Friday, April 1, 2011

Super Tigre ESCs - Moved to Avoid

I've moved Super Tigre ESCs to my AVOID list based on their poorly implemented arming safety sequence.

Most ESCs require moving the throttle to the IDLE position to arm the motor.  Super Tigre ESC have an additional safety feature that requires IDLE-MIL-IDLE before arming the motor.

The problem with the ST method is that, like all safety features applicable to flying, there are unintended consequences.  The unintended consequence here showed up in my Rx re-link tests between Spectrum (which far too commonly loses the link during in flight) and Hitec.  Once bound to the radio, the ST ESC must be armed using the sequence above.  After a lost link followed by link reestablishment, the ST ESC again demands the IDLE--MIL--IDLE sequence before rearming the motor, regardless of whether Rx power stays on from beginning to end.  This substantially delays the amount of glide time (or in the case of Spectrum Rxs, out of control time) required to get power reapplied to the motor.

There is no difference between requiring IDLE and requiring IDLE-MIL-IDLE, or requiring IDLE-DANCE A JIG-IDLE.   All of the above = IDLE.

Complicating the Super Tigre issue, you must listen for a beep after a second or two with the throttle in the Full Power position, before retarding the throttle again to Idle and again waiting for the three cell beeps.  So the ST ESC airstart BOLD FACE becomes:
  1. LINK - REESTABLISH
  2. THROTTLE - IDLE
  3. PAUSE 3 SECONDS
  4. THROTTLE - MIL
  5. PAUSE 3 SECONDS
  6. THROTTLE - IDLE
  7. PAUSE 3 SECONDS
  8. THROTTLE - AS REQUIRED
That is clearly unacceptable, and a great example of why "safety gurus" are usually so dangerous.