HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 15, 2006, 03:19 PM
Registered User
Joined Aug 2005
2 Posts
Discussion
Lost control of plane, is this a Rx or Tx problem?

Why would a plane fly on its own and not repond to commands? I recently lost control of my plane and it went off flying on its own.

The plane did not respond, just kept flying at a constant speed and altitude regard less of what I did on the transmitter. The problem happened when the plane was about 50 yards away, and it kept going until it crashed into a house about 300 yards away. Altitude was constant at about 10 feet. Can I be sure if the problem is in the transmitter or in the receiver?

I fly a scratch built scale Brewster Buffalo running off a brushless motor and a lipoly battery. It has a GWS 6 channel receiver, and an old Hitec Focus 6 transmitter, and has been in use for the last year with this equipment without any problems.

I am very spooked about this...
Jeff
craddojc is offline Find More Posts by craddojc
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 15, 2006, 03:32 PM
Registered User
Staffs, UK
Joined Nov 2003
10,270 Posts
Complete lack of control could be almost anything. The commonest causes are probably:
a) in the plane - failure of a switch or Rx battery if you're using a separate Rx battery. Could also be Rx, crystal or BEC failure but they're pretty rare.

b) at the transmitter - antenna loose/unscrewed or Tx output died.

You can tell if the Tx is still working o.k. with other receivers. It's not very likely to be an intermittent problem though anything's possible. You certainly need to check anything in the plane that's still intact. Bear in mind that if it was a severe crash the Rx crystal is likely to be broken now.

The last time I actually saw a problem like that some fool had not extended his Tx antenna - but luckily I got it extended in time and saved my plane .

Steve
slipstick is online now Find More Posts by slipstick
Reply With Quote
Old Nov 15, 2006, 03:45 PM
An itch?. Scratch build.
eflightray's Avatar
South Wales U.K.
Joined Mar 2003
12,900 Posts
Shouldn't your ESC have automatically shut the motor down with loss of signal? I thought all modern ones did.

Does anything still work?
eflightray is online now Find More Posts by eflightray
Reply With Quote
Old Nov 15, 2006, 03:59 PM
Frequent Flyer
wattsup_kz's Avatar
Kalamazoo, MI USA
Joined Aug 2003
2,892 Posts
Check the jack in the TX where the battery plugs in. On my Laser 4 the solder joints broke loose causing random shutoffs. Wiggle the plug with the radio on and see if it shuts off.

Brian
wattsup_kz is offline Find More Posts by wattsup_kz
Reply With Quote
Old Nov 15, 2006, 04:24 PM
Registered User
Palm City, FL
Joined Dec 2000
628 Posts
Quote:
Originally Posted by craddojc
I am very spooked about this...
You should have been around 20 or 30 years ago when radio failure was the norm instead of the rarity it is today!!

TimOBrien is offline Find More Posts by TimOBrien
Reply With Quote
Old Nov 15, 2006, 05:07 PM
ParkFlyer
xFxLxYxExR's Avatar
Joined Nov 2005
754 Posts
I have had that happen many times with those cheap GWS recivers. I guess its a "you get what you pay for" thing. Now you cant just say it was your reciver without some testing.

...XF
xFxLxYxExR is offline Find More Posts by xFxLxYxExR
Reply With Quote
Old Nov 15, 2006, 06:19 PM
Sayonara
JEB21's Avatar
Agoura Hills,CA
Joined Mar 2004
656 Posts
Quote:
Originally Posted by craddojc
Why would a plane fly on its own and not repond to commands? I recently lost control of my plane and it went off flying on its own.

The plane did not respond, just kept flying at a constant speed and altitude regard less of what I did on the transmitter. The problem happened when the plane was about 50 yards away, and it kept going until it crashed into a house about 300 yards away. Altitude was constant at about 10 feet. Can I be sure if the problem is in the transmitter or in the receiver?

I fly a scratch built scale Brewster Buffalo running off a brushless motor and a lipoly battery. It has a GWS 6 channel receiver, and an old Hitec Focus 6 transmitter, and has been in use for the last year with this equipment without any problems.

