ggcrandall1

Does anyone know if you can run two brushless motors from one brushless ESC?

There is a company called Model Airplane Engineering (M-A-E) that does it with a Thunderbird-9 and two CD-ROM motors. However I thought I have read/heard that you cannot do this.

I am thinking about getting a twin like the TwinStar and would use something like a pair of AXI 2808's and a Phoenix-45. I am concerned that if two ESC's are used one could shut down it's motor while the other still runs. I have never flown a twin but have heard about the problems associated with single engine operation.

If single ESC operation is not feasible does anyone know how to insure that both motors stop at the same time?

Thanks, Glen

geno472

Hello, I was told by the Hacker Brushless rep that you can not run two brushless motors on one ESC, however I do not remember his reasoning. We have a person in our local club that recently finished a 40 twin DeHaviland Mosquito and on his maiden flight he lost one whole prop and hub assy. Amazingly the airplane flew just as well with one motor as it did with two! Of course it flew slower, but it flew straight, required very little rudder input and he flew it around for another five minutes to trim it out so he could land, and he landed just fine. We were also under the impression that if you loose a motor on a twin that it is almost impossible to recover, but after talking to other guys in our club who have had single motor failures on electric twins they were also able to recover uneventfully. It does not seem that the same torque effect that applies to glow or gas engines applies to electric motors or maybe it is just not as drastic as a glow/gas engine. I would say go for it and if all else fails and you loose a motor just throttle back the other one and land deadstick. Just MHO.

Gene

RGN01

I can't find the email but I asked Castle Creations this question and they said it could be done but is not recommended because the controllers sense the motor speed, direction etc. and two motors on one ESC create confusing signals. It should work but efficiency is down.

I'd set both ESCs to soft shutdown where they simply reduce power rather than shut the motor down completely. It will still give differential thrust but it won't be as bad as one motor dying completely! ALso, test run it on the bench first - I think you may be surprised just how close the ESCs will be when it comes to shut down.

Hope this helps.

Richard

ULTIMATE LVR

My Feedback: (49)

The info is correct from CC, but I would go one step further and say just dont do it. The problem is if you shut the motors down in flight, one may not start again. The brushless speed controllers control the timing of the motor among other things. If the timing sequence is not exactly the same for both motors, only one will run. What I did on my zagi is to run one battery that can handle the combined amp load of the motors. Plug both SCs into it with a "y" harness. If the BEC is set the same for both SCs, you should not have any problems with one motor shutting down before the other.

Just my $0.02.

ggcrandall1

Thanks for the help guys. I will try the "y" harness idea.

Glen

RodgerPM

How did it work? I just built a P38 using two KMS18 Speed controlers. I found that I had to disconnect one of the SC's from the Y harness or just one Speed controller ran both engines and the other ignored everything. However the plane flew well in both cases. I was thinking of going to Castle Pheonix 25's as they are not automatically sensing the batter and engines and have the soft shutdown. I was also thinking of one ESC for the two brushless motors and found this thread while searching for a solution before I spent more $$$. The Plane flies extremely well (stable anyway haven't tried any acrobatics yet) and I'd love to keep it going. Two others are building a version of my plane already here in town and the dual motors are the biggest concern for all of us.