Robot losing position while moving

pacijent

Hello to all, what would be the best way to check brakes and gears in IRB 6400 with S4C controller. Client is reporting that robot is missing programmed point from time to time by couple of millimeters. Thanks in advance. 

graemepaulin

Is the move command using a zone or fine point?

If a zone it is allowed to deviate from the programed position by the size of the zone.

Brakes are not used during movements (decelerates and holds on the motors), except for emergency stop while robot is moving.

I think an issue with the gear would be causing issues all the time as they rotate many times during a movement.

xerim

Is absolute accuracy enabled?

Hoki

Hi
I don´t know the application but your robot is 22 years old and I think robot has gearplay. You can check the oil plugs if there are iron particles on it and the colour of oil/grease.
Also you can make a testprogram and move axis for axis at full speed. Then release the eneble device on TPU and you should see which axis has play. 

mgenbox

Hello
Anyone ever see a robot bouncing along a flat move L?  This is on an IRB 6700 around 7 years old.
Watching the Jog screen Z looks like it deflects 1-2 MM causing the core around 35 lbs to drop out of the vacuum gripper with the speed setting above 50%. 
Not getting any faults.  Motor going out or SMB failing possibly?

           MoveL Offs(pPick_Left,0,0,95),v80,z1,toolCORETOOL3\WObj:=wobjCOREMACHINE;

            SetDO DO_PN_Left_Warmbox_Eject_BWD,1;

            PulseDO\PLength:=1.5, DO_EN_Tool_Blowoff_1;

            PulseDO\PLength:=1.5, DO_EN_Tool_Blowoff_2;

            !rToolBlowOff_On;

            MoveL Offs(pPick_Left,-1100,0,95),v2000,z10,toolCORETOOL3\WObj:=wobjCOREMACHINE;

Thanks for any suggestions!

lemster68

If you don't have a fine point in that first move the robot read ahead will execute the following lines, possibly causing the blowoff to occur too soon.

mgenbox

Lee

OK but the issue I am having is the robot moving along that second Move 1100 MM is the tool is "bobbing" up and down and no faults.  Wondering if a motor or the SMB issue?  thx

lemster68

Do you have the tool load and payload defined correctly?  And is there any arm load present?  If so, has it been entered into the system parameters?