Buzzing noise.

The more technical aspects of Spirit, and carry-over discussion from Kickstarter updates.
eldaria
Posts: 3
Joined: Sat Oct 28, 2017 8:58 am

Buzzing noise.

Postby eldaria » Sat Oct 28, 2017 10:13 am

Hello.

When Spirit is turned on, even with a blank program there is a buzzing noise coming from the servos.
I think it is coming from the gripper servo, I base this on the fact that it feels as if the servo is getting slightly warm after it has been on for a while.
Also, When I disconnected it (After turning off and disconnecting the battery), then the buzzing noise stops.
Also I noticed thet it is not possible to turn it on when the servo is disconnected and running on battery, I could only turn it back on with servo disconnected when the USB was connected.

Is this normal?

-- Edit, on a second attempt It worked to start with having it disconnected, so i'm now using it without the gripper servo attached until I can get it confirmed why it is doing this.

Kevin
Posts: 154
Joined: Tue Jul 28, 2015 12:56 am

Re: Buzzing noise.

Postby Kevin » Mon Oct 30, 2017 5:08 pm

Hello eldaria,

Some buzz is okay. Sometimes when a servo is trying to set to a specific point it will buzz if there is resistance on it. Make sure you did the servo centering step correctly before attaching the gripper arms. When in the default position with the arms open, they shouldn't press against anything - just be sure they're not open so far that they're pressing on the sensors in front of the wheels.

Let me know if that helps.

-Kevin

romamaker
Posts: 11
Joined: Fri Sep 22, 2017 9:15 pm

Re: Buzzing noise.

Postby romamaker » Mon Oct 30, 2017 5:21 pm

Edit: I see that in the process of my responding, Kevin already had, but I'll go ahead and leave my response here too.

From what I understand, some buzzing from servos isn't necessarily a bad thing. It's basically constantly trying to hold its position. So if there's anything that could be causing any sort of slight load against the server (such as the gripper gears binding ever so slightly), it could be fighting against this and creating the buzz.

That being said, there is one thing you can check. During the build, I'm assuming you ran the "Servo Centering" routine? This ends up leaving the servo in a known position. (In this case, I think it's 110 for the gripper servo.) Then you have to install the gripper in a specific position, to match the know position of the servo. (Following the pictures in the install manual.) When you power up Spirit, it moves to servos to specific location. In the case of the gripper, it's opening the gripper up. If you installed the gripper too wide (open too far) to begin with, when it attempts to open the gripper during power on, it could be trying to open the gripper wider than what it physically can. You could try removing the gripper arms, and reinstalling just slightly more closed than what they currently are, and see if that helps reduce the buzz.

Of course, I'm still fairly new to this myself, so if anyone knows better, please speak up!

stardusts
Posts: 5
Joined: Wed Nov 01, 2017 10:40 am

Re: Buzzing noise.

Postby stardusts » Wed Nov 01, 2017 10:47 am

I had the same and I found out that the reason is my fault, I did not accommodate a proper gap between the two grippers as per the build instructions so when Spirit closes the grippers they both touch before the command finishes so the servo keeps on running. What I did is
1-remove the grippers
2-run the Center Servos sequence on page 59
3-reattach the grippers and this time with a bit more gap in between.

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TomTheWhittler
Posts: 12
Joined: Wed Sep 13, 2017 5:04 am

Re: Buzzing noise.

Postby TomTheWhittler » Wed Nov 01, 2017 2:19 pm

I remember having the same problem even though I did the sequence on page 59. I then backed off the gripper a little (gear tooth ?) and it got happy. It does not take much extra pressure for the servo to be unhappy and start protesting by buzzing.
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