Help! Most likely cause of temporary loss of control/motors on Mini Guinea?

dahacker

Member
My son flew his Mini Guinea again today. Two instances, different flight batteries. Both problems happened mid battery usage.

First instance, loss of both motor power for a second or two, but no loss of servo control. Second instance loss of both motor power and servos for a second or two. Both problems were singular and didn't result in a crash. Also, both motors cut off at the same time, no differential thrust occurred. Motors were not at full throttle either. Batteries (800mAh 3S and 1300mAh 3S on the separate flights) were well above 3.8V per cell at landing.

Transmitter: Spektrum DX9
Receiver: Lemon RX Stabilizer PLUS LM0044 (stabilizer and plus disabled) DSMX
Motors: Current A pack twin
ESCs: Current A pack twin (Yes we calibrated the throttles) (Also, no differential programmed in on transmitter)

Possible contributing factors:

1. Both ESCs are plugged into the receiver WITHOUT the power wire clipped on the second one.
2. DX9 transmitter battery is a 2S LiPo and was at 7.3V
3. Other

What is the most likely cause of the likely signal problem of the three above? When if ever does the DX9 range lower based on the transmitter input battery voltage?

He has flown it for three batteries with the transmitter at full charge prior to these two flights with no problems.
 
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NickRehm

Member
I would say radio brownout and receiver failsafe kicking in, but the fact that it happened twice with different results each time contradicts that.

Possibly loose battery connection? My thought is the first issue, the ESCs saw a loss of voltage very briefly and had to reset the motors but no effect on BEC. Then the second issue was a little longer loss of voltage where BEC cut out too.

Try tugging on the battery/ESC connections to see if the ESCs rearm themselves at all
 

Merv

Site Moderator
Staff member
Could by loose battery connector, could be low Tx battery.
Has the Rx been in a crash? Sometimes this will damage the antenna(s). Look where the antenna(s) enter the case for damage. Sometimes Rx’s just go bad.
 

dahacker

Member
We haven't had a chance to yank on the power wires yet. If we don't find a problem with the power wires/connectors. Would a "glitch buster" be advisable to smooth out any receiver power voltage issues coming from the ESC?
 

whackflyer

Master member
1. Both ESCs are plugged into the receiver WITHOUT the power wire clipped on the second one.
I would eliminate that one. Just pull up the tab on the power (red) wire on one of the ESC servo ends and just pull the wire out. Then when you want to use the power wire again just push it back in and make sure the tab is down.
 

mrjdstewart

Legendary member
I would eliminate that one. Just pull up the tab on the power (red) wire on one of the ESC servo ends and just pull the wire out. Then when you want to use the power wire again just push it back in and make sure the tab is down.

or find a small servo extension and pull the wire from it so you are not possibly damaging the plug on your ESC. servo extensions are a dime a dozen.

with that said, i never bother to pull the wire and have never had issues with any of my twins. i just make sure i am using identical ESC's.

laters,

me :cool:
 

dahacker

Member
or find a small servo extension and pull the wire from it so you are not possibly damaging the plug on your ESC. servo extensions are a dime a dozen.

Both of the ESCs are on servo extensions since the ESCs are actually on the wing. So it shouldn't be a problem.
 

Bricks

Master member
How long was he flying before this happened? I have had similar problems from batteries that have a high resistance Still think it is a good idea to pull the extra ESC wire can but not always cause weird issues...
 

Piotrsko

Master member
The events point to a common cause which has to be either the esc with the red lead attached, the receiver or transmitter. In my experiences, on my futaba 6ex, if you ignore the beeping from Hades warning on low battery. (8.6 v) , eventually the signal output get squirrelly. The 6ex also is motor pulse first, so motor issues to me means I have LOS events going on. Your transmitter is probably different. 2.4 ghz is really wierd for small wattage control systems, EVERYTHING affects reception.

Too many issues to control for, so I would start with using the other ESC to power , and try a different flying site
 

dahacker

Member
How long was he flying before this happened? I have had similar problems from batteries that have a high resistance Still think it is a good idea to pull the extra ESC wire can but not always cause weird issues...

Definitely mid battery, but well above 3.8V per cell.
 

Bricks

Master member
Definitely mid battery, but well above 3.8V per cell.

That voltage is at rest tells nothing when battery is under discharge, high resitance will not let the battery put out the amps that may be required to keep everything running and still show voltage as normal. Not saying this is the problem but just something to consider.

Does your charger give resistance while or after charging I know I have a few that are at pushing 180 to 200 and will fly fine until the plane calls for more power ie motor servos etc.
 

Bricks

Master member
Just another thought have you checked for a binding control surfaces or bad servo you may be over driving the BEC causing this issue.
 

dahacker

Member
That voltage is at rest tells nothing when battery is under discharge, high resitance will not let the battery put out the amps that may be required to keep everything running and still show voltage as normal. Not saying this is the problem but just something to consider.

Does your charger give resistance while or after charging I know I have a few that are at pushing 180 to 200 and will fly fine until the plane calls for more power ie motor servos etc.

We have a low voltage alarm attached to the battery balance plug in flight. That would trigger if the voltage sagged. There doesn't seem to be a correlation between throttle draw and the problem, but we don't have enough instances to be sure yet.
 

Bricks

Master member
Some of these problems can be a pain to track down as we see in this instance, might have to just try and swap things out. Let us know what you do finally find.

I had an issue with a stabilization receiver where I had to add a capacitor to one of the open ports on the receiver. In certain instances the stabilizer needed more juice when doing many corrections at once. Now that particular stabilizer comes with a capacitor. That being said I have never had that problem with the Lemons.

I am just shooting in the dark here can`t you tell...LOL
 
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