Left ankle turns into weird position in default pose

[zupa]

Hi, I got my robonova few days ago and finished assembly yesterday. At first I was hit by the most annoying misinformation in the manual with the servo slots, which I was able to fix with this thread.

After that, robonova took it's default pose.. well almost. For some reason it's left ankle is turned up as the following image shows:



I'v checked horn alignment and servo connection quadzillion times and everything should be okay. Here's a picture of the left ankle servo horn, just to make sure i didn't get something wrong:



Every other servo works as expected, i've uploaded the template program and it does all the moves when controlled with remotecon.

Any ideas, could that left ankle servo just be broken?

[RobotServicesGroup]

So when does the robot flip up the ankle? Just when you turn it on? You say it performs the standard motions, does the ankle flip up after a standard motion stops? Your servo hone alignment matches the way we have built ours. You might want to open the overall template and search for the standard_pose subroutine. It should look like this

standard_pose:
MOVE G6A, 100, 76, 145, 93, 100, 100
MOVE G6D, 100, 76, 145, 93, 100, 100
MOVE G6B, 100, 30, 80, 100, 100, 100
MOVE G6C, 100, 30, 80, 100, 100, 100
WAIT
RETURN

Check if any of your numbers are different.

[i-Bot]

Is the servo hone fitted correctly to the servo output shaft? Although the shaft and hone are keyed, it is possible to force it on out of position.

[zupa]

Is the servo hone fitted correctly to the servo output shaft? Although the shaft and hone are keyed, it is possible to force it on out of position.

Yeah, the shaft and hone's hole match so there should not be no problem.

So when does the robot flip up the ankle? Just when you turn it on? You say it performs the standard motions, does the ankle flip up after a standard motion stops? Your servo hone alignment matches the way we have built ours. You might want to open the overall template and search for the standard_pose subroutine. It should look like this

standard_pose:
MOVE G6A, 100, 76, 145, 93, 100, 100
MOVE G6D, 100, 76, 145, 93, 100, 100
MOVE G6B, 100, 30, 80, 100, 100, 100
MOVE G6C, 100, 30, 80, 100, 100, 100
WAIT
RETURN

Check if any of your numbers are different

standard_pose routine matches yours. The ankle turns up right after I turn on the robot on and stays that way through all the moves. So I have to support it to prevent falling.

Servo also gets hot if I keep it too long running since it's trying to turn past it's motion range.

Edit: It gets hot even when I removed the feet and hone so there shoudn't be nothing blocking it. I'm no expert in servos but seems to me it's broken in some weird way.

[RobotServicesGroup]

There are a couple more things you could try. First, you could re-assemble the ankle with the servo hone twisted a few notches the other direction. This might get the robot to stand, but you will probably lose flexibility in the opposite direction. Another alternative would be to move the ankle servo to another spot on the control board and see if it happens there too. If you shake the servo, do you hear anything rattling around loose? You could open the servo up to see if anything appears broken, but this might void your warranty. It probably wouldn't hurt to contact Hitec, or wherever you bought the robot, and ask for help.

[zupa]

There are a couple more things you could try. First, you could re-assemble the ankle with the servo hone twisted a few notches the other direction. This might get the robot to stand, but you will probably lose flexibility in the opposite direction. Another alternative would be to move the ankle servo to another spot on the control board and see if it happens there too. If you shake the servo, do you hear anything rattling around loose? You could open the servo up to see if anything appears broken, but this might void your warranty. It probably wouldn't hurt to contact Hitec, or wherever you bought the robot, and ask for help.

I tried different slots in the control board and result was the same every time, servo just turns all the way clockwise and tries to go even more.

I also tried to clear robonovas memory so no program error would cause this and again, same result, turns all the way clockwise and stays there.

Gonna inspect the servo bit closer but I think I'll contact Hitec and try to get servo replaced.

Problem is that I'm importing these things to Finland and replacement is going to involve shipping servo abroad and back. I want to play with my robonova today!

Anyway, thanks for your replies and helpfulness!

[zupa]

It was a broken servo indeed, got today a replacement from hitec. Finally able to play with robonova!