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Help! Motor goes our when trying to turn

#23
A second ESC of the same type might show the same issue. A different manufacturer of ESC might not show the same issue!
The Rx does not have a lot of filtering onboard.
A Capacitor is effectively just a filter, (a bucket of voltage that can supply large current for a short time - normally enough to smooth out the voltage in the event of spikes and surges, only).
Smaller or different servos may have less surge currents!
As for my preference I would fit the Capacitor anyway as it makes the system less susceptible to inrush current issues for all time!

Just my thoughts!

Have fun!
Thank you
 

Hai-Lee

Old and Bold RC PILOT
#24
One final thing to test!

Disconnect the servo output arms so that the control surfaces are disconnected and try it again. If the problem disappears then either the control surfaces are not free enough for your current setup or your pushrod connections could be binding causing far too much servo operating current and high surge currents.

Have fun!
 

Bricks

Master member
#27
Are you sure your battery is up to snuff it acts just like a battery that has high resistance or low voltage bad cell. Put the prop on once and see what you get with the servos disconnected.
 
#30
One final thing to test!

Disconnect the servo output arms so that the control surfaces are disconnected and try it again. If the problem disappears then either the control surfaces are not free enough for your current setup or your pushrod connections could be binding causing far too much servo operating current and high surge currents.

Have fun!
I did this and they still twitch and turn off the motor so there isn’t any binding issues
 

Hai-Lee

Old and Bold RC PILOT
#31
I did this and they still twitch and turn off the motor so there isn’t any binding issues
Based on that, it looks like the start current of the servos is shutting down the 5v rail. So the first thing to try is the capacitor to see if it improves!
By the way the servo I mentioned previously that got hot and eventually melted the case was still turning but one of the gears was split and every time the servo tried to move the gear expanded and acted like a break on the motor causing the current to soar. The servo still moved until of course the case started to melt and then the servo just locked up.

You could check the servos to see if any are getting hot.

Have fun!
 
#32
Based on that, it looks like the start current of the servos is shutting down the 5v rail. So the first thing to try is the capacitor to see if it improves!
By the way the servo I mentioned previously that got hot and eventually melted the case was still turning but one of the gears was split and every time the servo tried to move the gear expanded and acted like a break on the motor causing the current to soar. The servo still moved until of course the case started to melt and then the servo just locked up.

You could check the servos to see if any are getting hot.

Have fun!
Good tip I will take this into consideration thank you all for your help
 
#33
OK. Obviously the Rx is shutting down! Unfortunately I could not read the Rx volts during the problem as your hand was covering the Tx screen.
Do you have any electronics knowledge? The reason I ask is that I would try fitting a capacitor, (1000uf 10V) across the Rx voltage supply rail. This can be done by either soldering the capacitor to an old servo lead, a modified bind plug, or by jamming in into the rear of the pins of one of the servo leads where they plug into the Rx.

Some ESC/BECs have plenty of filtering on their outputs and some do not, (I suspect that price is the usual determining factor). The servos do have an input surge current and if the BEC has poor filtering and the Rx has no filtering then the surge can cause the 5 volts to spike. This spike can cause the Rx to enter Low voltage reset or some indeterminate operating area. In addition servos need a clean and stable supply or the positional feedback is upset and the servos will jerk and stutter, (sometimes even reverse rotation directional momentarily).

If you can try fitting a capacitor and see if the issue disappears!

Have fun!
Thank you for this tip I tried the capacitor and it worked perfectly thank you very much I ended up using a 16v 820uf because of the 3s lipo I am using but none the less the airplane now runs flawlessly thank you
 

quorneng

Elite member
#34
Glad it is fixed but it is still a bit strange.
I have never had to add a capacitor to the Rx supply rail even on planes than have 7 servos all working at once.
My fear is the capacitor is just 'masking' a problem that may come back and probably just when you don't want it.