Tuesday, May 17, 2011

Another Horizon Hobby quality defect destroys a classic

Radio control flight is unbearable fun peppered with heart ache.

Yesterday, my triple-redundant Optima Rx lost the ability to control what was quickly becoming my all time favorite machine, my gorgeous 50" Great Planes Yak-55m.  Puzzled, at how an Rx with an SPC connection, a dedicated BEC, a Pro ESC with switching BEC, all powered by a parallel double-battery system could lose power, I embarked on the necessary accident investigation that would make the NTSB proud.

Horizon Hobby's junk kills a gorgeous, high quality Great Planes ARF
Amazingly, the only single point of failure in the system failed, or maybe I should say, "predictably."  The setup?  Twin 4S batteries on a parallel cord Y-d into the ESC, from the ESC connector, a BEC and an SPC connector tee'd off to feed the Rx link and servo power, respectively, as well feeding the switching BEC on a 60A E-flight Pro ESC.  This all drove a Power 32 spinning a 3-blade MAS at (what I should have been) a rather conservative 45A max, measured, static draw solution.  This plane flew awesome, with phenomenal low speed manners and absolutely exhilarating high speed Doppler passes. Even if the copper-brick Power 32 was a little meaty for the plane.


During one of those high speed Doppler passes, perhaps 10 secs into an eye-poppingly stable, full power scream, the motor simply stopped.  No smoke, no squeal or shriek, no fanfare at all, just quiet with no change in flight path.  I thought I found a way to burnout the monstrous Power 32 with a puny 55 oz plane, so I turned to land; cake setup for a dead stick.  My gorgeous, perfectly behaved, always eager to please 55m disagreed, and proceeded forward, arrow-straight.  Dead.  In the air. 

I collected the carnage, and was still unclear as to the cause of this mishap until I began salvaging parts.

The culprit?

A cold-soldered E-flight EC3 joint that separated the ground wire from the 60A "Pro" ESC's factory connector under less than a 45A load.  The black wire that slipped out of the ESC side of this EC3 looked brand new, perfectly round and solid, and beautifully tinned, much like the gold bullet from which it separated:

Once again, Horizon Hobby's disregard for quality and rotten workmanship ate a fabulous model.  This is the lastest in fairly long line of E-Flight ESCs that have burned up on me in various ways, starting with my first experience with a Horizon model, the over-Amp'd and under-performing 25A ESC in their T-28 Trojan.  Horizon Hobby holds the world record for new an imaginative ways to find catastrophic, absolutely lethal failure modes.  Time after time, their stuff fails.  Buy nothing from HH, the  company absolutely, positively sucks.   Through blind luck, Horizon Hobby's gross negligence did not kill a human being yesterday.  Thank God for a fairly large world.

E-flight Pro ESCs moved to AVOID.