MattyB

Following this conversation along, the more I read the less convinced I am that these "antenna-less" RXs are easier to install well. If you have two antennas sticking out you can bend them where they need to go and be certain they are oriented and put hem in the same plane as the TX aerial in the most common flight orientations. With the antenna-less RXs unless you take the board out of the case, how do you know which way the aerial is oriented, and therefore how to install optimally? Of course conventional twin antenna RXs are easier to damage, but from an RF perspective I just can't see an advantage. Maybe I am missing something and in most sport model installs it won't matter, but it does seems like a "convenience trumps performance" decision to me from Horizon Hobby.

Yes, the mean average power will undoubtedly be less than the endpoint limited “100%” throttle, but the median throttle rating in the average sport model probably is still full power. Perhaps that is a factor? I’m sorry, I am at the end of my personal knowledge here - for more on this you’d need to ask an esc designer or manufacturer. In posting I was not trying to categorically prove premature ESC death by part throttle running (I don’t think that is possible). I was merely pointing out the well understood factors that mean an esc is working harder and generating more heat at part throttle, leading to it getting less efficient as a result. As I don’t have any more insights to share that I could back up with data I’ll quietly leave at this point!

Hmmm, ok… I have gone back to the OP’s post and re-read it, and it’s true the thrust of that was more about any negative effects in the motor rather than the ESC. I do agree that, from the perspective of the motor, there should be no issue with running it with a reduced throttle endpoint to keep the peak wattage and current below the motors maximum limits. Apologies if I caused any confusion there. However, if you do that the ESC will generate more heat and be less efficient than if the motor were propped to allow its max power to be generated at the 100% throttle setting. Whether that could cause it to fail in the long run though is more complex - see my previous post on that point. Since no-one is going to have any conclusive data to say how likely that is, I just choose to avoid doing it in case it could cause a failure, no matter how unlikely that may be. YMMV.

Just go into the old model memory and note down the rates you had implemented, as your mentor will probably have fine tuned them after the maiden. TLAR is ok to a point, but if he set it up to his taste before, best to get as close as you can to that with the new model memory.

Short answer - I've no idea, and won't pretend to have! I posted above because gangster had indicated he was sceptical that the effect of running an ESC at part throttle could cause issues, and I had some reasonably well qualified sources that indicate the heating effect (and the resultant loss of efficiency) absolutely is real. I have no further personal knowledge beyond that, as my knowledge of how ESCs actually work is minimal. If there are ESCs that operate in a different way and don't have these issues I am not aware of them, but that doesn't mean they don't exist. However, in the last 10-15 years I if there had been a revolution in ESC technology it would have been well publicised in the modelling (and wider) press given it's applicability in all sorts of industrial and commercial applications. Has that happened? I can't personally remember it, but again, that doesn't mean it didn't occur.

There are two parts to this answer... Does running a brushless ESC for extended periods at part throttle cause the FETs to do more switching and generate more heat? The fact that ESCs run hotter and are less efficient at part throttle is well understood, and easily tested on the bench should you wish to do so (I did just that about 10 years ago when I was getting into larger, higher power electrics). If you don't believe me, fair enough, but the likes of Castle Creations (who've made an ESC or two - see below) and Steve Neu (of Neu Motors fame) have posted extensively about this over the years - additional links here. Is this likely to cause the ESC to fail prematurely? This is much harder to answer, as the way the ESC is run is only a single variable amongst a sea of others (peak and average sustained current, installation, ventilation, time between flights, etc.) that will affect it. I suspect the chances of ESC failure due to sustained mid throttle running are pretty minimal these days, but the probability is not zero. Because of that I will continue to optimise my powertrains without touching the throttle endpoint; it isn't hard to do, and there isn't any downside (it just requires some basic modelling in eCalc before you buy your components). FWIW, I suspect the most likely model type for this sort of failure is something like a Junior 60 - that will pootle around on low throttle ratings for long periods on sunny low wind days, entombed in a poorly ventilated glasshouse of a cockpit!

It's one of the great mysteries of aeromodelling... Why do those don't use or fully understand telemetry seek to "educate" those who do use it every single flight on why it's "worthless"? A short summary for those who aren't aware of how a modern voice enabled TX and RX that features RSSI telemetry works (e.g. Frsky, Jeti, Radiomaster, etc)... The RX is transmitting it's received signal strength (and often the power supply voltage too) back to the TX in real time from the moment it is switched on. The TX is (by default) monitoring that in real time, and providing audio warnings (again by default - no mandatory configuration required) based on multiple RSSI thresholds that are fully tuneable pre-flight should the pilot choose to do so. This means you will be alerted via a voice call out to any signal strength issue well before the model goes out of range, enabling it to be turned back and landed. In addition the pilot can configure TX telemetry info on the home screen by default if he wishes to, and have RSSI and RX pack voltage called out periodically on an ongoing basis or on demand at the flick of any switch. In combination this functionality is akin to flying around at full transmission power whilst simultaneously carrying out an automated real time range test, every second of every flight. Finally the TX voltage itself is also actively monitored and subject to voice callouts if it dips below pre-set thresholds, so again you'll be notified well before a transmission failure occurs that you should land and charge the transmitter. So yes, it really is far, far superior to an analogue signal strength meter on a TX from the 80s... 😉

The early module based FrSky systems were very quiet, so launching in range check mode was a relatively easy mistake to make - I didn’t donut myself, but my Dad managed it at least once, and was lucky to get away with it. Thankfully all the Frsky TXs are much more vocal in this respect, so it’s not something that would ever happen with one of those.

