Another Suspect Futaba 6EXP 2.4

[Tom Doyle]

Some may recall my previous thread under 'All Things Flying' entitled 'Low Wing Balancing' posted 27/3/09 in which the full story eventually unravelled and was more to do with an unexplained model crash. It was no ordinary crash but the maiden flight of my friends first low wing model, a World Models Super Sport 40, piloted by me. The Futaba 6EXP 2.4 radio gear was suspect, it also being new and in use for the first time.>>

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In an attempt to determine the cause of the crash, a new Super Sport 40 was built and test flown yesterday. The new model was set up exactly as per the manufacturer's specification in terms of throws and C of G, as was the first model. It also had the same servos and same engine which survived the crash; the only change was the use of an FF9 35 meg Tx and Rx as opposed to 2.4 gear in the original. >>

Needless to say, it performed impeccably on its maiden flight, just how I expected it to behave, predictable and forgiving. In fact Geoff, the owner, who hadn't flown a low wing model before, confidently took off and landed the second flight totally unaided.> >

The first model went completely out of control on aileron, rolling inverted at the slightest stick input, almost as though it had positive expo. And therein was the second mystery. Before takeoff, there was minus 40% expo dialled into aileron and elevator. Upon inspection after the crash, the memory had cleared itself of all expo and was showing zero!> >

It is interesting to read about similar problems experienced by other Futaba 6EXP 2.4 users on this forum but at the same time, rather disheartening to suspect other issues exist with this equipment which manufacturer and distributor are reluctant to come clean about. Whenever a model crashes, finding the true cause is often an impossible task and invariably it goes down as ‘pilot error’. In this case, the circumstantial evidence is overwhelmingly against the radio equipment and I certainly feel exonerated of any blame on this occasion. Unfortunately, it does little for the confidence in what was once a leading manufacturer of quality radio gear.>>

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[Delta Whiskey]

Sorry to hear of your experience, I've been using my 6ex for a year now on an electric heli, with no radio problems at all.

 

I recently just brought an extra 617 FSST rx, and stuck it in a new Extra 300 I have, to use with the 6EX. I plan on maidening it tomorrow.

Edited By Delta Whiskey on 22/04/2009 21:22:26

[Tom Doyle]

Hi Delta Whiskey. Don't get me wrong, I'm not saying all 6EXs are suspect on the contrary, I think what happened in our case was rare incident, but happen it did. Good luck with your maiden, always a nervous time. Tom D.