# Servos keep breaking, why? **URL:** \ **Category:** General Guidance\ **Created:** [February 8, 2025, 11:21am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695 "2025-02-08T11:21:00Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 8, 2025, 11:21am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/1 "2025-02-08T11:21:00Z")
Hi guys, im working on pen plotter, using Arduino nano on CNC shield as a controller. I use SG90 9g (plastic gear) and MG90 9g (metal gear) servo for pen lifting. Both types keep to break after few hours of working. There is no sound from servo when it is broken. Servo get warm during operations, but not hot. I power servo from external source set to 5.7V. Servo rotates 90 degrees, depending on printing type there are more or less operations, but in general: - the torque isn't big, there is very small weight to lift and a weak rubber for pressing pen down - typically there are up to 2 operations per second (rather less) - I add delay of 0.2 sec after each operation command to give servo time to execute fully (to avoid moving pen when it could still touch or not yet touch the paper) Can anybody tell me whether I do something wrong to cause the damages or these servos are just so bad quality? If it is about the quality, can you suggest a reliable one within reasonable $ range? ---
**Author:** ![bobcousins](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/bobcousins/32/221530_2.png) [@bobcousins](https://forum.arduino.cc/u/bobcousins)\ **Post date:** [February 8, 2025, 11:31am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/2 "2025-02-08T11:31:04Z")
> [@tmztmz](#): > > Can anybody tell me whether I do something wrong to cause the damages That's impossible to say on the information you have given. We would need a wiring diagram at least. In principle if you are powering the servo with 5.7V it should not fail. As for a quality servo, it depends on where you are, as shipping can be a significant cost. ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 8, 2025, 11:35am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/3 "2025-02-08T11:35:42Z")
Wiring is simple - servos red cable goes to +5.7 of external source, brown goes to ground common to whole system (power source, arduino, CNC shield) and yellow is the signal connected to arduino D11 pin ---
**Author:** ![ahsrabrifat](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/ahsrabrifat/32/1126412_2.png) [@ahsrabrifat](https://forum.arduino.cc/u/ahsrabrifat)\ **Post date:** [February 8, 2025, 11:41am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/4 "2025-02-08T11:41:37Z")
> [@tmztmz](#): > > Hi guys, im working on pen plotter, using Arduino nano on CNC shield as a controller. > I use SG90 9g (plastic gear) and MG90 9g (metal gear) servo for pen lifting. Both types keep to break after few hours of working. There is no sound from servo when it is broken. Servo get warm during operations, but not hot. > > I power servo from external source set to 5.7V. > Servo rotates 90 degrees, depending on printing type there are more or less operations, but in general: > > - the torque isn't big, there is very small weight to lift and a weak rubber for pressing pen down > - typically there are up to 2 operations per second (rather less) > - I add delay of 0.2 sec after each operation command to give servo time to execute fully (to avoid moving pen when it could still touch or not yet touch the paper) > > Can anybody tell me whether I do something wrong to cause the damages or these servos are just so bad quality? If it is about the quality, can you suggest a reliable one within reasonable $ range? SG90 and MG90 servos are designed for 4.8V to 5V. Try to lower the voltage to 5V. ---
**Author:** ![Railroader](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/railroader/32/274550_2.png) [@Railroader](https://forum.arduino.cc/u/Railroader)\ **Post date:** [February 8, 2025, 11:43am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/5 "2025-02-08T11:43:31Z")
Have You taken a broken servo apart and inspected the interior? Is it a mechanical or electrical break down? ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [February 8, 2025, 11:55am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/6 "2025-02-08T11:55:05Z")
> [@tmztmz](#): > > there are up to 2 operations per second > few hours of working. That's 120/min and 7200/hr and 21600 for 3 hours. I would say you were lucky they lasted that long. ---
**Author:** ![bobcousins](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/bobcousins/32/221530_2.png) [@bobcousins](https://forum.arduino.cc/u/bobcousins)\ **Post date:** [February 8, 2025, 11:55am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/7 "2025-02-08T11:55:56Z")
> [@tmztmz](#): > > red cable goes to +5.7 of external source, And the external source is what exactly? ---
**Author:** ![camsysca](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/camsysca/32/1015228_2.png) [@camsysca](https://forum.arduino.cc/u/camsysca)\ **Post date:** [February 8, 2025, 12:01pm UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/8 "2025-02-08T12:01:59Z")
Beyond the other excellent comments so far, I have to ask - are you running 0-90 or 90-180, or have you set up to run 45-135? I've a couple of servos I suspect died because I was hammering limit-to-limit; setting up to stay away from end points might improve lifetime. Or Not. Lifetime on a $2 servo might be short regardless. ---
**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\ **Post date:** [February 8, 2025, 12:04pm UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/9 "2025-02-08T12:04:49Z")
I have $2 aliexpress SG90 clone running almost "non stop" 12h /day for two years now. Either your voltage is too high (measure) or you might have problem with your mechanical setup. ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 9, 2025, 9:48am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/10 "2025-02-09T09:48:43Z")
