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Fix an over-extended servo?


#1

In some recent code experiments I goofed and sent my nice little pololu $5 microservo some, uh, odd pulse widths. And now it’s not happy. I’m guessing these are basically disposable after this? Nothing simple inside I could do? Just wondering.


#2

I take servos apart all the time, and manage to get them back together and functioning. Yours may be possible to repair and at this point, what have you got to lose?


#3

Perhaps my sanity? :slight_smile:

I’m just thinking I burned out some component and was wondering if this is a common thing with too long pulse widths. And what component that might be. Guess I should research what is inside them.

But you are right, might as well poke about in there.


#4

Hello, Martan.

It is not uncommon for a servo to be damaged when sent a pulse width outside of the 1-2ms range. When that happens, the servo can hit its mechanical limit and possible destroy itself. You can read more about standard servo pulses in this blog post.

By the way, if you were trying to find the limits of your servo when you damaged it, you might find it useful to read the second to last FAQ on the Maestro FAQ tab, which explains our recommended procedure for figuring out the maximum possible range of motion from a servo.

-Jon


#5

Actually, I was coding a servo control algorithm for an Attiny 1634 when I did this. Came out pretty good in the end but I neglected to pull the servo off before a round of tests and sent it like 50ms pulses, oops. Such a cute little servo too, hate that I toasted it.

Oh, did I mention how much I love slo-scope on the USB AVR programmer? GREAT APP!

martinsant.net/?p=1563

Too bad I didn’t consult it before frying my little friend :frowning:

But alas, after opening it up, it’s obvious I’m being silly. Nothing in there. Motor and SMD, that’s it. I zapped it. Darn. Oh well, five bucks, not too bad and it died a noble death.