R&D Motor
This page is dedicated to any updates and information regarding the R&D Motor.
June 9, 2016 Motor Update
Today we had a meeting with Ed Donovan owner of R&D cable. Ed and his team are developing an electric motor that will be used on the EMG-6 electric motor glider. The design parameters are basically to design a 20 hp continuous operating motor turning at 2500 RPM and producing approximately 65 foot-pounds of torque. We will be spinning a 48 inch diameter propeller. this motor is simply a dummy motor that does not have the winding’s and magnets inside but was delivered so that we can use it for the development of the motor mounting system on the EMG 6 as both as a pusher and as a tractor on the to the wing pylon locations. The bolt pattern is the standard two-stroke Rotax engine bolt pattern. the bearing is the same as the front bearing on the Rotax E gearbox. The total motor weight will be in the neighborhood of 25 pounds when completed. There are 6 mounting locations on the rear of the motor housing. During testing at full power the outer housing gets slightly warm but the winding’s and the magnets remain cool even at full power operation. They are still undergoing some operational tests on the motor and perfecting the final design before going into the mass production phase and developing the tooling for the stamping dies for the winding core. The expectations are that the efficiency of the motor will exceed 95%.. And reliability and durability are key components in the development of the motor. I would expect that this motor will have a TBO in excess of 10,000 hours. And overhaul cost will be the replacement of 2 bearings. We have been told that we should expect to have a operational motor available for installation before we depart for the Oshkosh airshow.
December 3, 2015
The new electric motor installation is beginning to take shape. We have been working with RND and have come up with some preliminary design ideas for how were going to mount the motor on to the aircraft.
The propeller that we have in the Drawings is the design for the powerplant that we made for the Polini 250. We will be using the same diameter propeller. But not nearly as thick and heavy in the cord.
This motor is designed for 20 hp continuous output.
We still can’t divulge much about the overall motor at this point in time. But the design process is far enough along that we are going to start the manufacturing of the motor mount system.
We have designed a motor mount design that will be used for the prototype that is interchangeable with the wing mounted motor mount system as well as the fuselage mounted motor mount system.
This is a picture of the rubber isolation don’t it mounting flange bolted to the rear fairing vertical bulkhead.
For simplicity sake we have designed a motor mount system that is built out of six segments that are interchangeable and interlocking.
The segments will mount to the hub which in turn will mount to the 4130 mount shaft
On the backside of the motor mount segment you can see how the individual motor mount legs interlock.
An exploded view of the motor mount assembly.
A cross-section view
And a close-up cross-section view to see how the motor mount bolts and nuts have clearance for the propeller shaft and nut