Let me answer your questions: - @bobcousins power source is 12V power adapter going through regulated step down converter. It was set to 5.7V and multimeter showed that value at the end of the wire (100cm) where it was just about to connect to servo. - @jim-p I provided worst case scenario. In fact it is much less. ChatGPT says these servo should last 100k-500k cycles (cycle=0-180-0) so I would say my servos were breaking much faster - @camsysca servo is 0-180 degrees, but it only operates in 0-90 range - @ahsrabrifat I have now lowered voltage to 5V and will make some endurance tests. But I'm a bit confused, since internet says these servo are fine for 4.8-6V. - @Railroader I didn't do it yet, but for sure it is not about gear damage (there is no sound from motor, also to reomve that possibility I tried with metal gear). ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [February 9, 2025, 9:54am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/11 "2025-02-09T09:54:05Z")
> [@tmztmz](#): > > ChatGPT says these servo should last 100k-500k cycles (cycle=0-180-0) so I would say my servos were breaking much faster If Chat said it should last 500K then you are obviously doing something completely wrong. We need to see code, a schematic and datasheets for all parts used. ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 9, 2025, 10:08am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/12 "2025-02-09T10:08:27Z")
@jim-p that's where we enter a dark area:) Part are from aliexpress, so no real datasheets are available, code is [GitHub - lavolpecheprogramma/grbl-1-1h-servo: This is a special version of grbl 1.1h version with servo support.](https://github.com/lavolpecheprogramma/grbl-1-1h-servo), which I cannot really edit due to complexity. Schematic is according to CNC shield V4 with fixes made according to [https://www.instructables.com/Fix-Cloned-Arduino-NANO-CNC-Shield/](https://www.instructables.com/Fix-Cloned-Arduino-NANO-CNC-Shield/) ---
**Author:** ![bluejets](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/bluejets/32/1013044_2.png) [@bluejets](https://forum.arduino.cc/u/bluejets)\ **Post date:** [February 9, 2025, 10:15am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/13 "2025-02-09T10:15:00Z")
You say the torque requirement "isn't big" but it's possible it is beyond the servo spec. ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 9, 2025, 10:40am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/14 "2025-02-09T10:40:28Z")
To be honest it's hard for me to say, don't know how to compare 1,6kg/cm to my setup. I reduced the max torque by replacing standard servo arm with a round knob, so that per degree rotated the pen lift the same amount of milimeters, and the whole lift is just about 5mm. Pen is forced down with a rubber that is quite weak. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [February 9, 2025, 10:41am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/15 "2025-02-09T10:41:13Z")
Your experience with those servos is not uncommon. Many others on the forum have complained of them being dead on arrival, rotating continuously or lasting just a few hours. However, we only here about the failures and not the successes but seems to be the luck of the draw with those servos. For hobby purposes, I've only used Futaba and Hitec servos. ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [February 9, 2025, 10:58am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/16 "2025-02-09T10:58:21Z")
I see the issue has been solved in your other topic on the same problem. > [@Nano GRBL pen plotter - issues with servo](https://forum.arduino.cc/t/nano-grbl-pen-plotter-issues-with-servo/1345567): > > Hello All, I'm working on a simple to build A1 format pen plotter, using Nano clone on CNC shield V4 clone. 2xNEMA17 on X axis, 1xNEMA17 on Y axis, SG90 9g servo for pen lifting. Once ready and stable, I will publish it! CNC shield was fixed according to [https://www.instructables.com/Fix-Cloned-Arduino-NANO-CNC-Shield/](https://www.instructables.com/Fix-Cloned-Arduino-NANO-CNC-Shield/), with additional trick to disconnect Arduino from Power barrel, so I can use 20v power supply safely. Arduino is powered via USB cable, together with data transmission. Basica… ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 9, 2025, 12:05pm UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/17 "2025-02-09T12:05:09Z")
@jim-p other topic was about unstable work of servo and it has been fixed by using external power source for servo. This topic is about servo breaking after some time of stable work ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [February 9, 2025, 12:06pm UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/18 "2025-02-09T12:06:02Z")
Was unclear. ---
**Author:** ![kmin](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/kmin/32/1147370_2.png) [@kmin](https://forum.arduino.cc/u/kmin)\ **Post date:** [February 9, 2025, 12:16pm UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/19 "2025-02-09T12:16:26Z")
> [@tmztmz](#): > > servo is 0-180 degrees, but it only operates in 0-90 range That doesn't matter if it's anyway hitting the limit on one side, make sure it's operating comfortably in the movement range. > [@tmztmz](#): > > Pen is forced down with a rubber that is quite weak. Your motor might be weaker. There's no practical way for us to valuate this "weakness" of the rubber. Do you have spare servo to make it run without rubber for few hours/ days to test if it fails? ---
**Author:** ![tmztmz](https://avatars.discourse-cdn.com/v4/letter/t/f07891/32.png) [@tmztmz](https://forum.arduino.cc/u/tmztmz)\ **Post date:** [February 10, 2025, 8:12am UTC](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695/20 "2025-02-10T08:12:41Z")
@kmin just confirmed, servo moves -45 - 45 degrees, so in totally safe zone. I know that saying "weak" about the rubber doesnt say much:) Once current servo breaks I will do the no rubber test. But for now it seems that lowering voltage to 5V makes servo much happier (but I have no statistics to prove it, since it didn't break yet) [Next page](https://forum.arduino.cc/t/servos-keep-breaking-why/1351695.md?page=2)