First taste of the sky

[Don Fry]

Yes, it’s a hold, records it as a hold if the block lasts for 40 odd consecutive frames.  Another telltale on Stectrum rx, when it’s had a hold, a red light flashes, 2 holds, double flash, et al. 
Toto, I think you are being logical. My first thoughts, ( but have no experience of single aerial rx), is I would work very carefully to make sure it’s in free space, no carbon or metal near. Another possible solution, bite bullet, fit a rx with a satalite. My default install of the satalite is down the fusalage 30 cm behind the wing, on a longer connection, then you get 2 aerials working without effort, but still take care of the rx positioning.

[leccyflyer]

Don - it's an AR620, which doesn;t have an external antenna at all. It's an excellent, full range, compact 6 channel receiver with fly-by telemetry.

[Ron Gray]

Toto your approach to this is spot on, strip out the radio gear (Rx) battery etc and reinstall, just to make sure everything is OK and double check all connections, especially those that you may have made (!). Sending your radio gear back to the supplier seems a bit drastic, if you doubt your Rx then fit another one and test that. You've got 2 TXs, ground test with each of these and see if there's a problem. Get your instructor to fly the model with each TX (no buddy). Loads of things that can be done before sending your gear back.

[toto]

Here is a couple of photos of the inside of the fuselage ........

 

It'll give you an idea of how things are laid out.....

 

 

and 

 

 

hope this helps

 

I'll be back with my TX fail safe settings shortly.

 

cheers

 

toto

[Don Fry]

Toto, my point is, it’s a good rx, but one aerial, poor reception, big problem. Rx with satalite. Three aerials, if one is working, the system still functions. Think 747, engine fails, hey oh. Think your trainer, engine fails, it’s coming down. 

[PDB]

AR410 located just behind the fuel tank in a Boomerang which has performed flawlessly, other club members have had no problems with the AR series of receivers either.

 

[leccyflyer]

Personally I prefer my AR620s to be sitting horizontally, but that location looks reasonably free of blanking obstructions. However, have you checked that the nearby control rod, with the slightly bent end isn't hitting the case at full deflection?

 

I think In an IC model I'd have that battery pack completely encased in foam and secured to the bottom of the fuselage, if it fits. You're transmitting vibration to it through that cable tie directly on the cells.

[toto]

Hi PDB,

 

I have 4 AR620's, one for each of my " trainers ".

 

Arising Star

Beaver

Tiger 60 

Domino

 

It seemed to be fine in the Beaver. Only just bound in the Domino and Tiger 60 so the jury is still out on them until Maidened.

 

I have say half a dozen eight channel spektrum telemetry receivers with multi antenna facilities bought for bigger more expensive models which going forward, once I get out of pure training mode, I intend to dabble more with telemetry, GPS, maybe fencing etc. I've bought into Spektrum in quite a big way so will absolutely be sticking with it, regardless of what my club flies.

 

I did a reasonable amount of reading up before I dived into Spektrum ..... just didn't " bind " the manufacturer with the club ..... and I wont either just because some eee telemetry as a black art. 

 

If I write off a TX or an RX ....... it has to be based on logical processes and science ....... not on a hunch or a dislike / unfamiliarity with the product.

 

As Ron says , there are many untried " logical " avenues to be explored before doing anything drastic.

 

Thanks for the feed back with your experience of the AR range.

 

Toto

[leccyflyer]

Toto - there's nowt wrong with the AR620, it's a fine full range receiver, with a lot to commend it.

 

Rather than saving your eight channel receivers for some unspecified more complex model in the future, it might be worth a go to put one in your trainer, with the additional antenna diversity available. I'm quite biased, but given the issues you have suffered with all those deadsticks, in your position I'd be ditching the IC trainer with the balky engine and going with the electric traner that you have and which I believe you'd said your instructor was happier with. Stick time is way more important to you at this early stage than wasting time in trying to sort out two stroke engines which don't want to behave.

[toto]

Hi Leccyflyer,

 

I'm listening.

 

I am going to disassemble ( is that the right word ) the whole lot and reassemble from scratch. I get the feeling that at present I could be adding worse to a system that is already flawed / bad.

 

I am not the fastest at these sort of tasks but I am determined that this has to happen in order to move forward on a solid footing. I will start the process tonight ( all domestics going well ). I am going to call time on any possibility of flying this weekend and give myself until the fol.owing weekend to have this model and its respective electrics and their set ups in a refreshed position starting from the cleanest datum point. 

 

I will attempt to set up the TX and RX including the buddying system from scratch as the current set up has been done on the hoof in a bit of a piece meal manner.

 

I'm not going to be rushed on this, it takes as long as it takes and if problems persist hopefully they will be a bit more transparent and identifiable.

 

Oh boy ..... here goes ..... again.

 

Toto

[leccyflyer]

Toto - that's fine and the forecast for the weekend isn;t the best, so if it isn;t flyable it's something to be done - but as you say, no need to be rushed..

 

However, if it is flyable this weekend, you'd benefit more from some flying with the club trainer and keeping up with your flying training. The equipment modifications can be done when it's dark outside -  you're in this marvellous country, but the nights are drawing in, the clocks will be going back in six-seven weeks and you only have the opportunity to fly at the weekends, so taking those opportunities are the single most important thing IMO

[toto]

No worries Leccyflyer.

 

The last word from my instructor yesterday was .... his TX and RX with the Arisng Star. That's not happening. As of 5onight, the Arieing Star will be stripped to its bare bones and given a full MOT. 

 

The underwire of the fuselage sustained some damage at the weekend .... most cosmetic ... the film ripped apart where it had previously been repaired. More importantly ( to me anyway ) is the fact that the firewall appears to be coming away from the side of the fuselage very slightly. That ... can never be good. 

