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Robodrill 5th axis troubleshooting

thunderskunk

Cast Iron
Joined
Nov 13, 2018
Location
Middle-of-nowhere
Strap in, it’s gonna get dicey.

I have a 2004 Fanuc robodrill T21iDL with 16iMB control. At one point in its life, it had a 5th axis hooked up to it. Unfortunately, it is not the same 5th axis that came with it when I bought it used. The table I have is a Nikken 5AX-2MT-105. Double spindle, tiny little guy.

Cables on the machine side were installed by a tech who actually knew what he was doing (as opposed to me). We got it all hooked up, and quickly discovered the power/signal and feedback cables between the table/machine and inside the table were all shot. I bought new cables and installed them myself (not a great plan). That… encompasses more than 6 months of work with ridiculously excessive lead times on every cable, connector, nut and bolt. The only way I can describe the experience is pain. Physical, emotional, rectal, etc.

Current state: I start the machine. It loads, turns the drives on, and the rotary table moves say 30 degrees in both axes. It stops, and the following alarms pop up:

410: servo alarm : C axis excess err
483: monitor safety function error
490: CNC safety function error
300 APC alarm: A axis need ZRN
300 APC alarm: C axis need ZRN

At one point I had a 436 C-axis soft thermal OVC alarm, but it’s gone and hasn’t come back. I had battery alarms, but that was before I fixed most of the parameters, and they’re gone now.

There is a pneumatic locking feature; I don’t have air hooked up to the rotary table assuming it’s fine to troubleshoot electrical connection without it.

It has one limit switch with two dogs on a ring and one deceleration switch used for home with one dog. I mixed these up initially, but have since connected them as they should be.

I changed the parameters per Nikken’s requirements, though two particular ones I was unable to change;
1828 position deviation limit value while moving
1829 position deviation limit value at stop

When I try to change these values, the HMI flashes “write protect” and doesn’t make the change. I have parameter write enabled. According to the techs, this is because of a password protection. Fortunately my electrician knows the previous owner, unfortunately the password he gave me didn’t work.

Posting here is a fling against the wall hoping something sticks. Running out of money fast, and I’ve got work waiting on this mill to get going.

So…
Any ideas on why I have a “write protect” on just two of the many parameters I need to change?
Any ideas on how to recover or remove parameter password protection?
Any thoughts on the cause of these alarms?
If the table moves on startup, does that mean my drive board isn’t burnt out?
 
One more piece of info: with these alarms, I can’t move any of the axes. What’s worse is each time I start the machine, the table rotates a little more. At some point, the tilt axis will exceed the slack of cables going to the rotary axis, so I’ve only got… three startups to solve the problem before I’m kinda screwed.
 
I can't help you but I EXTREMELY EMPATHIZE with you and hope you can get it figured out. Best bet i would think is an independent fanuc tech. Need to have the "secret decoder ring" to figure this stuff out. Without it you're most likely hosed!

I am sending out good energy to the universe to help you get it figured out....:cheers:
 
Only question I have is, when you get the 410 alarm, is there any alarm number on the axis drive?

Also, you probably know this, but it shouldn't be moving when it starts up. Sounds like some sort of runaway situation. Does the screen show it moving?

Are you sure that each motor cable and the encoder cable related to that motor is in the right slot, and not swapped? It might be trying to hold position on A/B but it's moving C.

Does the machine correctly see those axis as rotary and not linear?


You could pop open the 5th and decouple the motors if you really need to.




I guess that first question wasn't the only question i had...
 
As Dandrummerman mentions, it sounds like the control is catching a runaway and stopping the axis. Did the drives for the nikken table come with it or were the drives already in the machine? If they were already in the machine, are you sure they are compatible with the motor/encoder combo and scales on the rotary axis if equipped?
 
Only question I have is, when you get the 410 alarm, is there any alarm number on the axis drive?

Also, you probably know this, but it shouldn't be moving when it starts up. Sounds like some sort of runaway situation. Does the screen show it moving?

Are you sure that each motor cable and the encoder cable related to that motor is in the right slot, and not swapped? It might be trying to hold position on A/B but it's moving C.

Does the machine correctly see those axis as rotary and not linear?


You could pop open the 5th and decouple the motors if you really need to.




I guess that first question wasn't the only question i had...
All good questions though. Now that I think about it, the reason the techs plugged the cables in the way they did is because I labeled them when I bought the machine with colored tape. I almost wonder if they were labeled incorrectly, and now the feedback cables are on the wrong axes. Swapping the two is easy enough as nothing is buttoned up, but if that’s the case, I’ll either need a new cable for the rotary as the other cable is too short, or swap it inside the cabinet. Both things I’m inclined to let my electrician figure out in a few weeks.

Drives show a dashed line and no numbers. I only tried to see it once, but I dare not waste another power cycle given my cable length predicament.

Nikken and Fanuc said the table moving is normal for first hookup. Something to do with not knowing where home is. I thought it was weird too, but they said it.

If it comes down to it I probably will pull the tilt cables.
 
As Dandrummerman mentions, it sounds like the control is catching a runaway and stopping the axis. Did the drives for the nikken table come with it or were the drives already in the machine? If they were already in the machine, are you sure they are compatible with the motor/encoder combo and scales on the rotary axis if equipped?
Drives were in the machine. Given the techs were confident they could install it with the drives that are in there, I think they’re compatible. Doesn’t mean they are though.
 
Are you sure the servo in the rotary table are compatible with the drive? I know when one of our customers specs a table, we ask for the drive type in the rotary and we then supply the drive that is compatible with that table.
 
End result was a bad board. Two actually. The off button on the HMI has never worked. Not something I realized was an issue, but you can run the machine without it. You can't do certain parameter changes without it. There's a board in the back that has issues as well. Not a drive, but I couldn't tell you exactly what it was. End result was we finally got the 5th axis to move with the jog handle, but the techs said it wouldn't work in NC. I ran out of money just to troubleshoot it and buy new cables, so it's a 3 axis for the time being again.
 
End result was a bad board. Two actually. The off button on the HMI has never worked. Not something I realized was an issue, but you can run the machine without it. You can't do certain parameter changes without it. There's a board in the back that has issues as well. Not a drive, but I couldn't tell you exactly what it was. End result was we finally got the 5th axis to move with the jog handle, but the techs said it wouldn't work in NC. I ran out of money just to troubleshoot it and buy new cables, so it's a 3 axis for the time being again.

Can you tell me what boards you replaced?

we have a t14iBL with a similar issue (that I put in bold above)

The power off button "works" but only if you don't have e-stop pushed in. If you have e-stop pushed in, hitting the off button does nothing. Moreover, when you undo the e-stop (this only applies to the one on the control, not the one on the pallet changer), the machine shuts off.

Just wondering if it is the same failing board.
 








 
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