At_Your_Six

Hi all,

Has anyone had a loss of control problem using a Spektrum DX 7 and a AR7000 Reciever?

I have had two loss of control incidents resulting in the total loss of control and two destroyed aircraft. Both aircraft used the same AR7000 receiver. The first aircraft was using all components that come with the DX 7 radio, 4 Spektrum digtal servos, 4.8 volt receiver battery pack and AR7000 receiver and ON/OFF switch. That plane crashed on it’s 4th flight, aircraft rolled right with out command and did not responed to opposite control input. Plane was completely destroyed.

Second aircraft used all new equipment, 4 JR 821 digital servos, 6 volt 1500mah receiver battery pack but used the same AR7000 receiver from the first plane after long check out process for any possible receiver problems. Second plane had a loss of control right after takeoff with the same roll to the right without command given and would not respond to new stick inputs.

I called Spektrum product support and was told about a low voltage reset that can happen if the receiver sees a momentary voltage of 3.2 volts. Product support told me that the receiver would go into a re-boot if this voltage is seen by the receiver, the receiver would not work until it completed the re-boot process, that takes seconds to complete. I asked him why this information was not in the manual, he did not give me a answer. Does anyone know about this issue? I am sending back this receiver to Spektrum for evaluation.

I would like to have someone from Spektrum contact me about this problem. I am hearing more and more of these stories on other websites and I am unwilling to fly my other aircraft with th AR7000 receiver until I know what is going on. I have lost two new 40 size electric aircraft to this problem at a large expense to my pocket book. I think some compensation is in order for "US" that have lost our equipment through no fault of our own.

Thanks


Update: Today April 17, 2007

I just got off the phone with Todd at Horizon Hobby, He referred me to page 102 in the DX 7 maual which states “Do not fly below 9.0v on the transmitter or below 4.7 on the receiver. To do so can crash your aircraft�

Now I ask you, Don’t you think this statement should be placed a little more in the front of the operators manual? Todd told me that a 6 volt Rx battery would be a better choice than a 4.8 volt pack. Well I have one question then, why does spektrum ship a 4.8 volt battery pack with every radio if 6.0 volts is a safer option to avoid an in-flight receiver re-boot? I told him I was a big supporter of spektrum products but I now don’t feel I have been given the information in a manner that allowed me to fly my aircraft in the safest possible way. All also asked if they would in any way compensate me for the loss of both planes and Todd said no, we do not cover collateral damage from the use of our products.

I am very disappointed by the way specktrum has handle the information and customer service issues here.


Six

****Update: April 18,2007****

This looks like a fix for low voltage re-boot issue

http://www.horizonhobby.com/Products...ProdID=SPM1600

It's called a SpeKtrum Voltage Protector $6.00

I order 3 today

Why did not Spekturm support tell me about this????

Why not give these free to people that have lost aircraft to this problem as a good will jest rue???

*****Update April 19, 2007****

I recieved the Voltage Protectors today, will install them this weekend and fly with them next week. I have installed a new 6 volt 2700mAh Rx pack into my last 40 size plane and will cycle the pack a few times and load test before use. I will update you after flight test.

Six


*****Update April 24,2997****

I flew today with the voltage protector install. Four flights no problems. This plane has been rock solid from the first flight so adding the cap did not screw up anything. Still waiting to hear from Horizon about the reciever I sent back for eval. Will update when I hear from them.

Six

*****Update May 4, 2007*****


I want to thank the poster for this information:

" portablevcb
Neophyte hacker

portablevcb's Avatar

Join Date: Sep 2003
Location: Albuquerque, NM USA
Posts: 5,853

You should feel a bit vindicated. The JR sponsored noon demo at SEFF included the crash of their demo plane due to the rcvr low voltage problem (new JR tansmiatter with Spektrum built in). They announced over the PA that they had duplicated the problem on the bench later with the same system and another one to verify that it was due to high current draw from the digital servos pulling the voltage too low for the receiver.

Now, the question is, what will JR do about it?

charlie"


Well I found the video of the plane crashing into the ground!!!! The crash happens 2/3 into the video just after the guy on the PA system gets done saying how great the JR/Spektrum link system is,

http://www.rcgroups.com/forums/show...hmentid=1293966
(You will need to type this into your web browser, the link will not work from here)

Here is Horizon Hobby's response to this Incident:

http://www.horizonhobby.com/Articles...ArticleID=1674



It just shows all of us that we need to pay attention to how much power these servos need and what can happen if we don't.

