Lee Burke

Glad they are going to replace the Rx.  Good service.  But in a way, its almost more worrying that they are so ready to replace it like that without even seeing it.  Do they know something we don't?  Makes one a little nervous.    

Timbo-ESC way, more like

Shaun, you have to try to do it just as it was in field, preferably in that field as well.  You want to try to find a foam box that has about the same size as your cockpit and put the electronics in there as they were in the Fury.  Then you need to sit it on the wings and the tailplane and connect everything up again.  Its the only way to repeat the event.  Maybe you could jam toothpicks into whats left of the fuselage and stick it back together like that just for the test.  In that way you are getting as close as you can.  Run the motor at the same speed as you did before the crash.  The thing has to fail again.  It just has to.  Hopefully. 

Back in 1909 when De Havilland was building his first aircraft he used the "intuitive" push the right hand bar to go left method of rigging, later he discovered that almost everyone else had it the other way round and he was obliged to change his system.  It took him a good while to get used to it too.

 Unless they are unusually thorough, the people you return the Rx to will run a simple test on it and probably find it works okay, just as you did.  That leaves you in the dark.  In your place I would attempt to recreate the same conditions that ocurred during the flight to get to the bottom of this.  The setup needs to be enclosed in the same (or similar ) way it was during flight.  Then you need to be in an open area where you get some distance between you and the setup and run it under as close to the same power conditions as just prior to the crash.  If you can repeat the event in this way you can probably isolate the culprit.  I'd say it was worth the effort.  The set-up as shown in your photo looks too open to replicate the real conditions.  Best of luck, anyway, Shaun.

Shaun I know yours is not Futaba but what's good for the Goose might well be good for the Gander.  You have probably read this stuff from Futaba, but just maybe you haven't.  As you say you can't always get thr Rx very far from the other stuff, but, just maybe it was getting too hot.  Don't wrap your FASST receiver in foam. Protecting your receiver from vibration by wrapping it in foam used to be a "must". Not so with 2.4GHz FASST receivers. Unlike 72MHz equipment, they're not as vulnerable to vibration. Using less foam lets them operate cooler - which is a plus for all electronics. Tip: To keep the receiver cooler use small foam blocks (like standoffs) so that there is an air channel around the receiver. 2. Shade your model from sunlight when not flying. Clear canopies expose the radio compartment to direct sunlight which results in additional heat in the model interior. This causes no problems during flight, but makes shading your model on the ground very important. Cover the canopy with a white towel; or better yet, park your airplanes in the shade. This will help keep the electronic components cool. Tip: It is important to note that lighter covering colors will absorb less heat whereas darker colors will absorb more heat. 3. Mount your FASST receiver away from heat sources. We had to avoid mounting 72MHz receivers near anything that might produce RF noise. That's not as much of a concern with 2.4GHz FASST receivers - you should instead make sure that you're mounting the unit in the coolest part of the radio compartment. Stay away from the muffler exhaust, battery packs, regulators or any other heat source. We also recommend that you use the receiver's long, narrow side as its base (rather than mounting it with the bottom flat against the radio compartment floor). Secure the receiver using a Velcro® strap or gel tape. --------------  If it wasn't over-heating,  then maybe the power was dropping out.  The fact that you were not demanding much from the battery today might have meant that the UBEC was having to dissipate more heat than yesterday in its attempt to step down the volts for the Rx.  I think I read something like that about BECs somewhere.  Hopefully the experts will be able to exclude that idea in short order.

What a swine!  Bad luck, Shuan.  Where is the Rx located?  I see that Futaba recommend housing it as far as possible from any other elements that might warm it up .  They also suggest fixing it on its narrow edge to promote cooling.  When you ran your tests did you put the cockpit back on and try to recreate the actual temperature of the flight?  Do you think it could have been the Rx heating up?

