Wednesday, May 23, 2012

Soft Throttle

I've gone to a soft throttle approach with my powerful airplanes.

Some helicopter ESCs use a "soft start" to protect the gears from too much power too fast on initial start. I noticed a different, but similar issue on my hopped up 4, 5 and 6 cell brushless aircraft: ESC timing gets ahead of motor spool-up time due to the high mass and subsequent momentum of the larger bells, props, and spinner assemblies, often causing the motor to choke back to a hard idle reset.

I discovered the simple trick of setting a servo speed delay between 0.5 and 1.5 seconds on the high side of the throttle curve cured every one of these ills. There is actually no slowing of throttle response, since the physical momentum of the motor prevents it from spinning up any faster, regardless.  This idea simply matches the ESC timing to reality for reliable throttle operation.
 
I'm not sure why I've never seen this discussed before, I suppose most people don't like to push performance like I tend to enjoy.   I find it invaluable.  No more ESC slipping and choking when I need power the most!