Cooked Motors

[Barf]

Hi All.

I have the Eco 8 using 8 2ah cells and find that the motors are cooking with the heli not even getting off the ground. I am using a carbon fibre training undercarage.

I have tried a 16 turn triple wound car type motor and a Kyosho K Speed heli motor. The Kyosho motor actually melted the solder and plastic brush housing.

Any ideas? BTW: I can't afford a brushless setup!

Regards Steven.

[mila]

Hi Barf,

I have been using a car type motor LRP GT 1 23x2 (modified for reverse turn), 10 t pinion, 8x 1,700 mAh with no problem.

Two points to consider:
gear ratio - are you using 10 t pinion
timing of the motor - is this correct

Now I have GM racing AIR 2000 (=Ikarus Performance) and 9*1,700 mAh - seems to be very good combo for a HELi beginer.


My Eco 8 pages (now in Czech only) http://www.multiweb.cz/elektrolety/eco.htm



[This message has been edited by mila (edited 08-07-2000).]

[Tohru Shimizu]

Hi,

I also think that 20-23turn RC-car motor is suitable for your ECO8. The pinion gear will be 10-12T.

Less teeth gear is low power (= kind for the motor), and vice versa. In addition, if you don't want more power, you may use 7cells for the motor with 10-14T.The life time of the motor becomes longer than the case of 8cells.

Note that in many of cheap motors, the motor timing cannot be changed. Since ECO8's gear unit requires the rev. direction opposite to normal RC-cars, the motor timing may have to be adjustable.

[mila]

Hi,

Just to note LRP GT 1 is a stock motor, i.e. the timing may not simply be changed. I had to modify the motor (open the motor - change timing -close it and drill two holes for screws M2 - 20 minutes). I had big problems with bushing on LRP GT1 - I had to replace them with ball bearings.

[Barf]

Thanks for the replies guys.

The problem is sorted out. I am using a 25 turn motor with around 16 degrees advanced timing. At last it gets into the air, that battery is lightly warm and the motor is only warm!

The problem I had tonight was that when I got the heli in the air it was moving like a top. It wasn't spinning (the tail rotor is doing it's job) but each leg was dropping in turn. If you can understand what I mean!

I wouldn't have thought the training gear would be very far out of balance.

Regards,
Steven.

[ericpa]

Steven

The gyrations you describe "spinning like a top" are most likely due to too low a head speed. Increase your head speed either by changing gear ratio (use a pinion with more teeth) or perhaps you have too much pitch on before the motor is running fast enougth.

Either will result in low head speed and the sort of behaviour you are experiencing

Eric

[Barf]

Thanks Eric!

I bought a JR 652 radio and am using the pitch/throttle mixing and that has helped alot. It isn't completely gone but at least the heli is controlable now :-)

I have ordered a couple of pinions as my motor and battery are only lightly warm.

Thanks,
Steven.

[Gustavo]

Hi,
Try to buy in towerhobbies, this motor Kyosho Magnetic Mayhem Reverse (22turns-single), is very cheap (about $30) and Eco fly very well, also this motor work good with low temperature (13T pinion). I use with Ikarus Heli 4000 Speed Control. I will replace bushing in this motor with ball bearings to improve performance...

Now, I fly my Eco with X-250-6 Brushless, but from time to time (to rest brushless motor), I replace with my Kyosho MM and hover is good. One advantage of my brushless over Kysoho MM is the flight time (about 15 min with brushless X-250-6 and only 6min with Kyosho MM)

Bye.

[Richard Fry]

I've been using the Magnetic Mayhem Reverse motor on the 10 tooth pinion for a few months now, and everything is working 100 percent. I have got a 13t pinion, but have not tried it yet - if it ain't broke then why bother fixing it??

Batteries are Sanyo 3000's (10 of them) and give flight times of up to 13.38 minutes.

[mila]

Just for inspiration:

The propeller is from "Air Freshener" which is used in cars. http://www.heliservis.cz/images/chlazeni.JPG
Please note that the fan blows up - the author says, it is Ok and moreover the dust from bushes is not in the motor !

I am using a similar fan, but built from balsa and plastic for opposite rotation.

[joe]

my heli spun like a top on its first flight because the gyro was in upside down.
after fliping it 180 derees it worked fine
Crazy Joe

[Kevin Murray]

Gustavo, What cells and how many are you using for the 15min times ?
Also dose your brushless motor have a 5mm shaft ?
What pinion ?
.

[Gustavo]

Kevin, I use 10 Sanyo cells of 2400mah with 18T Pinion in this X-250-6 brushless motor (5mm shaft)
The flight time is long and OK, but this motor is powerless... only for normal hover... in fact I will return this motor to Ikarus because I made my original order of X-250-4 (acro capable), and Ikarus send to me this X-250-6 without notifications.

I tried this motor (X-250-6)with 8 cells even with 22T pinion and the Helicopter no had power to lift up!

Gustavo.

[Hawaii]

I also got this motor, but it came with a 14 tooth gear. I haven't finish it yet, but will post results next week.

[Hawaii]

Got my ECO 8 finished. But it wouldn't fly, I use 8 cells and the X250-6 motor, 14 tooth pinion gear and 40 tooth tail rotor. The Heli will turn left with full right rudder, I think the tail rotor gear is mismatched. THis motor has lower rpm than the X250-4H according to the spec sheet. I wonder why Ikarus replace the X250-4h and replace it with X250-6 and still use the 40 tooth tail rotor gear.

[Kevin Murray]

Hawaii it sounds as if the tail rotor belt may have been twisted the wrong way.
And I think there was a quality and lifespan problem with the X250-4H, so they are shipping the next best thing.

[Gustavo]

Hawaii,
It happened to me the same with 8 cells and 14T pinion!!. To lift up Eco 8 with this powerless motor (X-250-6) try with 18T pinion and 10 cells. This is the only way that I find to lift up Eco 8 with this motor... For that reason I returned to Ikarus.

[Hawaii]

Thank you everybody, My Eco8 with the X250-6 lifted off the ground and hovered for 10.5 minutes on 12 cells of 3ah Nimh cells. The performance was better than the Voyager E or the Concept SR and the flight time doubled. THE heli hovered at 1350 rpm and stop flying at 1100 rpm. The temperature of the motor after the Flight was 60 degree C. I guess for inverted flight, I will need maybe a 16 or even 18 tooth pinion gear. The total weight was 1700 g, without the battery it weight 915g, lighter than the Concept Sr AND Voyager E with standard servo 1005g, 1165g. This ECO 8 with the Brushless motor and V45 controller sells for less than US400, It is a better buy than the Voyager E with a brush motor.