Mastering / Recovery questions

Since you are new with the Fanuc robot, stay away from Quick Master. It can be so confusing as to not be quick at all.

In any likely scenario where you absolutely must have an Image to restore, you will probably not be able to move the robot... until the Image is restored.
PM me with your questions about your Master/Cal. I'm sure I can help you.

USURP_RUR

You should also get with Racermike123 on this forum for mastering issues, and the restoring of Image backups

1. An image should be taken after your robot is in good working order with all software installed. Typically after it completes its first program cycle correctly. However any updates to the program's over time or tweaking that have been done to the robot will not be in the image so it's crucial that you keep programs backed up as well. We do them twice a week at my plant. After we load an image onto a robot we then load the current programs IE most recent. Robots with DCS you will have Pulse coder alarms if the robot is not in the same position when the image is restored that it was in when the image was taken.
2. To check mastering jog all of the robot axis to 0 degrees using the position window or a zero program and look at the witness marks they should be lined up pretty closely.
3. Zero master is with all axis at 0 degrees. Quick master is for tight spots where it's impractical or impossible to get the robot axis to zero degrees. When you do a quick master you must scribe the robot or mark it somehow otherwise you have no way of knowing where to line it up at to quick Master it.

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M

1. If I'm ever going to have to restore controller image, do I need to bring the robot to the same point where the image was taken? This is the best way, but sometimes you don't have this option due to a failure. Should I just take each robot to ZERO and image them again? No. run them to a home position and take the image.

2. I don't know the location where the robots were mastered. If it is factory mastering it was done in the fixture master position. Do I need to know this if I ever have to remaster them? No! If so, how can I find out the last mastering location?

3. Zero Position Master vs. Quick Master. What's the difference, which one should I use? (remember all my robots are working)
Zero position master is done with the robot at the zero position. Quick master can be done at any position. The trick is that you need to bring the robot back to that position to restore the mastering.
Quick master requires you to create a reference position, let's say at the zero or the home position. If you lose mastering you move the robot as close to that position as possible (I think it's supposed to be 5 motor revolutions) and then restore the mastering with quick master. If you don't create the quick master reference then you can't use quick master.

Generally you will not need to master every axis. Only one. In the last 3 years I have done single axis master 10 to 1 over zero position master. A motor will fail and you use single axis master for that. In my case I see motor failures far more often than battery or cable failures that require zero position master.

Change the batteries every year, do backups 4 times a year and whenever something is changed and you will keep repairs under control.

As long as the pulsecoders haven't been removed/replaced (or generally the relation between the robot's actual position and the signal from the pulsecoders remains unchanged), the trick with $DMR_GRP.$MASTER_DONE and calibration afterwards should be enough - but a confirmation on this would be appreciated

1. Controller problem - I need to reload the image.

I have an image taken at the HOME location (can't get to ZERO on some robots).
The Lithium battery dies, wiping programs, data. Need to reload the image.

If I move the robot to the home location where it was imaged (scribed marks) and reload the image? Will I need to re-master?

No, you will need to reset the pulse coders and calibrate.
So you restore the image and the robot has a pulse mismatch alarm.
You reset the pulse coders, calibrate, and you are all set. No touch up needed.

2. Robot problem - I need to perform mastering.

Mechanic pulls out robot's alcaline batteries by mistake. BZAL alarm on all axis...
I don't know in which location the robot was originally mastered and I can't reach ZERO. What happens if I re-master at HOME but it was originally mastered at some other location, will all my thought points be off?

This is the fun one. First you kill the bonehead that did this.
Now you have a robot that needs mastering on all axis. The best thing to do is zero position master it but you don't have the space to do that.
I have this condition on several robots and there are plenty of options to handle it.

1). Quick master; set the quick master reference at the home position. Paint witness marks on the robot so that if the robot isn't at home you can get it close and then perform quick master.
2). Single axis master. Line up 1, 4, 5, and 6 and single axis master them first if you can. Then rotate axis one so you can line up axis 2 and 3
to perform the single axis master on them. Axis 2 MUST BE AT ZERO TO SINGLE AXIS MASTER 3.
3). If the controller power has not been turned off you can go to the position screen and write down the joint angles which will still be correct, IF THE POWER HAS NOT BEEN CYCLED. In order to reset the BZAL you will need to reset the pulse coders and cycle power. When the robot reboots the joint angles will have changed. Write them down again. Jog each axis until the pulse not established errors are resolved and put the robot back to where the second set of joint angles that you wrote down are. Now go to the single axis master page, enter the joint positions from where the robot was BEFORE power was cycled into the master positions and master the robot. Calibrate the robot and check your points.
This method has worked 100% for me and no touch up was required, ever!

For options 1 and 2 you will need to check and correct any tool frames user frames and check all points and back it up.

Theoretically yes, but quick master doesn't always work that well.
You will always have to check your positions.

So, if i move the robot to marks and i press Zero position master.
The next step is press CALIBRATE and correct the angles to +/-0.2 deg???

So, if i move the robot to marks and i press Zero position master. Yes
The next step is press CALIBRATE Yes
and correct the angles to +/-0.2 deg??? I don't know about this

Quote from Racermike123

So, if i move the robot to marks and i press Zero position master. Yes
The next step is press CALIBRATE Yes
and correct the angles to +/-0.2 deg??? I don't know about this

I,ve readen in the manual that when you do the CALIBRATE, the error of the joint angles must be between +/-0.2 degrees to be sure that the encoders will work fine

Quote from tomexx

Great explanation!

Final question:
The robot is mastered to some position now but I don't know where.

Should I / could I Set Quick Master Ref right now, say at HOME pos so I could later Quick Master from that position if mastering was needed? OR would that required touch-ups?

About the final question, you can know where the master position is if you move all axes in Joint Mode to 0 degrees (visualizing the Position screen), and the physical position of the robot is the master position.