Six


******Update May 5, 2007*****

Hi All,

I finally received information on my AR7000 sent back for evaluation at Horizon Hobby. The technician at Horizon after performing a range check and burn in on the bench for ½ hour found “no trouble found, receiver works normally�. Now to be fair, Horizon did decide to replace the receiver at no cost, which I do appreciate. Now I wish they did find something wrong because now I don’t know if I am any better off with a new one.

I guess I will switch back to non-digital servos!

Six

balsafire

My Feedback: (4)

Hey Six
This really has me worried. I just got back into this hobby after having ALL of my planes and equipment stolen. I have the DX-7 with a total of 2 flights on the entire system. Here's my real worry, if I am using the four spektrum servo's along with a standard JR 543 on throttle and a Hi-Tek 5645 mg on rudder and the spektrum supplied 1100 mah 4.8 battery fully charged how long will it take before my voltage drops below 4.7. Where have you seen the other reports of trouble? I really want to know what to look for. The plane this equipment is in now is ready for maiden with about $1,000 invested. I really want to avoid another major setback.
Thanks in advance,
Rod

rmh

balsa fire -- you do not have near enough battery capacity ( my opinion) for your setup -- further - a 6v setup is better for servo response.
There is simply NO way to predict what the flying time span is for your particular battery /servo setup -
too many variables.
There are a number of guys in your area flying the Spektrum systems- check around and get some informed info on battery drain and servo/ flying combos
PS the stock 4 servos and the stock battery are fine for a simple sport model but as soon as you increase numbers and types of servos and IF you are setting up what is referred to as 3D throws - you need far more capacity-

balsafire

My Feedback: (4)

Hey Dick
Thanks for the reply. I am feeling really lucky right now. The plane my system was in was a Pitts and had the stock Spektrum servos(4)plus 4 more, total of eight. It was my "come back" plane and first bipe that I built. I only flew it twice and gutted it out and sold it. I must admit the electronics aspect of this hobby is the part in which I am most lacking in knowledge. Electricity in general has always baffled me. At the risk of sounding dumb, do they make a 6 volt pack that simply plugs in like the 4.8 or do you have to make your own? The plane I am setting up now is a World Models Extra 1.60 and while I don't really fly 3-d, I do set my models up with quite a bit of control surface deflection with a lot of expo. I am planning on staying pretty much in this size range for a while and the whole set up is new territory for me having flown mostly .60 size sport models. Do you think this is what caused Six's problem. Oh, and thanks Six for the post. Sounds like you may have saved my bacon. Realy sorry to hear about your planes.

Rod

alan0899

G'day Mate,
It does not matter what radio you are using, if the battery does not have enough capacity, or has not had a proper, balance charge & been cycled to get it up to full capacity, when it was new, the plane it is in will drain the battery & crash.
It's just that the DX7 is new, & some people think they are foolproof, well they are not, the RX still needs power, & so does the servos. Without that power, they will stop working.
End of story.
Check out this page for balance charging procedures.
http://members.aol.com/davthacker/balancecharging.htm

rmh

a simple setup-- just double the amp hr of th batt for that setup you use .
there are new cells on the market that are lighter and yet provide much more instant power
as a suggestion - go the the new 2500ma JR NiMh or the 2500ma packs from Cheap battery Packs .com
the JR/ Spektrum radios run perfectly on 6v packs - so you get better, faster response to boot
a simple charger -even the one that came with your set will charge the 4.8 2500ma packs --actually a 24 hr charge on that charger is good for a couple of first time cycles - to properly condition the NIMh cells - then -buy a decent inexpensive NiCad /NiMh charger with variable output
stay away from LiIons and regulators -frankly- tho they are popular - the simple NiMh route is better.
why?
because -it is simpler
ask Danny--

jetjockey69

My Feedback: (31)

balsa,

just a suggestion: use 2 Rx batteries for your airplane. A week point in any battery system is the switch, especially in any glow or gas powered model, so any model in which I have more than $500 invested, I use two Rx batteries, each with it's own, heavy duty switch, to power my Rx. In larger models, those batteries feed a "power expander", etc. so that the servos get full power while the Rx is fed power at the proper voltage without any loss due to amperage drain from the servos under load.

Two 6v, 1500mah NiMh batteries feeding your Rx is not a lot of weight for a .61 size model and provides redundancy and greater capacity, which equals peace of mind!

At_Your_Six

By the way, did not AMA put a big article in their magazine last year about how they did a lot of testing of the DX system? Does anyone still have a copy of that? I wonder if AMA knows anything about this issue, if any members have reported any accidents due to loss of control with the DX7 and AR7000 setup.

Six

skyriter

Yes. As far as batteries go, you can get 4 cell (4.8V) or 5 cell (6.0V) that have the same connectors and will plug into your radio system with no adapters required. With 6 volts, you will need a charger that can handle the 5 cells. Some have a cell switch on them. As far as NiCd or NiMH, the plugs are the same.