 

I suspect, when I strip it back, there could be more issues as a result of a couple of hard knocks that it's taken so at least I will have peace of mind that a proper check ..... and any necessary robust repairs have been done before trying to move it forward. 

 

We could just throw it back up ..... get all the settings eventually working ...... only for these known issues to finally give in and take her back out of the sky again. ..... No ..... as my old mate Frank Sinatra would say ......... it's my way.

 

Let the club trainer take the thrashing this time.

 

Toto

[PDB]

Be worth checking the failsafe before dismantling it to see if that was a factor in the issues you've been experiencing. 👍

 

Power the TX and model up then turn the TX off and see what happens to the control surfaces and throttle. 

Edited September 12, 2023 by PDB

[toto]

Hi PDB,

 

I'll do that before I touch anything else and post up the results.

 

Thanks for remembering me.

 

Toto

[MattyB]

29 minutes ago, toto said:

No worries Leccyflyer.

 

The last word from my instructor yesterday was .... his TX and RX with the Arising Star. That's not happening.

 

Good for you. You have absolutely the right approach here - take a scientific approach, take out the RC gear that potentially has some question marks against it, and conduct some controlled tests on it to see if it is at fault or not. Just stripping it out and replacing with another TX and RX might fix it, or it may not; it certainly won't help you identify the true root cause or enable you to sign-off the RX and TX in question for future use. More science, less guesswork!

[MattyB]

28 minutes ago, PDB said:

Be worth checking the failsafe before dismantling it to see if that was a factor in the issues you've been experiencing. 👍

 

Power the TX and model up then turn the TX off and see what happens to the control surfaces and throttle. 

 

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

Edited September 12, 2023 by MattyB

[toto]

What position should the throttle stick be in when I do this ? Full down ?

 

Cheers

 

Toto

[toto]

Thanks Matty,

 

I could become very unpopular ( maybe not ) but I think a different, more logical and scientific approach is what is called for rather than just dismissing equipment without any truly firm logic behind it.

 

 

Its happening.

 

Toto

[MattyB]

6 minutes ago, toto said:

What position should the throttle stick be in when I do this ? Full down ?

 

Cheers

 

Toto

 

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).

Edited September 12, 2023 by MattyB

[GrumpyGnome]

So, move all the tx sticks from 'neutral', turn off the tx and see what happens to the control surfaces... 

[Ron Gray]

Take the prop off first!

[Graham Bowers]

5 hours ago, toto said:

Here is a couple of photos of the inside of the fuselage ........

 

It'll give you an idea of how things are laid out.....

 

and

 

hope this helps

 

I'll be back with my TX fail safe settings shortly.

 

cheers

 

toto

The layout looks reasonable to me, although I'm not a Spekky user so have no experience of that receiver. I have used Multiplex single antenna receivers, however they've been of the external variety, so easier to position the sensing portion away from stuff that may shield it.

 

I've followed this thread for some time and will comment on the traffic of the last few days:

 

Best practice is probably summarised in the BMFA handbook and in my opinion forms a good basis however the devil most certainly is in the detail that isn't included.  https://handbook.bmfa.uk/13-general-model-safety

 

In my experience this hobby has "Gotchas". The ones that come to mind that may come to bear here are:

 

In your layout photo things look pretty good. However when the wings are on, where does the aileron servo wire lie? I've experienced them (two in my case) laying such that they obstructed the Rx antennas and caused a range test issue. However they didn't always lie in the same place and cause the same problem, so it seemed intermittent. No loss of control was experienced and I'm now much more diligent about that aspect of cable management.

 

Range test. Related to the above, how many people turn and twist the model in 3D space in order to change the orientation of the Rx antennas to test a variety of signal paths? 

 

I've had a dodgy aileron servo extension exhibit an intermittent open circuit that caused the model to do weird things. The model was successfully landed and the fault found before any damage occurred. 2 channels for the ailerons by the way, so only one was affected.

 

Others have already covered the potential for power supply issues. I've found a switch issue when bench testing. Considerable voltage drop across the switch, so high resistance. I spend more on switches now, sometimes much more. Long story however telemetry voltage data was the key. When I removed the switch, and plugged the battery direct to the Rx, the problem went away.

 

I recently had an in flight receiver low voltage warning that I had help on in this forum. Bottom line is the battery I used was a little aged and past it's best. The learning was a) Low self discharge batteries (eneloop for example) have limitations on current delivery that may negatively impact the system. b) Conduct proper testing and ensure voltage sag is known and within acceptable limits. c) Routinely use telemetry to monitor battery voltage** and ensure the warning level is appropriate for the equipment. d) Keep tabs on NiMh battery ages, and retire appropriately.

 

** I do have a commissioning checklist and I've added routine review of telemetry Rx voltage plus signal quality to it.

 

The learning never seems to end and it seems that's a concept you've grasped. You'll have to decide for yourself what constitutes best practice for your models at the detail level and at this time. I see good examples of what I consider best practice, and examples of what I don't. Flight is forgiving, however the ground is not.

 

Good luck, this is a fantastic hobby. In my opinion.

 

 

Edited September 12, 2023 by Graham Bowers

[Philip Lewis 3]

19 minutes ago, Ron Gray said:

Take the prop off first!

No need to take the prop off as it's IC so engine won't be running and won't do anything no matter what the TX commands.

[leccyflyer]

56 minutes ago, Philip Lewis 3 said:

No need to take the prop off as it's IC so engine won't be running and won't do anything no matter what the TX commands.

 

I think that's a large part of Toto's problems 😉

[Ron Gray]

59 minutes ago, Philip Lewis 3 said:

No need to take the prop off as it's IC so engine won't be running and won't do anything no matter what the TX commands.

Oh yeah, I kinda got lost in the amount of discussions about this!