Near fly away!!!

[Olly P]

Classic lose of signal, and thankfully the Fail-Safe had been programmed correctly.

I had this discussion at a former club once, with a 3D flier about why he should set the fail safe, appart from the legal need, and I pointed out that the sudden change in behaviour would tell him that it had engaged!

In response to the OP I would be sending both Tx and Rx for testing to HH....

[Mondeoman]

Posted by Tim Mackey on 03/03/2013 20:53:58:

Posted by MikeS on 03/03/2013 17:36:11:

Been using my DX8 (V2.06) since last october. So far only moved two planes over my Pawnee 40 (AR7000 DSM2) and my Pulse 25xt (AR8000 DSMX).

Up until yesterday I have had no issues as far as I am aware. Flying the Pawnee yesterday I started to get engine trouble where the ASP70 FS would cut to idle and back power, I landed and checked over the engine etc and all seemed good.

Next flight it happened again so I thought ok get it back down as this will need a more detailed search. I flew the Pawnee out for the approach and again the engine cut but this time I had no control.

I had that sickening feeling that I was watching my plane fly away. It slowly started to lose height as it got further away. I was thinking will it hit the line of trees or come down in them, then the engine went to power again and the controls responded. I banked it round and made in for the approach.

It dawned on me that I was not having an engine fault but the failsafe was kicking in.

First thing I did was check the rx and the light was solid on both the rx and satellite. I checked for any loose connections between the lipo, lipo reg and rx and all look good nothing was loose.

Since getting home I have removed the whole system from the plane, the reg is putting out 5.9v and lipo had good charge.

So I am lost at the moment, this setup has been in the Pawnee for the last two years and worked without fault. The only new component is the DX8 and as it seems the failsafe kicked in the rx was doing its job which points to the DX8.

Edited By MikeS on 03/03/2013 17:43:50

Once again I am reminding people that any suggestion of failsafe operating, and relationship with a power drop/outage ( brown out ) are NOT CONNECTED.

To me, this a classic lost signal issue, and the reasons for that, as with ANY radio system could be numerous, but dont include a power failure issue.

Suggesting that a move to a rival brand is the answer is simply muck raking - naughty naughty Stephen.

If your only criteria of a reliable sytem is your own experience of the one you use, then I could equally suggest to Futaba/hitec.mpx etc etc users......

"Change to spektrum, no more problems for me"

Perhaps I am just lucky, but after a DX7, a DX6i, and now a DX8 in constant use over a period of 7+ years, and literally thousands of trouble free flights, in over 40 different models of all types, jets, gliders, electric gliders, trainers, sport, indoor, and large scale etc - all I can ever really fault diagnose after my few incidents is the pilot/builder.

Well said Tim, this constant sniping by folk against other TX makes should stop.

[Steve Hargreaves - Moderator]

I'm not a Spekky user so my knowledge of the system is very limited but does the Spekky go into "failsafe" when the battery voltage drops....?

My old Futaba 35MHz PCM Rxs used to cut the throttle to idle as a warning than the battery was getting low.....saved me a model when a brand new Rx battery was unable to hold a charge & ran low during its first flight....

Just a thought....

[Tim Mackey]

No, it only goes to failsafe setting when the signal drops out - it requires a proper power supply level

in order to move the controls to those failsafe positions!

[Steve Hargreaves - Moderator]

Ah OK.....I'll get me coat.....

The Fuby PCM went into failsafe at somewhere under 4 volts as I recall.....

[Tim Mackey]

Sounds a potentially better idea TBH Steve ( the failsafe I mean ....not the coat LOL )

Having said that, I well remeber losing a model to PCM failsafe kicking in - and hated it ever after.

I much prefer to see some glitching in the model due to interference or power drop etc, rather than it just shutting down and leaving the pilot helpless to just watch it plow in.

In a similar way, the old brown out "problem" is a bit over-rated - with the very short re-connect system now evident ( certainly on the spekky gear ) one would probably not even know that one had suffered from it, if it were not for the flashing LED upon landing.