Thanks for providing the link to the Multiplex Peak filter, Capt.  Kreman.  It seems designed to preventing damage from spikes as well as power drops.  Pity they don't give any specifications, but it looks like just the sort of accessory that Marck Krief  recommends.  I also agree with most of what Always Broke writes, and he says much the same thing as Timbo; and obviously we all hope we are installing adequate equipment and should blame nobody for ourselves for our own cock-ups.  The problem is knowing just what one can rely on, and taking nothing for granted is a good policy in any pursuit, I guess.  Your second point about earlier electronic equipment not suffering power fluctuation problems is interesting, but so far nobody seems to have had any problems attributable to power fluctuations with the new stuff either, well, not that I have read of anyway.  Perhaps it is just hard to nail a problem down to that particular weakness.  There are so many imponderables, not least the magnetism of trees.  I understand that over the years as electronic equipment has become more sophisticated it has also become more susceptible to fluctuations in current., and it is possible that earlier equipment, while less complex, was also more resilient to this, although no doubt it had other irritating flaws.  But I have absolutely no expertise in this area and just offer my two cent's worth, or maybe not even that. 

I can't find the Multiplex capacitor Capt Kreman mentions, it would be interesting to know its specs, one would think Multiplex, at least, knew what they were doing

I am not sure what the answer to your first question is, Captain, since our good guru Timbo has never experienced the Rx blackouts described in the article and his information on 2.4Ghz receivers and the use of buffer capacitors is at odds with that of the author of the article, it looks like the jury is out on it.  I guess its up to you if you think the £5 is worth spending,  You would need to know if it at least complied with the parameters set out by Marck Krief in my first post.  If I had a big expensive model and were flying it anywhere loss of control could injure spectators I think I would adopt the all precautions in Marck Kieif's article.  They surely can't hurt.  On the other hand just buzzing around in a light powered glider, say, I'd probably not bother too much.  But that's just me

Great, thanks for reposting that info, Timbo.   I'd never seen that before, and even if I had it never hurts to drum things in,

Fairy Snuff   Did I get it right this time?   No, Marck Krief wasn't talking exclusively about electric flight, he simply meant, as you say, use the right battery for the job of powering the Rx, and that this is not necessarily the one proposed by the LHS. There was, inevitably, something "lost in translation" and it was a fairly long article so of course I didn't put everything in my post.  For instance, his figures show that increasing the wires to 0.5mm can result in a saving of up as much as to 0.4V on 5 servos which is a surprise to me at least.   But maybe only worth fiddling around changing wires on a "full house" set up.  The most contentious feature of his article remains the statement that 2.4Ghz receivers are the most "delicate".  Perhaps this is a question of just what is being assesed.  He lists types of recievers among which are these  : PPM    requires 3.6 to 9V.  Consumes < 10 mA.  Has excellent  tolerance of electrical disturbence (spikes and power-outs) and recovers immeadiatly from a tension dip. PCM                  3.6 to 9V                      <30 mA      Good tolerence           Recovers quickly PPM Synt          4 to 8V                         <30 mA      Average tolerence      Recovers  quickly to moderately quickly 2.4Ghz               4 to 9V                         <70 mA      Weak tolerence          Recovers slowly Now, as I said, I don't know on what these conclusions are based,  perhaps his own research.  I know these are not academic papers but it would be nice to have that kind of information as well. I didn't mention it, but his oscillographs show that the addition of a condenser buffer smooths the voltage drop on servo demand  and, for example, in the case of the 6V 2100 mA NiMH pack reduces the drop from 3.48V to 3.96V. Personaly I can't see myself bothering with most of that stuff (apart from the batt pack) just yet   But I did find it interesting. Thanks for your comments, Timbo.                                   

