully made in carbon.
Optimum use of carbon fibers braid and epoxy resin to obtain ultra-light and very strong blades.
HCF system (Helical Continuous Fibers : Fibres Continues Hélicoïdales), specifically designed by E-PROPS.
No risk of galvanic corrosion as there are no metal parts.
Very high fibers ratio : 63%
See the page E-PROPS MANUFACTURING

5- Carbon spacers


The hubs of the E-PROPS ground adjustable pitch propellers are simple and light.
They come in 3 parts:
✗  Two flat carbon parts in which the blade feet are housed, called HHU1 and HHU2.
✗  A carbon spacer that allows the propeller to be fixed to the engine, called ESU, which has a variable length according to the customer's wishes.

EPROPS HUB V20
the E-PROPS hub, an exclusive ultra-light system

E-PROPS hubs
38 different lengths: from -20 to +170 mm in steps of 5 mm

THE ADVANTAGES OF THE EXCLUSIVE E-PROPS CARBON SPACER SYSTEM

✗  Mass gain
Mass in grams of the E-PROPS carbon spacer = only 1.5 g/mm, including screws and bolts
. This is to be compared to the 20 g/mm of an aluminium spacer with screws and bolts.
Example for the extension of a 170 mm :
- mass of the carbon spacer = 170 mm x 1.5 g/mm = 255 g
- mass of an aluminium spacer = 170 mm x 20 g/mm = 3.4 kg
=> a gain of 3.15 kg !

✗  Exist in 38 lengths
E-PROPS has developed an automatic machine that takes out the spacers at the desired length.
The E-PROPS carbon spacer system is available in 38 lengths, from -20 to +170 mm, in 5 mm steps. This ensures that you will find exactly the right length for your assembly.

✗  Engine protection
If too much mass is attached to the engine, its service life is significantly reduced. Heavy propellers create a high risk of breakage.
Reducing the mass of the spacer limits this risk.

✗  Reduction of vibrations
The propeller is directly centred by the hub. This avoids spacer stacks and the various screws and pins, which often generate vibrations.
A simple and straightforward system like E-PROPS greatly reduces the risk of vibration.

✗  A reliable and durable system
E-PROPS hubs, whether standard or with spacer, are extremely strong.
Material: 100% carbon + high temperature epoxy resin
Injection according to the RTM (Resin Transfer Molding) process
Compact volume hub: for minimum drag and optimised engine cooling
MTBO 2,000 hours / Unlimited potential

✗  Simple assembly
The E-PROPS spacer allows quick and easy assembly, with the minimum number of parts.



click on the video to discover the extended hubs

6- Spinners


A complete set of E-PROPS spinners is composed of the spinner, its mounting plate and the necessary screws.
These spinners are designed for the range of tractor and pusher propellers for engines from 50 to 115 kW, diameters from 155 to 195 cm.

E-PROPS cones spinners carbon


Spinner diameter is depending on the engine cover of the aircraft.
To define the good diameter for the spinner, please take the measure "D" :
E-PROPS cones spinners carbon
measure D = max diameter of the spinner

The E-PROPS spinners exit in 15 diameters.
If you hesitate between two sizes, take the smaller, for a better air flow on the engine cover.

E-PROPS cones spinners carbon

Finish :
The E-PROPS spinners are carbon finish, shiny polished, without paint, varnish or gel-coat, because those products are very polluting.
The E-PROPS company is committed in an eco-management approach and proscribes this type of products.
The spinners can be painted. Be careful to the balancing.


7- Propeller finish


Finish with shiny polish.
The carbon braid remains visible; each blade is unique.
No paint, varnish or gel-coat, because those products are very polluting.
The E-PROPS company is committed in an eco-management approach and proscribes this type of products.
In addition, paints, varnish and gel-coat do not allow to easily repair the blades in case of impact.
Only spinners can be painted.

8- Titanium leading edge protection


The E-PROPS for engines from 50 to 115 kW with diameters from 145 to 205 cm are all equipped with 5/10th thick Titanium leading edge protection.

TITANE is the ideal material for blade leading edge protection thanks to its mechanical characteristics :
- the specific resistance of Titanium, which outperforms Aluminium and Steel.
- Coefficients of expansion and elasticity of Titanium close to the carbon-epoxy composite (material of the E-PROPS blades)
- Titanium's exceptional resistance to corrosion (especially in marine atmospheres)
- Titanium is twice as light as Steel or Inconel.
See here : TITANIUM LEADING EDGE PROTECTION

9- Moment of Inertia


The E-PROPS, ultra-light, strictly respect the Moment of Inertia limitations given the engines manufacturers.
Moment of inertia of each model calculated then verified on the tests bench.
See details here : MOMENT OF INERTIA

10- Balancing


The E-PROPS propellers are precisely balanced at workshop.
The team is using an electronic bench to balance the propellers.
More information here : BALANCING

11- Quality / Certification / MTBO


The E-Props propellers are designed, manufactured and tested to meet the requirements of the aeronautical standards.
They are ASTM F2506-13 certified (lSA standards).
No life limitation.
MTBO recommended at 2.000 hours
Quality and safety are ongoing concerns for the E-PROPS company, throughout the design, procurement, manufacturing, testing and marketing of all its products.
More information on page QUALITY

12- Mechanical Strength / Tests


E-PROPS is doing many tests on all the propellers models.
See here TESTS ON GROUND

Example => VIDEO : E-PROPS test campaign V20 range (April 2020)
Test campaign : E-PROPS propellers for Aircraft (LSA) & Ultralights, 2020 range. Tensile, bending and torsion tests.




13- Tightening torque


Tightening the fixing screws of the E-PROPS propellers must be carried out carefully, with a torque spanner, respecting exactly the torque values indicated in the Manual supplied with each propeller.
Tightening of the hub screws (M6) = 11 N.m
Tightening of the motor fixing screws (M8) = 24 N.m

14- Max RPM


The maximum rotational speed (at the propeller = maximum engine speed / reduction ratio) depends on the propeller diameter, the number of blades and the blade pitch adopted.
It is indicated on the Traction / Torque curves of this range

15- Max Power


The maximum power the propeller can absorb depends on each propeller model.
It is indicated on the Traction / Torque curves of this range

The models in the ground adjustable pitch propeller range (dia. 155 to 195 cm) are propellers suitable for reduced combustion engines and electric motors.
Do not mount these models on direct drive engines (without gearbox), excepted electric.

Warning: on electric motors, the maximum rpm of the motor very often depends on the battery voltage.
The maximum power reduces the battery voltage and therefore the maximum rpm.
This data must be taken into account to define the desired propeller model on the curves.

16- Maintenance


Maintenance is simple :
- Before each flight: visual inspection of the propeller (particularly check the leading edge) and check the screws tightening.
- Every 100 hours of flight and/or every 6 months : check of the screws tightening.
Cleaning of a carbon propeller is made with a sponge, with some water with soap, or with a product for windows cleaning.

The E-PROPS range with ground adjustable pitch, Titanium leading edge protection blades, diameters from 155 to 195 cm, have an MTBO of 2,000 hours.


E-PROPS REGLABLE PALES TITANE




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Fixed Props for engines 7-50 kW dia 115 to 160 cm
Adjustable Props for engines 50-115 kW dia 145 to 205 cm