Ok, I got my brushless setup, I have some questions: - RC Groups
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May 24, 2001, 04:23 PM
Registered User

Ok, I got my brushless setup, I have some questions:


Info:
Ikarus ECO-8
HAcker B40-9L heli
Kontronik Smile 40-6-12
7 Sanyo 2400 mAh cells


I know that a lot of you don't run 7 cells, but with (X) cells, what pinion(s) do you use?

Also, does the governor mode really require a separite "slider" channel like the instructions say?

I am now using the "motor-plane" mode with a totally linear throttle/pitch curve.


Thanks all

PS. Just with the 10 tooth pinion I got almost 2 minutes extra run time... yeah.
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May 24, 2001, 04:57 PM
1.21 Gigawatts!
Steph280's Avatar
Don't know about pinion on Eco since I am running Voyager. But I did notice I have to increase tooth count when I switch to brushless. I am running 17 right now, will try even higher count.

the slider channel is not required. You can have you throttle curve set to 0,50,50,50,50 which is like turning the knob/slider to 50%. Problem with that is you have to make sure you don't back down your throttle all the way while flying. If your motor stops, it takes few seconds to get back up to speed.

I haven't tried the regular mode on my Smile yet. Supposedly the governor mode consumes more amp.
May 24, 2001, 09:32 PM
Registered User
>with (X) cells, what pinion(s) do you use?

The gear ratio is X(cells)*1.1(Volt)*3333(KV)*0.9/(rpm). The rpm is for the main rotor at the appropriate max pitch (9-13deg). The "0.9" is roughly the safe load rate for Neodyum magnet motor.

Therefore, if you assume 1300rpm for 7cells, the gear ratio becomes 17.7:1. The pinion gear becomes 180/17.7=10T.

For 8cells, it becomes less than 10T but the gear is not available in ECO8. With 10T,the rpm increases to around 1400-1450rpm. The flight becomes powerful and short duration.

10cells evidently results in overload. Cannot be recommended. Or, short duration (1-2min) only will be OK.

Inversely, 6cells3000mAh will result in longer duration flight with 10T (,if it can lift off).

[This message has been edited by Tohru Shimizu (edited 05-24-2001).]
May 25, 2001, 08:35 PM
Registered User
Thank you, Tohru, I read ALL of your information on your site several times. I did the same calculation and came to the same conclusion. This hacker motor has a lot in the torque department. With the 10 tooth and 7 cells, the head speed is a little slow. With a 15 tooth, this heli is a ROCKET! But, the speed controller does get too hot. I think I will try something in the 12-14 tooth area.

My question on the modes will be in a separite post.