It is interesting and reassuring to hear your take on this, Timbo.  I do not pretend to be in a position to make any judgement here.  I thought the article of sufficient interest to mention.  It is, in fact a two-page spread complete with oscillograph readings and tables.  Marck Krief writes for a number of magazines which have an interest in electronics in Europe and reviews for example for Topmodel. I have no idea of his credentials but assume that the editors of these publications considered them authorative.  He might, for all I know, be the Marck Krief who is the head of engineering and electronics at the France 2 TV channel,. The "packs designed for propulsion " is my fault, it is a more-or -less direct translation from the French text: "Elements destines a priori aux propulsions electriques"  and by that I understand the author means those battery packs which have the characteristics required to supply power to an electric power train - as against one suitable as a purely Rx pack. The table he gives showing relative parameters of various types of receiver lists the range of acceptable voltage their current consumption, their tolerence to electrical disturbance and their recovery time.  Copywrite considerations prevent me from reproducing it, of course, and again there is no mention of sources for the material -a woefully common habit, so one cannot judge, if one were able to, the value of the figures.  Clearly bad news always makes interesting reading even in hobby magazines and its possible the article is simply a "filler", but Mr Krief seems to be considered an authority.and his opinions of some value. But again, I just put it there.  Don't shoot the messenger.  Personally it is the first I have heard of this particular problem, should it be one.  But then I am new to this and like a lot of us - still learning. 

Well, my science is pretty sloppy, Mike - just keep hitting trees is all 

Newton's Fourth law of Motion:  Every tree, bush and fence has the inverse square power of attraction to that of clear air.

An interesting article written by Marck Krief in a French magazine, RC Pilot.   According to his tests on flight packs that were charged to 50% of their nominal capicity, a 4,8V 1050 mA NiMH flight pack can drop to 3,46V under demand from 3 servos loaded at 1kg each.  This will cause the Rx to switch off and reboot resulting in a nasty, and probably disastrous, moment for the pilot.  He found that 6V pack dropped to 3.48V.  He lists various types of receivers and gives their susceptibility to brown-outs - the most modern variety - 2.4Ghz being the most delicate and slowest to recover.  He mentions also, of course, the threat of overheated ESC's switching themselves off.  Then he gives some solutions. 1) Use 0.5mm wire (instead of the ususal 0.3mm) to connect the battery to the Rx and keep the wire as short as possible. 2)Use 5 element packs if the servo's can take them. 3)Use only packs designed for propulsion. 4)add a supplementary capacitor external to the Rx (which has its own inbuilt). This supplementary capacitor is aimed at providing enough power to keep the Rx alive when the battery-pack voltage dips.  He suggests using a condenser with a service tension of 10V (or 6.3V), an internal resistence of <0.4 ohms and a capacity between 2000 and 6800 microfarads.  The condenser is connected to the Rx via servo plug to a free channel.  This may be old hat to many, and the author remarks that such condensers are available on the modelist market ready wired. 

Wow, difficult to say who is more reckless, the pilot or the crowd watching.  Great dodge, though, certainly saved the plane

As well as . . .

No, Timbo, my Fairy Snow is an admixture of Old Timer's and Missed Conceptions   But "There ya go!" sound's good to me, LOL You're bound to net some, Jetsome, That mass balance on the C-172 rudder is pretty well hidden

Eric, its well worth downloading the Adobe Shockwave player sometime - when you have time - as it it is often used for these types of video clips which can be quite useful in visualising something.  One never seems to have the time or patience when visiting a site for a quick look-see to fiddle around with these things, but its a good download to fill in an in an idle moment (as if such things existed) so as to have it on board next time.  Anyway, Fairy Snow, as Timbo says. 

Better luck with the new one, Ian   I understand that even if the motor is not being run the ESC is still taking current from the battery and would even eventually drain it, even if the ESC switch is set to Off.  So that is a point to watch. 

This Link shows a photo of mass balance applied to the rudder of a C-172.

GiantCod in its (his?) guarantee information warns: Never run your setup with no load - this is an instant guarantee disqualification. Quite why this is, I myself don't know, but Giantcod must believe it has a very negative effect. 

On consideration, I realise it is probably not necessary to change the Thunderbird settings to leave mail on the server; it would be enough to check the ISP message service and ensure their antispam is not blocking the notifications.

Timbo, if the notifications come through okay on a differant email address that would clearly suggest your client settings are fine, If the working email is a webmail address such as Gmail and the blocked address is your ISP email it is possible that your ISP has changed and intensified their antispam and is now blocking the notifications automaticaly.  May be worth changing the Thunderbird settings so as to leave mail on the server and  then check on the ISP to see if the notifications are there. Just a thought.