I am very spooked about this...
Jeff
Did you do a range check before taking off?
JEB21 is offline Find More Posts by JEB21
Reply With Quote
Old Nov 15, 2006, 07:02 PM
turn, turn, turn.
Athol, Massachusetts
Joined Oct 2005
10,234 Posts
One time I saw some hippe turn off his radio while attaching his strap.Fortunatly, after 1 minute of flying in circles, I managed to turn the radio back on and save the plane.
Kenny Sharp is online now Find More Posts by Kenny Sharp
Reply With Quote
Old Nov 15, 2006, 07:02 PM
Ascended Master
Sparky Paul's Avatar
Palmdale, CA
Joined Oct 2000
13,371 Posts
It sounds like a switch failure in the plane.
I've had that happen.
A battery failure usually ends in a crash just a few seconds after the failure.
Sparky Paul is offline Find More Posts by Sparky Paul
RCG Plus Member
Old Nov 15, 2006, 07:09 PM
Registered User
BlazerB52's Avatar
Fenton,MO USA
Joined Aug 2005
1,259 Posts
Was the transmitter designed for Alkaline batteries and you used rechargables?

There is a voltage difference of around 2.4volts. Could that be the problem?

Alkaline(disposable)=8X1.5v= 12v
Rechargables =8X1.2v=9.6v

That is what caused a problem for me.
BlazerB52 is offline Find More Posts by BlazerB52
Reply With Quote
Old Nov 15, 2006, 07:20 PM
Confirmed Chronic
screamin' eagle's Avatar
Pacific Palisades, CA
Joined Jul 2004
9,215 Posts
Does the transmitter use a soldered and shrink-wrapped battery pack, or one of those spring-loaded battery trays. On the latter, the contacts go bad and you lose power.
screamin' eagle is online now Find More Posts by screamin' eagle
Reply With Quote
Old Nov 15, 2006, 08:06 PM
Registered User
BlazerB52's Avatar
Fenton,MO USA
Joined Aug 2005
1,259 Posts
Screamin eagle,
Good point.

Had that happen also. Makes the thing go nuts when battery is jiggling in the TX. I don't use cheaper radio's anymore.

Hope problem is solved/found.
BlazerB52 is offline Find More Posts by BlazerB52
Reply With Quote
Old Nov 15, 2006, 11:01 PM
Registered User
Wilkes-Barre/Scranton, Pennsylvania, United States
Joined Nov 2000
6,276 Posts
I doubt that using "rechargeable" batteries instead of alkaline batteries would cause a problem. Transmitters are designed to operate over a range of voltages. Most "dry" transmitters--those that use alkaline batteries--also have after market rechargeable battery packs available to those who wish to use them.
Remember the voltage of "new" alkaline batteries is 1.5 volts. The voltage drops with use. Several of my radios come off my chargers with battery voltages of over 11 volts but quickly drop to 9.6 as I use the transmitter.
The moral of my story is the transmitter doesn't care what kind of batteries you use so long as the voltage is within the design parameters of the unit.

BM
BillM is offline Find More Posts by BillM
Reply With Quote
Old Nov 16, 2006, 04:49 AM
Registered User
vintage1's Avatar
East Anglia, UK
Joined Sep 2002
29,688 Posts
I think the key thing that someone has pointed out is that the motor didn't cut. ALL ESC's will go low throttle on loss of signal..if the motor kept going, it was getting signal.

Which means that most of the transmitter was working..or someone elses on the same frequency was, anyway.

Sounds like a subtle problem in the transmitter..might be low batteries, might be a fault - and a hard to find, intermittent and expensive one.

I would at this point toss the transmitter, and get a new one.
vintage1 is offline Find More Posts by vintage1
Reply With Quote
Old Nov 16, 2006, 09:35 AM
Oldie but goodie
Popsflyer's Avatar
United States, CA, Orange
Joined Jun 2003
3,890 Posts
What's the weight of this plane? I personally would be afraid to fly anything over 16oz with an old radio system and especially a GWS receiver. I actually threw away an old working Futaba 4ch system (about the same vintage as your Focus), because I didn't feel comfortable using it.

I've seen fly-aways before in RTF planes with cheapo radio systems (not your case) and heard of fly-aways with top notch PCM systems that locked the pilot out during a failsafe.

My first thought would be from outside interference. Many of the older radio systems were AM and are not as solid in todays crowded RF enviroment as our newer FM systems.
Popsflyer is offline Find More Posts by Popsflyer
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Servo, Rx or Tx problem? Time Pilot Electric Plane Talk 12 Jun 25, 2007 01:48 AM
Discussion Rx or Tx not working ? digsy Beginner Training Area (Aircraft-Electric) 9 Jan 13, 2006 05:25 PM
Is it my Rx or Tx? Up&Away Radios 7 May 17, 2004 12:54 AM
RX or TX Poblems? ExploreR Radios 8 Apr 09, 2004 05:08 PM
Weird ESC or TX problem LuckyArmpit Power Systems 0 Sep 11, 2002 10:24 PM