Re: EMG-6 and Polini Engine

Good Morning Mr. Carpenter:

Wow!  Very excited about the EMG-6.  Your attention to detail has impressed me in a big way!  Two quick questions if I may.  What caused the electric engine failure in the video??  I too am more than a little concerned about RC electric motor durability.  Yuneec Corp. seems to have a handle on their motors, have you considered them?  I am waiting to see the final configuration for the Zigalo and Aeromarine as well.  I have to admit though that your airframe looks rock solid relative to the Zigalo.
 I have never trusted two-stroke engines.  So much so that it has prevented me from building and flying ultralights for the last 20 years!  I have great faith in electric  
 motor technology, but it is still evolving.  I have heard a lot of good things about the Polini Thor 250, and you seem to like it as well.  Do you think this engine is a viable
 option?  So many companies have attempted to produce a reliable/durable two-stroke and it just has not happened!  
  I hope you find the time to reply.  I look forward to hearing from you.

David E. 


The reason for the electric motor failure in the video that I’m assuming you’re referring to is related to an over-temperature of the ESC (electric speed controller) in the next video we talk about how we solved that problem, by adding a CPU cooling fan from Best Buy’s directly to the ESC controller. That solved the problem and we never did have any additional ESC problems after that point.
I don’t know if you’ve been following our blog  or not but we talked a lot about this during that time..

Keep in mind that the flight test and the development of the model airplane motor was simply a test to evaluate the aircraft performance using all off-the-shelf model airplane components. Although the use of the model airplane components keeps the airplane in the legal part 103 category at less than 254 pounds empty weight with the batteries included the use of the model aircraft motor has proven to be somewhat limited. Although were able to develop the power out of the motor fairly close to the predicted output the ability to use those high power settings is limited by the motors ability to dissipate the heat. We have found through testing that we probably can’t use any more than about 60 percent power continuously. And although that is enough power to substantially extend the flight time it doesn’t provide a power plant that would be a consumer viable component.
Keep in mind that we are working with several other engine manufacturers currently to develop modular power plant systems that can be adapted to the airframe. Most of our effort is in developing the airframe and its ability to be able to adapt these other modular motors developed by other manufacturers. We will not be developing motor technology but rather concentrating on providing a platform that can be used to leverage these other amazing new technologies being developed by other manufacturers.
I’ve included a picture of the electric motor developed by RND Corporation that we will be testing during the next series of electric motor tests.
As far as the Polini 250 motor is concerned, we continue the development of this power plant. We currently have three prototype aircraft that we are working with with different engine configurations on each. We have a total of nine customers building aircraft on their own with different desires and two of those customers are opting to go with the Polini 250 and perhaps switch to electric at a later date.
We do have quite a bit of positive aspirations for the Polini 250 but it is a new player in the two-stroke market for aircraft. It often takes many years to work out all of the small bugs but we’ve decided that the potential of that motor makes it worth our effort to continue to develop the motor installation packages for the EMG-6.
Keep in mind that the Polini 250 motor that you see flying in the videos is simply for test purposes. Our eventual goal will be to move the Polini 250 to the rear seat and be able to completely enclose the cabin and use a prop shaft out the back of the aircraft. That should substantially reduce the drag. The ability to have electric start engine on a small glider like this really offers some great potential. Be able to shut the engine off for gliding and then restart in the air.

Brian Carpenter CEO
Adventure Aircraft
Rainbow Aviation Services
N 930 Marguerite Ave
Corning, Ca. 96021
530-567-5139 cell
530-824-0644 office
530-824-0250 fax

Comments 2

    1. Post

      With the new Rex 30 motor we should have better performance than even the Polini engine. The design goals are to climb to 1000 feet and then have thirty minutes of battery remaining for cruise.

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