justinlb917

hi idk whats going on, i have lost three planes in the last month ( 2 1/2 weeks) the first plane i lost was on the old dx7 with a ar6200 i had my batteries fully charged and went around a circle and landed because of badly tuned engine as i was just about to taxi back from my landing my plane went totally nuts on me and flew on the ground straight towards us at 100 mph about 20 feet away from me it regained signal (at this time i was unaware of where my finger was because i was telling every body to get out of the way) and the plane fliped up and crashed because i had the stick in the corner. i sent it into spektrum and of course they said nothing was wrong as usual (before i said i was experencing a delay and had sent the dx7 in for a firmware update and the first day out the crashed happened) and since i was so/so about the radio i decided to get a discount on the new dx7s. so after this crash i put a brand new ar6210 in a "gp super sportser" and i went up for fist flight with all new batteries and the new dx7s first flight it flew great refueled went up again and the plane totally lost singnal and crashed! i thought the battery had come loose from the switch and unplugged itself so i let it go. The next plane (gaupner 300s) i had put the o so relible ar7010 and the exzact same thing happened with it, full charged battery and every thing but this time everything was clipped and locked down so nothing could pull apart. went up for the first flight ( first flight with dx7s i had flown it before on the dx7 !) it flew great landed and refueled and went up as soon as i took off the plane started to climp i had no controll at all. the plane went into a million peaces smashing everything (including receiver and servos) i dont know what to do!!! is it the radio? or the receiver i have never had a problem with airtronics i fly a cap 232 with a mokie 212 radio rds8000 airtronics and 8 channel reciver please please help! -justin

GeicoGecko

Have all the crashes occurred at the same location? Has anyone else had issues on 2.4 GHz?

Franco2fly

We need more information...  First question I have would be, have you done a Range test?  Next question would deal with the RF environment. DSMX is a more solid 2.4Gig system than the older DSM2.  I'm pretty sure the 6200 will only do DSM2, the screen on your newer DX7s should indicate what scheme it is using.  The only other area of concern would be the batteries.  "Fully Charged" is a nebulous term and batteries are the crucial part of any system.  The only sure way to tell if a battery is "Fully Charged" is to measure the voltage while the batteries are providing current to a servo that is under load. ie. not just centered, but gears moving.  Here's a contrived example to indicate what I am saying.

Let's say you head out to the field after pulling the wall plug charger off the plane, batteries in the plane you think are fully charged.
You get to the field pull or push the switch on, after fueling up.  In our mythical plane, I'm gonna say that the throttle servo, is fully back, and actually when you switched from the Dx7 to the Dx7s, the servo centering is a little different such that this servo is too far back and heating up since its in a stalled state.  Now those batteries are dying quickly.  If there's a bad cell, it won't take but a minute or two for the pack to drop well below the 3.8 volts required to maintain link.  Next thing you know the surfaces are going to the present failsafe position.

I know I made all of that up just to give you an example of what could happen.  Remember I started the response saying "Need more information"   How big is the airborne pack, what kind of servo's are you using, have you checked for any servo stalling.  Have you tried running the system for 5 or 10 minutes straight while pinning the plane to the ground and running it at half throttle?  Lastly, has anyone else had reception problems at your flying site?

Be sure and post your findings, it helps all of us get smarter.


KKKKFL

justinlb917

ok the batteries were 6v 2200mah tenergy batteries i started using them about 6 months ago and they worked like a dream and yes ido range tests before i fly in the situation im having spektrum tells me that it can only bea battery problem and this is why the receivers didnt go to failsafe mode but nimh batteries just dont die!! they might have voltage fluxuations but nothing so seriuos that there "new"receivers (dsmx) that are not supposed to brown out browned out!! and when i check my nimh batteries i have it under 1 amp load and plus on this last crash i was just taking off!! i was not using much voltage !! and yes franco my old dx7 was all dsm2 i replaced it with the new dx7s witch i have all dsmx receivers and the screen does display to me weither or not it is in dsm2 mode or dsmx mode.

GeicoGecko

One of the things I'm confused about is if the tx lost comms with the rx, the rx would enter fail-safe mode and the throttle would go to minimum (not maximum unless you had the throttle on max when you bound).

justinlb917

i had the battery locked down and rapped with foam rubber and the ends clipped so nothing could pull apart and no i didint bind my radio with it at full throttle! and yes its it very strange that it did not go into failsafe thats why spektrum says it has to be a power issue but i flew the thing 2 minutes before! and the voltage was great! the night before i had run a complete disharge/charge cicle in it !

ian51291

Hi Justin,what i found with the failsafe is that if you bind the rx and then have to reverse the throttle servo ,when it goes into failsafe the throttle will go to fully open,you have to re bind it after you have reversed the servo.
Ian.

ian51291

Hi Justin,what i found with the failsafe is that if you bind the rx and then have to reverse the throttle servo ,when it goes into failsafe the throttle will go to fully open,you have to re bind it after you have reversed the servo.
Ian.

BuschBarber

My Feedback: (2)

With a Spktrum radio, a Failsafe event occurs when the receiver loses the Link (signal) from the transmitter. There is no Failsafe event if the receiver battery goes dead or if you have a Brownout due to low receiver battery voltage. Checking the receiver battery voltage before each flight is good, but it will not ensure that you will not have a Brownout. You need to exercise all your servos, by vigorously moving the transmitter sticks, while measuring the voltage between the receiver battery and the receiver, with a Wattmeter or Hangar 9 Current Meter in line, once in a while. The receiver battery voltage could read fine, with the servos at rest, but under heavy load, your system could draw enough current to drop the receiver voltage below critical.

Franco2fly

+2 for what BuschBarber said.

I was astounded when I was exercising a set up using a smallish 1300mah battery.  Now this battery had not come right off the charger, but I was surprised at what the servo's were drawing when vigorouslys moving the sticks.  I'm not so sure that Voltage, or current draw is your particular problem, at least from your descriptions.  I can tell you that Digital servos draw more than the old Analog ones, and stalled servos are DEATH to any plane.  If you have eliminated the battery, and stalled servo, then I think you need to examine the RF environment.  Are there other 2.4Ghz flyers that do not have problems at your flying location?

I fly with a bunch of Gypsie flyers, and one of their locations was near the end of a busy International Airport runway.  I can't be certain, but I believe there were times when the 2.4Ghz airport terminal surface search radar swamped the band of frequencies as it painted a Model just after lift off.  The guy was about 100' in the air.  This is pretty extreme.  I would re-check all of the connectors looking for a broken wire inside the plastic connector.  Also pay attention to the orange light indicator.  To my way of thinking, you should NEVER land and see it blinking.  The last time I flew at that location I describe just above, I landed and the receiver was flashing indicating there had been a link loss.  I never recognized any erratic flight behavior, but it sure gave me angst about flying at that location again.


KKKKFL

justinlb917

yes the night before i had disharged and chrage the 2200 mah 6v battery and it put in 1735 mah the battery voltage on the second flight( the crash flight) was at 6.36v under 1amp load so it was pretty charged and no i never reversed the servo.