July 19, 2016 We Receive The 3 Bladed Sterna Propeller
We received one of the propellers that we will be testing on the R and D motor. We have had extensive consultation with Sterna propellers about the propeller that would work the best on the EMG-6 with the 20 hp electric motor. We have selected a propeller blade section that will optimize the performance at a very specific profile. Mainly the ability to operate in a cruise configuration at 45 mph. We currently have 2 other propellers that are designed for the same motor that we will be testing as well. as we develop data once we begin the flight test program will use this page to accumulate information about this propeller. If the propeller works as expected we plan to offer this as one of the primary propellers for use on the EMG-6. We also plan to become an OEM dealer for the propeller and have them in stock or customers of the EMG-6. We are also working with Sterna for a propeller to be used on the Polini 250 motor as well.
I was first introduced to the Sterna propeller 2 years ago at Air Venture 2014. Sterna propellers are manufactured in China. Their footprint into the US is still somewhat small compared to other manufacturers but they are beginning to gain popularity. If you are at AirVenture, Sterna will have a booth set up and you can talk to them and see some of their other products in one of the big hangers.
Sterna propeller mounted on the aircraft
Propeller looks good mounted on the aircraft.
Un-boxing the propeller.
We like to do and unboxing review each time we get a new product
The propeller was well packed for its trip from China to the US.
Each propeller blade is shipped in its own protective sock
The propeller hub appears to be very well-designed and exhibits high quality machining. The design appears to be very well-designed with a minimal of excess material keeping the weight of the propeller very low. We have not yet weighed the propeller as we are in kind of a rush to get to Oshkosh but we will develop more data and specific numbers after return from our trip to the airshow.
Propeller hub halves
I was particularly enamored with the way that they knurled the inside of the blade hub.
Prop Hub size
The hub is a very small profile. Shown in proportion to the pencil and the mouse puts it into perspective.
I'm not quite sure of the entire makeup of the propeller blade other than it is composite. It does appear to have at least an outer layer of carbon fiber.
The fit into the hub was excellent.
Propeller blade clearance
The propeller is a 50 inch diameter propeller and it appears as though we have plenty of room to go to even a 51 inch diameter prop.
Mounting the propeller
We had to take the time to mount the propeller onto the aircraft and then remove it once again for shipping just to ensure that the fit was correct.
We're looking forward to testing the propeller once we returned from Oshkosh