"Ignoramus28206" wrote in message
...
This is about putting a gear motor on the axis.

I am very puzzled.

I have this servo gear motor mounted on the knee. It is a 65V motor,
4.4 amp continuous and 26 amp maximum. 15:1 gear reducer.

http://igor.chudov.com/projects/Brid...ntrol-to-Knee/

It works fine and if I apply power to it from a large battery charger,
it goes up and down very well.

The next thing I did is I connected it to a A-M-C 30A8 drive, the same
kind as what I have on all other axes.

http://igor.chudov.com/manuals/A-M-C/30A8-Datasheet.pdf

This servo drive gets 72V DC power from the same DC power supply as
all other drives.

I have NOT connected this drive to EMC2 at all, and I send it a analog
signal from just a little DC power supply.

I tried torque mode and velocity mode.

It behaves VERY weirdly. If I tell it to move the knee down, it moves
it a little (think 0.5 inch), and then stops and the knee actually
comes back up (like by 0.1 inch)!

It does not move it up by more than 0.1 inch and does not come back,
as in the opposite example.

I am struggling to find an explanation.

The only one that I can come up with about this going down behavior,
is that perhaps the pneumatics of the pneumatic knee support is
messing me up.

Or, perhaps, this is a bad servo drive.

I am at a big loss, any ideas would be most welcomed.


You need to adjust your counterweight or connect active feedback before it
can be properly tuned.