Let's Make Robots!

Nervous servos

Can anyone tip me off why my servos are so "Shaky" ? They are all grounded to eachother(+ the arduino Duo card) Lipo 7,4 connected to the servos and usb powers the Duo. 

 

Brg.

 

Alf Kåre

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Hi there! 

Im sorry for not responding, but ive been "too hell and back". I guess that my code is crap, so i wonder if anyone knows where i can find a working sketch with more than 1 servo, so i can edit it. I only seem to locate the "sweep" code from the arduino.cc site.

Try OddBot's code on how to drive up to 48 servos.

Will do!

 

it sounds like floating ground  a copy of code would help or check this out

http://arduino.cc/en/Tutorial/Button

http://arduino.cc/en/Tutorial/Debounce

hope this help

It is possible that your voltage is too high. A 2 cell LiPo is 8.4V when fully charged and most servos are only rated for 6V.

 

at too high voltage the same happened to me here.. the servo's are over-correcting their position. try it at lower voltage.

Could be all sorts of things.  On the heels of lumi's observation, my first question would be are you using the servo library or just PWMing them?  Is ther a condition in the code (an if or a switch) that causes slight variences in output on each loop?  Another would be what is the torque rating on these?  In my experience if you want a servo in an arm you want to make sure it has a higher torque than 200 oz/in. and preferrably in the 300-400+ range if you can afford it in terms of space/money.  A low torque servo can sometimes lift the load but not hold it still-kind of like the human arm trying to hold a brick out at arm's length with a straight arm.

Just as LMR prefer's English to include the widest range of robot builders, Very few countries use imperial terminology, please use metric where possible.

From the description given I doubt the problem is torque related as the arm was not under load.

 

The code would be of help here ... but yes, OddBot pointet it out..maybe it's just a timing issue or the servos are a cheap Monday production ;-)

How quickly are you updating your servos? If your software is trying to change the servo's position quicker than it can move it will jitter.

A simple test is to include a 20mS delay in your main program loop.