[Myron Beaumont]

I don't know about anybody else but you all must agree (not knowing anything about Spekky stuff ) That anyone just starting out in modelling would be confused by their names and numbers mentioned in all the threads (me included) if they are connected to the internet of course -otherwise not. The amount of info about sorting all the problems is obviously very good ,but why oh why do they keep rearing their ugly head . Don't you think that the manufacturer would have something to say in this very competitive market to enhance their reputation not let the competition rule the waves (excuse the pun)

You all know what gear I use -Never a problem for as long as Timbo has had satistaction out of his gear .

[Nev Haycox]

I spoke to Tom at Horizon Hobby today and will send in my DX8 and receiver for examination tomorrow.

I will let you know the outcome.

Nev.

[MikeS]

Nev. I think that is the best course of action to be sure.

Later on i will have a look at the mini plug but I will be sending both the rx and tx back and will go back to my DX7 for a while.

I think once I get the DX8 back it will need to earn my trust again so will fly my pulse with it unitl proven.

Mike

[Nev Haycox]

Hi Mike, Yes I agree, I will also have to regain confidence in my DX8, I guess my trainer will have to come back into play. I mailed rx and tx off today so will keep you posted.

Nev

Edited By Racing Snake on 05/03/2013 21:10:09

[SkippyUK]

Although I don't claim that this is a problem in this case, I would like to draw peoples attension to the new technology being introduced to mobile internet and telecoms.

I fly small foamies on the beach at Instow and often used the large flat sand in front of the army camp as it's quiet and only used by the Marines and Topgear...

I suffered several lock-outs but fortunately recovered all but one which went down in the sea.

On investigating this I found that there is now a new Microwave Link between the telephone mast by the cricket pitch (1000+ yards away from where I fly) and Lundy island (some 9 miles away a cross the sea) and if I fly near/through the beam then I lose control until the model emerges from the other side and reconnects.

None of my RX's suffered damage and I now fly further along the beach with no problems.

After posting this on another forum i was informed that there is now a new grid of microwave antenas springing up between lots of these new mobile masts in preparatoin for 4G and it's more prevailent in the country where a microwave link is cheaper than laying a fibre cable.

Morel of story - keep an eye on local telephone masts and if there's suddenly one of those dustbin type microwave links pointing towards your patch, beware.

[Olly P]

Yep - this is called 'swamping' and essentially the Rx has to discount so much of the stuff it is picking up (even though on different frequencies) it doesn't have enough processing power left to track the signal it is supposed to respond to. It is essentially an accidental form of radio jamming, as used to prevent communications in a military environment.

Keep an eye on planning applications as these have to be applied for and if one is going to affect you then react early!

[MikeS]

Made a call to HH today and spoke to Glen at their technical department.

After a brief chat about what had happened he advised me to send in the DX8 and the rx to be tested. I also received an email from glen which I had asked for so I could include a copy of the discussion when I send in the DX8.

Now glen suggested that 30 paces suggests the DX8 was working fine when range testing, he suggested that the AR7000 was not the best RX for the Pawnee as it is a large plane fair enough and the receiver positioning may not be idea. However after some 200+ fault free flights with the DX7 maybe I was just lucky?.

I always thought the AR7000 was fine for the Pawnee and it is suggested in the Build manual?

Copy of email:

 

"Hi Mike,

The best thing I can suggest is to return the transmitter and receiver either to your model shop or you can send them into us directly with a covering letter and copy of proof of purchase so we can test them for you.

It is strange the model passed range check which possibly suggests receiver positioning may not be ideal. An AR7000 is not really the most suitable receiver for such a large model, ideally you would need a receiver with more satellites which can be positioned around the model for optimum signal reception.

If you send the radio in to us we can at least ensure it is functioning correctly.

Regards

 

Edited By MikeS on 06/03/2013 18:32:17

Edited By MikeS on 06/03/2013 18:33:41

[MikeS]

Posted the DX8 & RX today. So we will so what happens.

