[NSRCA-discussion] Electric Motor Problem

[Ron Van Putte]

I have converted a World Models Spot-On 120 for electric-power.  The  
motor is a Dualsky 6350 - 12T (2000 watt), swinging an APC 18x12 E  
prop.  The speed control is a Jeti Opto 90 Advance.  Using the Jeti  
programming card, I set the timing for OUTRUNNER, the brake for OFF,  
the cutoff voltage to HIGH, the cutoff type to SLOW DOWN and the  
throttle curve to LINEAR.  I am using a Futaba 9Z transmitter, with  
the throttle throw initially set from -100% to +100% as indicated in  
the Jeti instructions.

When the throttle is advanced, RPM builds up normally, but at about  
60% of throttle stick position, the motor 'chatters' and I have to  
shut it down.  If I don't do anything other than reduce the high  
throttle in ATR from +100% to +80%, the motor comes smoothly up to  
maximum RPM.

What's going on?

Ron VP