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Topic: Servo burnt (ball and beam) (Read 217 times) previous topic - next topic

Leoch

Hello everybody,

I have developed a ball and beam project with my Arduino, and It worked pretty well !

But after a couples of minutes, the servo stopped working, it was very hot so probably I burnt it.
I replaced it with a new servo ( they are both servo MG996R), but after a while, the same problem.

I opened them, and I noticed that the potentiometer and DC motor still worked fine, so in my opinion is the circuit inside that burnt, not the motor.

(For those of you who will say the resistant torque is too high, with some calculations i proved that the torque of my servo is largely enough)

So, do you have any idea why servo broke ? maybe the reason is that it burnt because it must keep
moving continuously, switching from a value to another without peace ( basically it never stays still).

Same suggestions before buying the third servo please ?

thanks in advance

jremington

#1
Apr 20, 2019, 06:51 pm Last Edit: Apr 20, 2019, 06:51 pm by jremington
Quote
So, do you have any idea why servo broke ?
Yes, you abused it in one or more of several possible ways.

For more information, read and follow the instructions in the "How to use this forum" post.

Paul_KD7HB

The stall current is 1.4 amps, so I guess if that condition happened for an instant, you would get instant heat inside the small box. Is that possible?

Paul

jremington

#3
Apr 20, 2019, 07:42 pm Last Edit: Apr 21, 2019, 03:05 am by jremington
Conversely, if the servo was overloaded, that high current condition would not happen for just an instant.

Leoch

Stall current is 2.5A, but however I don't think that just an instant stall current broke my 2 servo.

(I used them for an heavier robotic arm and I have never had problems)

Southpark

#5
Apr 21, 2019, 12:23 am Last Edit: Apr 21, 2019, 09:05 pm by Southpark
suggestions before buying the third servo please ?
Try operating the servo (after you get another one) for a while without load, or with a 'light' load.

You mentioned - 'used for robotic arm' - but that isn't necessarily comparable to the system you have right now --- as in what sort of 'actual' loads and torque is being encountered by the servo motor in this different application. Mode of operation is important too. Such as - robot arm might not move continuously, and the servo module has time to cool down between movements.

jremington

Quote
however I don't think that just an instant stall current broke my 2 servo.
I don't either (reply #3).

MarkT

Hello everybody,

I have developed a ball and beam project with my Arduino, and It worked pretty well !

But after a couples of minutes, the servo stopped working, it was very hot so probably I burnt it.
I replaced it with a new servo ( they are both servo MG996R), but after a while, the same problem.
RC servos are not designed for heavy mechanical loading.  You need a metal bodied robotics-grade
servo if you want it to do work.  RC servos are designed just to move control surfaces in small RC planes
which is not a heavy load.
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I opened them, and I noticed that the potentiometer and DC motor still worked fine, so in my opinion is the circuit inside that burnt, not the motor.
Yes, quite likely.
Quote
(For those of you who will say the resistant torque is too high, with some calculations i proved that the torque of my servo is largely enough)
The rated torque of a servo is peak, not continuous duty unless explicitily indicated - the specs for
these cheapo hobby grade devices are dubious at best of course
Quote
So, do you have any idea why servo broke ? maybe the reason is that it burnt because it must keep
moving continuously, switching from a value to another without peace ( basically it never stays still).

Same suggestions before buying the third servo please ?
Much higher torque rating than continuous required torque, metal gears, metal body
Quote
thanks in advance

[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

justone

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But after a couples of minutes, the servo stopped working, it was very hot so probably I burnt it.
OK I will ask the question that has not been asked.

How are you powering (what voltage is your supply) this servo?

Sounds like you are over voltage on it if the servo heats up in minutes.

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