Mike

[andy watson]

At the risk of kicking off a S/F argument...........why does a big plane need satellites any more than a small one? My receivers have no satellites and I have never had this issue.

[Olly P]

Andy - I happen to agree - to a point!

If the aircraft is made of any none-shielding material, then any Rx should be OK - the problem would be any shield effects, possibly from big lumps of metal/electronics. but 2 well located ariels should be sufficient to overcome this. For aircraft made from shielding material (such as CF) then I could see the argument for more satellites, to ensure at least one had good signal lock at all times.

[andy watson]

I am assuming that in this case there is no significant CF content to the model- this would certainly be the case in most large models compared to small ones. I cannot understand why HH would suggest more satellites for a bigger model- assuming all other things are constant.

[Braddock, VC]

Andy, there used to be an old student's rag joke about "Umbulla" I think that's what it is.

[MikeS]

Well the plane in question is the Hanger 9 Piper Pawnee 40. No carbon to be found in the model.

When I sent it up I placed the regulator and Lipo in various locations each time doing a range check with the Dx7. Each location gave the same results and had no problems with it until now with the DX8.

I thought the AR7000/AR7010 would be fine in the Pawnee as I have always thought of the rx was for larger models. To use more satellites means buying an rx that has the option and I believe the next one is the AR9000 and you need to buy the second satellite.

Edited By MikeS on 07/03/2013 16:08:21

[Nev Haycox]

UPDATE AS PROMISED

I sent my DX8 and AR6200 rx in for examination on Tuesday and received them back 10.30 am Friday.

A fault was found with the RF board in the DX8 so they replaced it and recalibrated the Gimbals. They also installed the latest firmware in the rx, all FOC.

You cannot get better customer service than that, well done and thankyou to all at Horizon Hobby.

Nev.

[Delta Whiskey]

You can get better service than that by not having this fault in the first place! Any QA ?

No manufactuers war starting is intended here at all, but I will certainly not be buying one of these.
Will they replaced any smashed or lost models too !

 I would have expected and demanded it was FOC too.

Edited By Delta Whiskey on 08/03/2013 11:54:22

[MikeS]

Nev. Glad to hear you got it back fixed. As per my other post at least you know it was an issue.

One thing that worries me if that I keep hearing of DX8's having the RF boards replaced. My next question on average how long do these boards last and is it a one time fix due to a batch of bad of boards.

Mike

[Nev Haycox]

I have just spoken to Tom at Horizon Hobby and as far as he's aware there is no big issues with the RF boards on DX8's.

I Know your saying "well they will say that" but I can only repeat what I'm told. I will start a new thread, so lets see.

Nev.

[MikeS]

Posted by Delta Whiskey on 08/03/2013 11:53:42:

You can get better service than that by not having this fault in the first place! Any QA ?

No manufactuers war starting is intended here at all, but I will certainly not be buying one of these.
Will they replaced any smashed or lost models too !

I would have expected and demanded it was FOC too.

Edited By Delta Whiskey on 08/03/2013 11:54:22

To be honest Doug I was very reluctant at first to buy the DX8. As you know I was thinking about the Arora 9 but after chatting with others at the club they all reported no issues with the DX8. I did a bit of research on the net in the months before buying it and felt from the posts and software updates all the bugs had been ironed out.

Now before I get jumped I not saying my DX8 is the issue here or am I saying anything is wrong with the DX8 overall, so until I have heard back from HH we will have to wait.

I seem to remember one chap getting a model replaced after a crash but unless HH find a problem that comes under warranty I would imagine that they would not replace any crashed model as too many variables come in to play that could cause a crash that some pilots blame their radios when it was pilot error.

Mike 

Edited By MikeS on 08/03/2013 13:24:38

[andy watson]

Am I right in thinking no really understands why satelite receivers are needed, or what the relationship is to the size of the plane?

The only idea I could come up with might be big planes can be flown further away from the tx than a small one, but beyond that tenuous logic I couldn't think of a single reason.