Tuesday, March 16, 2010

new crazy toy - Wheely king

-hpi wheely king
-7700kv brushless motor + Mamba max pro castle creations ESC.
-5000 mAh Lipo battery 20C (100 A max continuous)
- stock pinion is 21 teeth gear (not optimal) but the motor heats up considerably (so i ordered some 15-14 teeth pinion to see how it behaves)
it does wheelies all the time on grass and rocks and really goes fast! i don t think i dared to use maximum power yet.
the runtime varies a lot depending on the surface: 19 min on grass and 28 min or rocks only. with the lowest motor timing setting on the ESC (electonic variator, supposedly to decrease motor heating and increase run time)

onboard measured GPS speed (brushless):

it does not look very fast but it is. i could not even push the power to the maximum cause it was bouncing too much already at 1/2 throttle power. The max. speed measured on grass by onboard GPS is 35 km/h (not maximum speed on the throttle).

other setup:
i tried also the 27Turn high torque brushed motor given with the truck but it goes very slow and is quite noisy with my old 40 Amp electronic variator from 2002.

if you have the Mamba max pro esc: the stick programming in brushed mode does not work on the version below 1.25 firmware! it needs an update:
and i discovered it at my own expenses: i tried to program it with the stick and it stayed in brushless mode with a high torque brushed motor on... at the end of the programming, the ESC initialised and gave strong pulses to the motor that probably damaged the transmission's gear set!!! cause it broke dead when i replaced the brushless motor later on.

----------------old post:---------------------

here s a comment from a guy who baugh a similar setup than me.

"bought the 6900 system..............WOW. It goes 30+ (mph) with 6 cells at 22/93 and is totaly controlable. Not to many wheelies, as you guys mentioned, but lots of intense power and speed. I got 40+ minutes of runtime with a 3900 mAh battery pack and the motor didn't even brake a sweat. Great investment."

"The 7700Kv motor lets it all hang out for 6 cell or 2s lipo bashing and racing. On 6 cell NiMH the 7700Kv motor turns an easy 45mph in standard 10th scale buggies and trucks with standard gearing. With 2s lipo packs, you can expect 50mph for very large tracks or high speed runs."

i ll have a 5000mAh battery and a 7700 rpm/volt brushless motor (equivalent to 5 Turn loops, 100A current consumption max., +/- 390watt max. @ 7.4 volts (power's law not totally respected here (V . A = W).
it will get my hair disordered!
i can't wait to receive it this spring!