Vibration of the torch in Motoman SV3

[bbqa01]

 
HI  EVERYBODY !

I have some Motoman SV3, in the past I used it for pick and place applications. Now I want to use it for welding applications. But I can't do that because at low velocity (about 1cm/minute), the  torch (welding gun) is shaken 1 or 2 times a second, amplitude about 1 ->2 mm in any direction.  

I think reason of the vibration is caused by the gain of servo motors is low.

Everybody please help me answer that ideas about "gain" is wright or wrong and can I change the gain of servo motors in Motoman SV3 ?. How can I fix the vibration problem !

Thanks  

[bbqa01]

Nobody can help me !   

If anybody can use or used this robot for welding, Please teach me how to set the parameters of this robot ! and Please show me the values of those parameters.

Thanks everybody !

[motomaniaco]

 bbqa01 ,

The vibration is on teach mode or play mode?

I have used this kind of robot for arc welding and in most of the times the robot has a slighty vibration on teach mode, but on play mode there is not vibration.
Check the payload, may be you are using a torch too heavy, or the torch cables are too long. On this kind of robot you must to use a balancer for the torch cables.

[bbqa01]

The vibration is in any mode if robot move in slow speed. 
I think the vibration is caused by the gain of servo motor.I see in MOTOMAN K6SB there are a way to adjust the gain of servo and I wonder can I do that with MOTOMAN SV3 ?

Dear motomaniaco, you used SV3 for welding purpose, please teach me the parameters and values witch I must to set for SV3.

Thank you for your help !

[motomaniaco]

bbqa01 ,
On the ERC controllers it could be possible to adjust the gain on the sservopack, the manuals had the process. On the MRC, XRC and NX100 therte is no way to modifiy the gain of servos. It supposed that the gain set automatically when you initalize the system.
So there are two reason for the vibrating, I think, the first one is a failure on the speed reducer, you can check if the speed reducer has a mechanical failure. And the second one is a excessive load on the robot´s flange, you can check what is the load on the arm with the Tool Load Proccedure (SV3X Manipulator Manual, Section 3.11.3) wich is an automatic proccedure that calculate the tool load.

I hope this info helps you.

[95devils]

You don't say if the SV3 is connected to a MRC or XRC controller.  The servo gains can be adjusted but the parameters are Motoman only parameters.  The SV3 was notorious for having the shakes.  We describe it as having auto weave from the factory.  If you have the Yaskawa mode password and tell what controller it is connected to (MRC or XRC) I can tell you the parameters.  I have had to adjust these quite often in the MRC days. 

[bbqa01]

Thank motomaniaco  and 95devils.

I use YASNAC MRCIIs controller. I know a password :"00000000", is It Yaskawa mode password ?

motomaniaco and 95devils, please tell me parameters ! and teach me how to use MOTOMAN SV3 with MRCII controller for arc welding.

Thanks

[motomaniaco]

bbqa01 ,

I don`t know the parameters to modify the gain, It could be interesting to check them. The yaskawa password is in some posts here.

I think that right now the controller has the handling application, so first you must to change the application to ARC WELDING in order to use the ARCON, ARCOF etc, instructions.
1. Turn on the robot while press the CUSTOMER key
2. Introduce the yaskawa password
3. Select SETUP (move with the cursor keys)
4. Select APPLICATION
5. Select ARC WELDING
6. Select YES.
Turn OFF and ON the controller, check in one program if the controller has the ARCON instruction.
If you have FDE, do a backup before change the application, because this process will initialize some files. Also you can`t run programs with the HANDON instructions, the system will display a error message.

Good Luck!

[95devils]

Here's a list of the parameters that I used to adjust for this model robot.

SV1G032 - SV1G037   Load Inertia ratio, units is a %
SV1G080 - SV1G085   Position Loop Gain, units is in 0.1/sec
SV1G088 - SV1G093   Speed Loop Gain, units is in 0.1/sec

There are others that pertain to teach and play mode balance filter coefficients, I think that you won't need these as you said the problem was in both.