E-PROPS : Adjustable Pitch Propellers for engines 10-50 kW dia 115 to 160 cm

✗  Hi-Tech carbon propellers, ground adjustable pitch
✗  80 ultra-light propellers models
✗  For gear drive engines and electric engines from 10 to 50 kW
✗  Exist in 10 different diameters : from 115 cm to 160 cm, each 5 cm
✗  Available in both rotation senses : CW and CCW
✗  Tractor and pusher configurations
✗  Click to see : Traction / Torque curves of this range

✗  Very strong : blades full carbon braid, high fibers ratio, Helical Continuous Fibers, Nanostrength leading edge protection
✗  Hubs in densified wood
✗  ASTM F2506-13 certified

✗  Made in France since 2008
✗  E-PROPS production: 45.000 blades / year
✗  Sold all over the world in more than 80 countries

Ground adjustable pitch propellers are interesting for prototypes, in order to ensure the correct pitch. Once the pitch has been defined for the motorisation and the desired use, it is possible to choose the same model in fixed pitch (see Fixed pitch propellers: diameters from 115 to 160 cm), lighter and easier to assemble and disassemble.


TECHNICAL DATA

1- Blades

The blades of the range of ground adjustable pitch propellers (dia. 115 to 160 cm) are 100% carbon.


Optimum use of carbon fibers braid and epoxy resin to obtain ultra-light and very b blades.
The HCF (Helical Continuous Fibers) process, specifically designed by E-PROPS, ensures an exceptional strength of the carbon braid (like a sock) + epoxy resin blade, from leading edge to trailing edge, from blade's foot to tip.
Manufacturing process : Resin Transfer Molding (RTM).
Foam core (D-Box).
UV High Resistance epoxy resin
Very high carbon fiber ratio : 63%
See page MANUFACTURING

2- Wooden-resin hubs

For all engines up to 50 kW, rotation sense CW or CCW
For 2-blade, 3-blade and 4-blade propellers, tractor or pusher
Hub weight = 350 gr
Hub thickness = 60 mm



Material : densified wood + epoxy resin
This material has the same mechanical characteristics as some aluminium alloys, and weights 50% less that aluminium.
Mechanical strength = 277 MPa [against 280 MPa for aluminium ref 2017]. It is used for example to manufacture the insolators of the raiways, because it has a high resistance in strength, a high dimensional stability, a very good resistance to products as oil or fuel, and also a very good weather resistance.
The hub in densified wood is as strong as a carbon one.
The E-PROPS company is using this material since 2008. Those type of hubs are manufactured on a E-PROPS CNC machining center.

=> The interest of this material against aluminium : as strong as aluminium and two time lighter, easy to manufacture, cheaper.

3- Drilling

Here are the existing hub drillings patterns for the ground adjustable pitch propeller range (dia. 115 to 160 cm) :

2-blade tractor drillings :
✗  6M8d75

2-blade pusher drillings :
✗  6M8d75
✗  4M8d63
✗  6M6d50
✗  6M6d56
✗  6M6d60
✗  4M6d60

3-blade tractor drillings :
✗  6M8d75

3-blade pusher drillings :
✗  6M8d75

4-blade tractor drillings :
✗  6M8d75
✗  4M8d63
✗  6M6d50
✗  4M6d60

4-blade pusher drillings :
✗  6M8d75
✗  4M8d63
✗  6M6d50
✗  4M6d60


Explanations on drillings, see page HUBS DRILLINGS

4- Torque

The screws tightening must be done with a torque wrench; torque value depending on the screws :
Screws 6 mm = 8 N.m
Screws 8 mm = 16 N.m

5- RPM max

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

6- 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. 115 to 160 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.

7- Assembly / Maintenance

Assembly ;
[a] Get both blades, both parts of the hub and screws together.
[b] Put the blades in the hub, and the whole propeller on the engine's flange.
[c] Close the hub and make a first very slow torque of the screws.
[d] Adjust the pitch.
[e] Torque the screws as mentionned in the manual.

Maintenance :
- Before each flight: visual inspection of the propeller (particularly check the leading edge) and check the screws tightening.
- Every 50 hours of flight or every 3 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.