Bruce

balsafire

My Feedback: (4)

Hey all
Thanks for the helpful replies. I got ahold of an old buddy of mine where I used to live. He is in the electronics field and makes his own packs. He hooked me up with some 6v, 2400 Mah packs (3) for future this and projects. Thanks again for all the help. If not for reading this post I just might have lost a plane to ignorance. Hope this helps others avoid a costly mistake. "dumd thumbing" a plane in is bad enough, let alone a simple set-up failure.

I do think Horizon should step up to the plate on this. Everyone knows you need enough battery. However, I'll bet a lot of Spektrum users are not aware of this potential "reboot" situation if using their supplied rx pack. They advertise it as suitable for large scale planes where it is a sure bet that higher load servo's will be used. It should not be assumed that the user knows an upgrade is needed. There are a lot of good pilots who's forte is flying, not building and set-up. Education is needed from the manufacturer to fully understand and operate their product.

I will say that Horizon has always been great with me when I have had issues with their products. Product support is outstanding.
Just my 2 cents
Rod

dsnyder

Sorry to hear of the problem. You absolutely must size the battery pack to the model you intend to use, the more servos you use, the larger capacity battery you will need. This is the case regardless of the radio system used.

At_Your_Six

Sorry to hear of the problem. You absolutely must size the battery pack to the model you intend to use, the more servos you use, the larger capacity battery you will need. This is the case regardless of the radio system used.

_____________________________

Danny Snyder
Horizon Hobby / Team JR

Hi Danny

Yes I agree. The radio came with a 2000mAh pack to run four digital servos and that is one of the packs that crashed. I have to say I just talked to another pilot in my club today and he lost his airplane last week flying a DX7 and an AR7000. He was flying a park flyer using a BEC; he had a un-commanded right roll into the ground also. Danny I real think Spektrum needs to look into this, I don’t think it’s a low voltage issue now I think you guys got a bug in the software like the AR6100 had. Just my two cents but people are not happy right now.

Six

dsnyder

The DX7 comes with an 1100 mah battery which is fine to run the servos included. That sounds like a BEC cut off with the other pilot. There are not any trends of problems with the AR7000 receiver. I'm personally using them in 6 aircraft and helis currently without having any problems.

At_Your_Six

The DX7 comes with an 1100 mah battery which is fine to run the servos included. That sounds like a BEC cut off with the other pilot. There are not any trends of problems with the AR7000 receiver. I'm personally using them in 6 aircraft and helis currently without having any problems.

_____________________________

Danny Snyder
Horizon Hobby / Team JR

Thanks Danny,

I have one AR7000 that has worked each time I use it, like I said, I am not hear to bash Spektrum just want the info so it does not happen again. I an using now a 2700mah pack with no problems so far.

Six

John Redman

My Feedback: (8)

You talk of a hard right roll with the loss of control. When you initially turn your model on does the right aileron go up, or maybe the left aileron go down, or one of the elevators do the same as stated above? Or do all the control surfaces sit at neutral until the link is made?

If any of the control surfaces move to some crazy position, you will need to rebind the system to change this. Once you complete a plane setup you should always rebind to ensure everything is centered and straight in the event of a power failure/loos during flight. This is called the smart safe/fail safe setting.

At_Your_Six

"You talk of a hard right roll with the loss of control. When you initially turn your model on does the right aileron go up, or maybe the left aileron go down, or one of the elevators do the same as stated above? Or do all the control surfaces sit at neutral until the link is made?

If any of the control surfaces move to some crazy position, you will need to rebind the system to change this. Once you complete a plane setup you should always rebind to ensure everything is centered and straight in the event of a power failure/loos during flight. This is called the smart safe/fail safe setting."

Hi John,

Rebinding was done after both planes were completed and no control surface movement happened at Rx power up. All control surfaces acted normal. After both crashes each plane's ailerons were in their full opposite positions, like a hard right roll had been commanded. I do not think the Rx went into failsafe due to the positions of the ailerons, like you said they would be in thier neutral state per a failsafe event. I have been a Spektrum user for over a year with the DX6 system so I have seen the porblem you bring up before and know to rebind the system if those issues come up.

I am still flying one AR7000 Rx in my last 40 size airplane and have not had a problem like with the other Rx sent back for eval. I called Horizon last friday and they had no news on my AR7000 Rx, they said they should be completing the eval sometime this week. John I would like to asked a favor, can I get some feedback from service as to how the Rx was tested and if they found anything. I would like to put this issue to bed so I can go flying with peace of mind again.