Quick clarifications on the above… 1) Yes, you’ve understood my original post correctly. The key thing is that (even if you don’t choose to reuse it in this model) you mustn’t put the original RX back in a draw until you’ve ruled out whether it has a potential fault. It’s easy to think “I’ll replace it temporarily with a new one and do that later”, but if that RX goes back in the draw it might not come out again for a year, maybe 2, possibly 5… will you remember to do the test then before reusing it? 2) Yes, the range testing is entirely independent and separable from your need to setup the model on a new memory on the shed. You can do a range test on the RX with any model memory and any collection if settings you like. The only thing to remember is to exhibit necessary care if it’s an electric model you are range testing (e.g. restrain model, or remove prop before you start). Of course that won’t be a factor for the testing of the original RX, which initially needs to be done entirely outside of the model.

Indeed. Fairly predictable, but it does put operators in an "interesting" position in relation to insurance; whilst the CAA have said they won't enforce the law, my understanding is that the change has been made and technically people are obligated to install a (currently nearly non-existent) RID modules. Could insurers use that as a get-out-paying-free card were you to have an accident that resulted in a claim? Xjet certainly thought so in his last video. It must worry commercial part 107 operators whose livelihoods are reliant on legal flying and being insured.

So in summary, these things are incredibly safe, there is zero evidence that risks are increasing, but the CAA will actively seek to regulate this space to a greater degree 'cos UK Gov and Amazon told us too...

Final addition @toto... If you have any questions or concerns about this RX, I suggest you search in this thread which seems to be the definitive one on RCGroups...

One key point... I strongly suggest you do not re-install the original RX until you have done extensive ground testing OUT of the model. It shouldn't take long... just plug in a known good servo and power supply, and to a through 360 degree range test as described in the RX instruction manual. I would also do it again with the RX on it's side a well given that was how it was installed. Assuming it passes the std range tests, check the telemetry report on the TX. If you get no holds and few fades at the normal range test range you can then be quite confident it was the RX install that was the issue, not the RX itself. If however you are seeing high volumes of fades and and/or some holds, you know that RX is suspect at this point and shouldn't be flown. PS - I recommend you watch this tech talk from Spektrum on these "antenna-less" RXs; they recommend a range test as per above, and nothing metallic any closer than 2-3 inches away (from ~3 mins in)... PPS - I didn't understand how these RXs could give good performance with a single antenna because that would seemingly work best only in one orientation plane. However, on investigation it appears these RXs use an PCB mounted antenna design from Texas Instruments (known as TI) that wiggles up and down to address this issue. Link to the TI paper Interesting, but on any model where the space is available I'd personally much prefer to install and orient the antennas myself.

They finally made the official announcement....

I always calibrate any new ESC with the TX as soon as I get it, that way when I plug it in it should "just work" when it's installed. Takes seconds, but saves on snafus like this. PS - Model inside, twin motors running with props on, held in just one hand one hand arm outstretched, pointing at a camera... What could possibly go wrong?!!

@Andy Symons - BMFA, have the CAA given any indication on how long it will take them to assimilate the submitted information and output the results? I am imagining that will be at least 3 months given the speed wheels tend to turn at the ministry.... 😉

Any more progress @Simon Chaddock? I haven't done much due to some health issues in the family, but should be able to order the powertrain and servos for these at the w/e.

On a firewall given it's position in the model adding extra epoxy won't make much difference, as it's in the right place, and if it is heavier there will normally be some nose weight you can remove or rejig of internals to balance it out. I completely agree on the 30 min epoxy though, I don't use 5 min for much at all these days.

Another option is the Optipower Ultraguard - the advantages with that are that you know your backup battery will always be charged, and telemetry or visual (via high intensity lighting) alerts can be added so you know if you have an issue with your main power supply. See my Sebart Miss Wind thread...

"...but as we can see we are glad to inform you that we are not offering some products coming from our UK warehouse." 🤦‍♂️😉😃

This has been discussed in multiple threads down the years, here's a couple. Personally I don't do it, but I admit the the odds are probably relatively low that you will have an ESC failure because of this unless you are operating the powertrain at the new limited "full throttle" for extended periods without modulation...

Post from that original thread showing what they posted on FB when questioned about the UK when they announced the new EU warehouse... The weird thing is that, given t is an open secret they are reopening in the UK and even shipping some stuff already, why do they not do an official announcement telling customers how it will work and when it is likely to open in full?

Was discussed here towards the end of last month. Why they do not announce their intentions, lord only knows... Who does their PR?!!

It doesn't matter, as the engine won't be running. The key is to see what the RX commands the surfaces to do when it loses signal. For an IC model, the throttle should go to idle, but not stop it completely. That should be easy to see from the position of the throttle linkage arm on the carb. This will be easiest to see if you have the throttle is partially open (say 50% or greater).

You should definitely do this test before taking anything to bits - it takes seconds to do, and could be very instructive.