PID SERVO TUNING

i can try that first think tomorrow morning
you mean to disconnect plus and minus 10 volt right?

if the motor oscillate without the plus minus volt wires what is the conclusion?

Hi
i disconnect the +- 10 volts and the oscillation remain

Did you disconnect the wires at the drive, or at the Mesa card? If at the drive, hat would imply that it is a tuning problem within the drive. (or some other problem with the drive.) If at the Mesa card, then the wiring between the Mesa Card and the drive, could still be a suspect (picking up interference from place.)

How about some details on the machine, the drives, and their history. You mentioned that this is a conversion of an existing machine. Was the machine and drives functional not long before the conversion or is this a resurrection of some old pile that had been abandoned for a long time? What kind of servo drives are you dealing with (make, model)? Is it possible that the drives parameters were stored in volatile memory that was backed up by a battery that has long expired?

i disconect the wire in the mesa card
the machine is a INTERMAC 1500 gantry roter with double y motor and c axis
the driver are 4 pieces of BRU 200 and one piece of BRU500 and a Osai10 controller
the machine was stored in a warehouse for about 4 years
i dontr now any other info for the machine
i have some question : is it possible to controll a machine of this type with velocity control in c axis
and torque mode in the rest axis ?
i wonder because i manage to tune the c axis motor

The mode of control doesn't really mater much, and has no real bearing on your problem. Each joint plant is independent of all of the others in Linuxcnc, and they can be controlled in what ever mode they require. If you desired you could have one joint be torque mode, one velocity mode, one position mode, and if there were any other modes available you could have one of each of them as well.
The only significance the mode of control has, is in how the axis pid loops are tuned (and in the case of position mode commanded.)

Regardless, with 0 input from the control (the analog wires disconnected). There should be no movement at all with a torque command input, and little or no movement (a little drift is possible) for a velocity command input.

Either the wires for the analog command are picking up voltage from some RF interference or a short circuit, the drives are badly out of tune or misconfigured, or there is something wrong with the drive, or a problem between the motor and drive.

If the machine sat without power for 4 years, it is possible parameter settings in the drives could have been lost.

thank you for the very in lighting details
Monday morning i will have a technician an i will try to fix the RF interference
just for the conversation if the drivers have lost the settings is there a way to re tune them?

According to the manual.
www.axcontrol.com/pdfs/bru-500.pdf
(Amazing what you can find if you let Google be your guide.)

According to the manual to tune the motor or use the AUTO TUNE FUNCTION of the driver i have to use a TANDY 102
(PAGE 36) that is not possible
Is that the approach i sud use ( try to tune the motor) or act like the motor is tuned correct and try to fix wires and interference?
any suggestions??

I have no experience with these drives, so I can't say for sure. But I think you might be able to use an ordinary PC with a serial port, and a basic com terminal (see pg 62.). Google searches brought up examples of people using Hyperterminal to do it.