all axis do the same thing, i swapped all the axis cards and amplifiers form a working machine and it remains the same, i also swapped the power board but nothing, the strangest thing is that when you move the x axis the y axis moves too, any ideas?
A little more info please...
ALL axis are doing "that" when you move a single axis?
In the video, what are you doing with the handwheel? And when does it start that
*SHUDDER*?
From your bit of info, I'm going to make an attempt to explain what I think it is..
DC drives.. You have an encoder that tells the machine WHERE the motor is and you
have a TachoGenerator (or some such non-sense).. The TachoGenerator tells the control
how fast, and in what direction the motors are turning. The TG uses +12 and -12v, and
as far as I can tell, its the ONLY thing in the machine that uses -12v.
I'm trying to remember exactly how this works.. But the TG creates a voltage, so many
volts per rpms, positive one way, negative the other way.. If you pull either the +12
or -12 off, you get a runaway... The control then thinks the motor is going a million
miles an hour one way, and it pours on the power to counteract that movement(that isn't
actually happening) and you get a runaway..
If you have a dead spot on the TG, when you hit that dead spot, all of a sudden the control
sees that the axis is taking off, and it will try and counteract that, and then it hits a good
spot on the TG, and realizes "Woops" too far, and reverse and come back to the dead spot, overshoot,
rinse and repeat and you end up with a NASTY VIOLENT oscillation... My first instinct is that
is what I'm seeing as your motor is walking across the floor.
If something is pulling down your -12v, it will make all your axis do stupid shit at the same time.
If it was the +12v, the machine would shut down, since +12v is used for many things, as is +5v.
From what I can see, I would be chasing the -12 volts.
There are capacitors on the axis control cards(1010) and a few of the other ones that bridge the
+12 and -12. On the boards I have here, capacitor C20, the second one up from the bottom
as the board sits in the machine, and on the inside, near where the board plugs into the machine.
If you need to start chasing things, that info might help.
Don't ask how I know this, but If ONE of those capacitors has a
short, the machine will be FINE, until you try to power up the motors, and then
you get a run away... For some reason, it only draws down the -12v, and the +12v
is fine.
IF one of those capacitors has an intermittent short..???? <-- this is just a thought..
But I would concentrate on the -12v from what I can see.