This is your homebuilt JD robot with your own 3D printed JD, correct? The one you first discussed in this thread.

Are you using an EZ-Robot Lipo? Are you using EZ-Robot HD servos or HDD servos? Or are the servos not from EZ-robot?

yes it is me i attach a picture of my JD,i use an EZ-Robot Lipo and 4 servos from EZ robot and the rest from my stock servo MG996R.

I seriously doubt on battery. Is it lipo with min 1300mah n 20c. It happening because of current draw.. try to change power source.. let us know. Btw good jd.

The after market mg996 servos are not capable of handling the lipo voltage. The ezrobot servos are specifically designed for lipo batteries. The mg996 servos max out at 6 volts and the lipo is 7.4.

I also suspect the mg996 are Chinese knockoff because those are one of the most popular servos to knock off. Meaning they may not even meet the datasheet specifications.

The servos are being damaged by the lipo voltage. The datasheet for the mg996 servos is available online with a google search.

@vivion91, I was going to say what DJ said but he beat me too it and said it better than I could have.

My thoughts on fixing the problem are: If that was my robot I would (Option 1) consider upgrading all of the MG996 servos to EZ-Robot HDD servos or alternative servos rated for up to 7.4 volts

OR (Option 2) you could add voltage regulators to each of the mg996 servos to bring their voltage down to either 5 or 6 volts.

OR (Option 3) you could look for a 6 volt lipo that is bigger than 1300mah but also the same size dimensionally as the EZ-Robot lipo that way your battery won't exceed the voltage tolerance of the servos.

Your JD looks fantastic BTW! Great job!

Thanks for your help i will change theses servos