Thank You

Six

skubacb

PCM zero lost a/c. Spektrum 4 lost a/c. In all cases I had more than enough battery. The smallest was a 4.8v 1650 and the biggest a 6v 2700. Largest a/c was 60 sized with 5 digital MG servos. All batteries are less than 8 months old. Last crash was on takeoff with a fully charged (Multiplex charger) battery. So I know it was fully charged and it was the first flight of the day. Receiver was a 7100 and the transmitter was a DX7. The plane had about 50 flights with the Spektrum system. The last flight everything was working until just after takeoff roll when the aircraft went uncommanded and did a slow roll to the left and into the ground.

The following day a foamy with a fresh battery, Phoenix 25 controller, 6100, and the DX7 transmitter about 2 minutes into the flight did not respond to inputs and took a rolling dive into the ground.

In both cases, once everything was placed on the bench at the field everything worked perfectly.

All connections are of the Deans type, heat shrunk, or safety clipped with the SonicTronics connection keeper. Batteries remained connected to the reciever and had sufficient voltage for the anticipated flying.

I bought the Spektrum specifically to not lose a plane due to someone else turning on on my freq. But I have no lost a/c with PCM and four lost a/c with Spektrum. I am beginning to regret my radio change. Something is not right but I know not what.

dsnyder

Have you sent the system in for a check up?

At_Your_Six

Hi Craig,

Sorry to hear you have lost two airplanes to this problem. I am still waiting for some word on my Rx AR7000 that I sent back, over two weeks now and nothing. It is good of you to share your story on this forum, maybe Spektum will take it more seriously now.

Keep Up The Good Fight!

Six

skubacb

My TX was replaced after the second time I sent it in. I lost two aircraft sent the radio in and told them I could smell an electrical smell when I adjusted the gimbal springs. They said it was ok and sent it back. I lost another aircraft and sent it in a second time. They said the "deck" was bad and replaced it. My last loss was with the new TX.

The last two losses were not during 3D flight. One was just on a down wind to final. Straight and level when the a/c acted like our old time glitching - control/no control - erratic flight/control/no control erratic flight/control etc. that lasted about 10 seconds. The last loss did not include erratic flight just loss of control at take-off (new TX).

Another member of our club lost an Andrew Jesky Extra 330 electric with the same erratic switching between control and not. One a/c I was able to save. It was a little higher so I was able to do some pointing away from the ground between the erratic sections. A real heart pumper. Because of the new TX I thought (wrongly) that my troubles were over.

rino

My Feedback: (121)

Is there a trend with this loss of control thing or is it just differnt issues causing similar problems? Hopefully, we will get some info on this sooner than later. They can either analyze it and tell us how to avoid having it happen or provide a SW update. Either one would be a confidence builder.

zoott

Well this gives me confidence for the maiden I'm about to do.

onewasp

Just wanted to tell you all that there is indeed a "Promised Land"!

I personally have been flying the DX7 since its announcement------more sets in operation than I can list (that is the unvarnished truth).

We've got zero crashes and zero malfunctions. Our fields therefore must indeed be "The Promised Land" :-).
History has shown that we have a rather "normal" past experience on radio performance-----so this leads us to believe that the DX7 is very, very reliable.

We did have one relative newcomer (about 7 years in the hobby) who claimed he had a problem and that he damaged his A/C on its maiden DX7 voyage.

The verified story is that he took it out of the box, briefly charged his batteries then tried to fly. He swore he had "bound the system". The facts are that he could not "remember" how the binding process was done. Do you believe that?-------we don't. Neither does anyone else around here.

I'm presently at the point where I'll have to know more about the flier's experience level and attention to the 'dreaded instructions' before I'm going to exhibit any further concern.

Our collective experience here has been that the DX7 is performing better at this time than the FM/PCM systems-------Nope, we don't have one failure-------but as with any mass produced item I'm certain that one will appear sooner or later----shear numbers if nothing else.

Systemic problems-------not one sign.
Sets in the greater area------LOTS----the DX7 really has a following around here. Most (not all) of our fliers are experienced. A/C size 42% through Pattern sizes.

Our experience----NOT YOURS -------I understand that.

Sorry you've had the experiences stated-------but it certainly isn't systemic or we would have had some sort of sampling here--------we simply don't.

B58

My Feedback: (43)

I only have a few flights on my DX-7, but so far zero problems. Wonder if the 2.4G is just more sensitve to RF problems at some fields? Maybe a cell phone tower, microwave link, etc. Our field is fairly isolated, but the missile range is fairly close with a lot of RF flying around. So far no problems, now where is some wood to knock on. Bob

dsnyder

There are not any trends of problems with the DX7 or AR7000 receiver.