Something Curious

[JavaRN]

Servo no 6 (the one on the left foot) is behaving a little strange. After using the battery for some time (so it is not fully charged) it sort of blocks while moving, when the battery is ok it works normally. Is there a reason why only this servo blocks when the battery starts to loose power? or is there something wrong with this servo (may be gears are not functioning properly).

Thanks a lot for your help.

[Sazabi]

maybe there's something with greas on gears?so when battery is not fully charged, servo power reduces and it stalles.

[JavaRN]

Unfortunately the situation got a little worse. I recharged the battery today and the servo repeated the symptoms again with the battery fully charged this time. Do you think I have to change the servo? I have two extra hitec HSR-8498HB servos but the horn is on the other side and the numbers on the horn do not match that of servo 6. This is the first time I am changing a servo, can anyone suggest what steps are needed to change it. How do you know that a servo is actually burned? this particular servo does not hold if you press it a little hard in one direction but does hold firm if you press it the other direction.

I appreciate your feedback. Thanks again

[Sazabi]

I would disassemble it and check gears, if they're ok,than replace servo. What do you mean by "This is the first time I am changing a servo, can anyone suggest what steps are needed to change it"? just follow instruction of assemble backwards to dissasemble nova, and than assembleit again with new servo.
Try to use HMI Serbo programmer to check if servo works well with it.

[JavaRN]

What I meant by "the first time ....etc" is that are there anything I have to be careful about. I've assembled and disassembled the robot many times to make add-ons, but this is the first time I am changing a "standard" servo.

The gears look ok (nothing broken), so I will try to change it today. Unfortunately I don't have an HMI servo programmer, so I will connect the new servo to the robot with no brackets, set it to the zero position and then attach brackets and see if everything works. As I said the Horn is on the other side and so the new servo will be a little different than the previous one.

Thanks.

[i-Bot]

You should mount the servo with the same orientation and position as the one you replace.

If the wire now comes out the wrong side, break out the tiny plastic bit and do this to move the cable to the other side,

http://robosavvy.com/Builders/i-Bot/servwire.jpg

No HMI programmer needed if you replace

[Sazabi]

I meant check brocken servo with HMI programer

[JavaRN]

Thanks all for your feedback, I'll try it tomorrow, and I'll keep you informed.

[JavaRN]

I mangaed, it took me less time than I thought! Thanks guys for your help.